Paper - Studies of the intestine and peritoneum in the human foetus - part 6: Difference between revisions

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| [[File:Mark_Hill.jpg|90px|left]] This 1913 paper describes human fetal intestine development.
| [[File:Mark_Hill.jpg|90px|left]] This 1913 paper is the sixth in this historical series describing human fetal intestine development. Note many of the terms introduced in this paper are historic terminology, no longer applied to describing the intestinal anatomy and some intestinal developmental concepts have been reviewed since this early series.


See also historic paper {{Ref-Frazer1914}}
Other papers in this 6 part series by Douglas Reid:
 
# {{Ref-Reid1911a}}
# {{Ref-Reid1911b}}
# {{Ref-Reid1912}}
# {{Ref-Reid1913a}}
# {{Ref-Reid1913b}}
# {{Ref-Reid1913c}}
 
 
 
See also the historic paper {{Ref-Frazer1915}}
<br>
'''Modern Notes:''' {{intestine}}
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See the current page [[Gastrointestinal_Tract_-_Intestine_Development|Intestine Development]]
{{Gastrointestinal Tract Links}}  
{{Gastrointestinal Tract Links}}  


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{{Historic Disclaimer}}


 
=Studies Of The Intestine And Peritoneum In The Human Foetus=
=Studies Of The Intestine And Peritoneum In The Human Fcetus. Part VI=


By Douglas G. Reid, M.B., Ch.B. Edin., B.A. Trin. Coll. Camb.,  
By Douglas G. Reid, M.B., Ch.B. Edin., B.A. Trin. Coll. Camb.,  
Line 22: Line 32:
Demonstrator of Anatomy in the University of Cambridge.
Demonstrator of Anatomy in the University of Cambridge.


The Duodenum, With A Note On The Subdivision Of The Abdominal Cavity By Peritoneal Folds And Adhesions.
==Part VI. The Duodenum, with a note on the Subdivision of the Abdominal Cavity by Peritoneal Folds and Adhesions==
 
Synopsis of the Present Study. - The retro-duodenal fossae are first considered; then the retro-pancreatico-duodenal recess; the development of
the duodenum ; the relations of the peritoneum of the intestinal loop to the
duodenum; the special relations of the duodenum; and the genesis of
certain folds of peritoneum in relation to this part of the bowel. Lastly, I
consider points of surgical interest in connexion with the natural subdivision of the abdominal cavity into compartments or recesses.
 
 
Preliminary Remarks.—Cleland (see the Journal of Anatomy and
Physiology, vols. i. and iii.) was chief amongst those who in this country
advocated the displacement theory. He speaks of the duodenum “pushing
its way underneath the peritoneum of the parieties”; for “ other viscera
growing faster are thought to pull it (the meso-duodenum) away and
appropriate it” (Brockway in Gray's Anatomy, 1897). He regards the
left half of the transverse colon as being formed from “the terminal
intestine” (the part of the large intestine which extends from the colon
at the splenic flexure (see fig. 6) to the proctodaeum (Jonnesco) ). He states
that, “as far as is at present known, the adhesion of serous surfaces only
occurs as the result of pathological changes.”
 
At first, indeed, it may appear diflicult to see how, as first asserted by
His and Toldt, the still mesial splenic flexure of an embryo 25 mm. long
(see fig. 6) can gain the position it occupies in a foetus 37 mm. long (see
fig. 8).‘ In this country the wheels of the displacement theory were still
further sunk in the ruck by the writings of Bruce Young, Lockwood,
Treves, and others.
 
Byron Robinson (Journal of Anatomy and Physiology, 1899,
vol. xxxiii.) discusses the two “theories” (Toldt’s and other) without
 
1 Accordin to Flower (Medical Times and Gazette, 1872, vol. i.), the whole of the transverse colon is erived from the terminal intestine.
Studies of the Intestine and Peritoneum in the Human Foetus 487
 
prejudice; and gradually British authors have been coming to regard the
adhesion “theory” as the one which more probably expresses the truth.
 
Behind the head of the pancreas lies the fascia described by Treitz
(see fig. 9).
 
In front of the head of the pancreas there is also a layer of fascia
described by Toldt (“the pre-pancreatic fascia ” of Fredet, see figs. 5, 9).
 
No attempt has been made by those who advocate the displacement
theory to account for these fascias.’ One can hardly doubt (see fig. 5) that
they represent the meso-_duodenum. I have frequently demonstrated the
fascia of Treitz. So compact a layer may it form in the adult as well as
in the foetus, that it can readily be mistaken, at first, for normal endotheliumcovered peritoneum if the dissection to expose it has not been watched.
 
The prostato-peritoneal aponeurosis of Denonvilliersl also represents
the connective element of peritoneum (cf. fig. 6 in Part IV. of my “Studies,”
Journal of Anatomy and Physiology, vol. xlvii.).
 
But if any doubt could be expressed, I have, apart from all this, given
numerous illustrations of the_ truth of the statement" (which therefore
ceases to express a “theory ”) that two nolrmal endothelial surfaces of
peritoneum can adhere to one another.
 
Mall? states that it has been customary to call his second and third
loops of small intestine (his third loop corresponds to loop A in fig. 6, the
part there named “duodenum” being his first loop) the duodenum. “. . .
more mature consideration of models convinced me that loops 2 and 3
are finally transferred to the left side of the body to form the upper part
of the jejunum.”
 
How, then, is the mesentery at its root attached to the fourth (ascending)
portion of the adult duodenum ?
 
I have drawn attention to how certain folds of peritoneum may arise,
and have pointed out the particular variations of the small and large
intestine which result from displacement or from resistance to growth in
certain directions.
 
Treves has attempted to explain the origin of the inferior duodenal fold.
His explanation involves the duodenum being “drawn between the layers
of its own meso-duodenum.”
 
One must try, however, to determine how physical forces really do
operate in the production of certain of the peritoneal folds; for even if this
particular fold be present in “nearly all mammals,” it would, of course, be
 
1 “ En arriere de la prostate, entre les vésicules séminales et le rectum, existe une couche
membraneuse bien distmcte, que j’appelle 1-ostato-péritonéale-—par son bord postérieur,
elle adhere a cette portion du péritoine qui escend entre la vessie et le rectum” (Denou
villiers, quoted by Proust, La Prostatectomie, p. 160).
2 The Johns Hopkins Hospital Bulletin, Nos. 90-91, September—October 1898.
4488 Mr Douglas G. Reid
 
a complete mistake “to think that ‘heredity’ will build up organic beings
without mechanical means.”
 
THE RETRO-DUODENAL FOSS./E.
 
The retro-duodenal fossae which I shall now describe may be tabulated
 
as follows : —
(1) The retro—pancreatico-duodenal fossa.
(2) The superior retro—duodenal fossa.
(3) The intermediate, middle, or lateral retro-duodenal fossa.
(4«) The inferior retro-duodenal fossa.‘
 
The Ret'r0—panc'reatico—duodenal Fossa.-—This fossa (see figs. 1, 2) was
found by me in a full—time foetus. It is bounded in front by the first and
second portions of the duodenum, and by the head of the pancreas; behind,
by the parietal peritoneum in front of the inferior vena cava. On the
right it is closed in by the duodeno-renal ligament and the genito—mesenteric
fold. It extends towards the left as far as the aorta, and downwards as
far as the upper border of the third part of the duodenum. It opens above
into the vestibule of the lesser sac of peritoneum, and into the greater sac
at the foramen of Winslow. It results from the conversion into a fossa of
the retro-pancreatico-duodenal recess presently to be described.”
 
The Superior Retro-duodenal Fossa.—This fossa (see fig. 2) was found
by me in an adult body dissected at Cambridge several years ago. It lay
behind practically the Whole of the fourth portion of the duodenum. Its
orifice, situated opposite the duodeno-jejunal flexure, was directed upwards
and bounded on the sides by the free margins of two folds of peritoneum
which passed from the parietal peritoneum and the mesocolon at its root.
Its orifice thus rather resembles that of the duodeno-jej unal fossa described
by Jonnesco in 1889, and situated “au niveau de 1’angle duodéno-jéjunal,
entre son dos et la racine du mésocolon transverse.”
 
The Intermediate Retro-duodenal Fossa.—This fossa (see fig. 2) was
found, well marked, by me in five out of twenty of the 12- to 22—cm. foetuses
specially examined. It lies behind the fourth portion of the duodenum.
 
Its orifice, directed towards the left, is bounded above by the inferior
 
mesenteric vein and the superior duodenal fold; below, by the inferior 9
 
duodenal fold.
The depth of the fossa may equal, but never exceeds, the diameter of
the part of the duodenum to which it is related ('i.e. the fossa never passes
 
1 Discovered by J onnesco in 1893, and described by him as “ the retro-duodenal fossa.”
 
2 I have only recently begun to look for this fossa in the adult. It certainly appeared
to have been present to a slight de ree in a body dissected at Cambridge, Lent Term, 1913.
But, unfortunately, the dissectors Tied unconsciously enlarged it in a. downward direction
before I saw the exact state of afiairs.
Part of liver
(cut surface;
 
HeP3‘0—rena|
ligament
 
DL:o(ie:m—rmiaI
ligament
 
Mesocolonmfi
 
(cut)
 
Sheet of
 
peritoneum
 
(Av
 
Studies of the Intestine and Peritoneum in the Human Foetus 489
 
Part of lesser omnmum
 
,/I
 
Hepatic artery in fold of pernoneum
 
Pylurus
 
 
 
 
 
 
 
 
 
 
 
Inferior‘ area of
EHSWIC adhesion
 
/
 
/
I / Part of transverse
colon (cut,
 
iiT‘”’_‘D”°den0-_je_junal flexure
\\
 
‘.\
 
Mesentery of small intestine
(cut)
Aorta
’—i‘»é——|leo-colic artery(line root- folds
—7 —root of mesentery#)
 
.\ Parietal peritoneum with which the
 
mesentery of intestinal loop and the
genito-mesenteric fold eventually fuse
 
\
 
Genito-mesenteric fold (cut edge)
 
II! is a gemto-mesenteric-duodeno«rena| fold)
 
FIG. 1.—The arrangement of the peritoneum in relation to the duodenum of a full-time foetus is accurately
 
represented. The great oinentuni is not figured. The interrupted line indicates the extent of the retroduodenal fossa present between the head of the pancreas and the inferior vena cava. The line of the
aorta. marks its extent towards the left. The arrow indicates the orifice of the fossa. The peritoneum
of the intestinal loop has not fused down over the anterior surfaces of the filst, second, and third portions
of the duodenum. The sheet of peritoneum (A, A) is continued from it, however, over the anterior
surface of the seconul part of the duodenum, into the duoxleno-renal ligament and genito-mesenteric fold.
These sheets are all continuous. It, is noteworthy that the genito-mesenteric fold is attached to the
lowest part of the duodenum.
 
The fold which contains the hepatic artery, and which forms part of the septum bursarum omentalium,
represents (Swaen) meso-duodenum from which the duodenum has retracted. The upper free edge represents
the upper border of the meso-duodenum. “ Le transport de l’estomac, sa saillie si prononcéc dans la moitié
gauche dc la cavité abdominale, a entrainé dans cette direction la. premiere portion du duodenum qui l11i
fait suit, 1’a inclinée vers la gauche, l’a fait sortir du méso duodenum” (Swaen, p 164, Bibliographic
Anatormque, tome vii., 1899). The adhesion of the posterior surface of the duodenum (as well as that
of the stomach) to the transverse mesocolou is therefore, of course, secondary.
 
In this specimen the appendix and meso-appendix do not adhere to the genito-mesenteric fold. The
mesenteric border of the meso-appendix passes (along the line of a branch of the artery to the appendix)
towards the mesenteric border (the anterior part of which lies along the line of the ileac branch of the
ileo-colic artery) of the genito-mesenteric fold. but fails to reach it by a distance of 4 mm. (of. fig. 11).
 
Peritoneum of infest],-'3' loop
fused with mesoduodenum
490 Mr Douglas G. Reid
 
behind the head of the pancreas). I have found it, equal in depth to the
diameter of the fourth portion of the duodenum, in full—time foetuses; and
 
have noted similar, but usually rather shallow, intermediate retro—duodena1
fossee in adult bodies.


Hepatic artery m Ioldv


Part of lesser /
Synopsis of the Present Study - The retro-duodenal fossae are first considered; then the retro-pancreatico-duodenal recess; the development of the duodenum ; the relations of the peritoneum of the intestinal loop to the duodenum; the special relations of the duodenum; and the genesis of certain folds of peritoneum in relation to this part of the bowel. Lastly, I consider points of surgical interest in connexion with the natural subdivision of the abdominal cavity into compartments or recesses.
._;men1um


   
 
   


DUUW "‘0‘"°“3l — ‘~ . __ _ _ _ _ _ , ' . ; > , / Transverse mesoztolon
Preliminary Remarks - Cleland (see the Journal of Anatomy and Physiology, vols. i. and iii.) was chief amongst those who in this country advocated the displacement theory. He speaks of the duodenum “pushing its way underneath the peritoneum of the parieties”; for “ other viscera growing faster are thought to pull it (the meso-duodenum) away and appropriate it” (Brockway in Gray's Anatomy, 1897). He regards the left half of the transverse colon as being formed from “the terminal intestine” (the part of the large intestine which extends from the colon at the splenic flexure (see fig. 6) to the proctodaeum (Jonnesco) ). He states that, “as far as is at present known, the adhesion of serous surfaces only occurs as the result of pathological changes.
|.ganwnt ' "


(pull:-:1 upwards


At first, indeed, it may appear diflicult to see how, as first asserted by His and Toldt, the still mesial splenic flexure of an embryo 25 mm. long (see fig. 6) can gain the position it occupies in a foetus 37 mm. long (see fig. 8).‘ In this country the wheels of the displacement theory were still further sunk in the ruck by the writings of Bruce Young, Lockwood, Treves, and others.


V fi Rightfoldb0u11(hngU.-mce of fossa


Len fold l)<)umlu1)_; 0,-,y.(9 of {U553
Byron Robinson (Journal of Anatomy and Physiology, 1899, vol. xxxiii.) discusses the two “theories” (Toldt’s and other) without prejudice; and gradually British authors have been coming to regard the adhesion “theory” as the one which more probably expresses the truth.


/ Superior L,l|)O(lPl)£1l mm
I K <_#__,,, ‘L
\\ "  / / \ e T ,, ’——~— Inferior duodenan mm


' Left duodeno-parumal lold ‘JOHHESCOV
* 1 According to Flower (Medical Times and Gazette, 1872, vol. i.), the whole of the transverse colon is erived from the terminal intestine.


Inferior mesenteruc venn


(2)
Behind the head of the pancreas lies the fascia described by Treitz (see fig. 9).


Right duodeno~ Aorta
In front of the head of the pancreas there is also a layer of fascia described by Toldt (“the pre-pancreatic fascia ” of Fredet, see figs. 5, 9).
parietal fold of
Jonnesco


FIG. 2.—The four retro-duodenal fossae are shown. The duodenum is represented cut at its
No attempt has been made by those who advocate the displacement theory to account for these fascias.’ One can hardly doubt (see fig. 5) that they represent the meso-_duodenum. I have frequently demonstrated the fascia of Treitz. So compact a layer may it form in the adult as well as in the foetus, that it can readily be mistaken, at first, for normal endotheliumcovered peritoneum if the dissection to expose it has not been watched.


junction with the jejunum. The arrows indicate the orifices of the fossm (represented by
The prostato-peritoneal aponeurosis of Denonvilliersl also represents the connective element of peritoneum (cf. fig. 6 in Part IV. of my “Studies,” Journal of Anatomy and Physiology, vol. xlvii.).
interrupted lines and stippling). A


(1) The lower limit of the retro-pancreaticoeduodenal fossa (seen by me in a full-time foetus)
But if any doubt could be expressed, I have, apart from all this, given numerous illustrations of the_ truth of the statement" (which therefore ceases to express a “theory ”) that two nolrmal endothelial surfaces of peritoneum can adhere to one another.
whose entrance is at A.


(2) The lower limit, approximately, of the retro-duodenal fossa (seen by me in the adult)
Mall? states that it has been customary to call his second and third loops of small intestine (his third loop corresponds to loop A in fig. 6, the part there named “duodenum” being his first loop) the duodenum. “. . . more mature consideration of models convinced me that loops 2 and 3 are finally transferred to the left side of the body to form the upper part of the jejunum.”


whose orifice is at D; and the right limit of the retro-duonlenal fossa (seen by
How, then, is the mesentery at its root attached to the fourth (ascending) portion of the adult duodenum ?
J onnesco in the adult) whose orifice is at B.


(3) The lowe1' limit of the retro-duodenal fossa (seen by me in the adult) whose orifice is at
I have drawn attention to how certain folds of peritoneum may arise, and have pointed out the particular variations of the small and large intestine which result from displacement or from resistance to growth in certain directions.
E; and the lower limit of the retro-duodenal fossa (seen by me in the foetus, and
similar to the fossa I have met with in the adult) whose orifice is at D.


Direct adhesions of the duodenum to the parietal peritoneum may take
Treves has attempted to explain the origin of the inferior duodenal fold. His explanation involves the duodenum being “drawn between the layers of its own meso-duodenum.
the place of the duodenal folds and bound the orifice of the fossa.


Thus, in an adult (dissected at Cambridge, Lent Term, 1913), the whole
One must try, however, to determine how physical forces really do operate in the production of certain of the peritoneal folds; for even if this particular fold be present in “nearly all mammals,” it would, of course, be a complete mistake “to think that ‘heredity’ will build up organic beings without mechanical means.
of the posterior surface of the fourth part of the duodenum was free. A
Studies of the Intestine and Peritoneum in the Human Foetus 491


distinct retro—duodenal fossa in this case, however, only existed below (see
fig. 3). It extended towards the right nearly to the root of the ileo-colic
artery, and was bounded on the left by a direct adhesion of the duodenum
to the parietal peritoneum.


Again, the whole of the posterior surface of the fourth portion of the
* 1 “ En arriere de la prostate, entre les vésicules séminales et le rectum, existe une couche membraneuse bien distmcte, que j’appelle 1-ostato-péritonéale-—par son bord postérieur, elle adhere a cette portion du péritoine qui escend entre la vessie et le rectum” (Denou villiers, quoted by Proust, La Prostatectomie, p. 160).
duodenum may be found free from adhesions without the formation of any
* 2 The Johns Hopkins Hospital Bulletin, Nos. 90-91, September—October 1898.
fossa. Thus, in an adult, the fourth part of the duodenum, which was


04/ /__ Transverse colon
==The Retro-Duodenal Fossae==
' " ’ lDu||ed unwardsr


 
The retro-duodenal fossae which I shall now describe may be tabulated as follows : — (1) The retro—pancreatico-duodenal fossa. (2) The superior retro—duodenal fossa. (3) The intermediate, middle, or lateral retro-duodenal fossa. (4«) The inferior retro-duodenal fossa.‘


Fold of DEFIIOHQUYYI between
" ”’ duodeno-Jejunal flexure
and rnesocolon


———— Aorta
The Retro—panc'reatico—duodenal Fossa. — This fossa (see figs. 1, 2) was found by me in a full—time foetus. It is bounded in front by the first and second portions of the duodenum, and by the head of the pancreas; behind, by the parietal peritoneum in front of the inferior vena cava. On the right it is closed in by the duodeno-renal ligament and the genito—mesenteric fold. It extends towards the left as far as the aorta, and downwards as far as the upper border of the third part of the duodenum. It opens above into the vestibule of the lesser sac of peritoneum, and into the greater sac at the foramen of Winslow. It results from the conversion into a fossa of the retro-pancreatico-duodenal recess presently to be described.”


Adhesion
The Superior Retro-duodenal Fossa. — This fossa (see fig. 2) was found by me in an adult body dissected at Cambridge several years ago. It lay behind practically the Whole of the fourth portion of the duodenum. Its orifice, situated opposite the duodeno-jejunal flexure, was directed upwards and bounded on the sides by the free margins of two folds of peritoneum which passed from the parietal peritoneum and the mesocolon at its root. Its orifice thus rather resembles that of the duodeno-jej unal fossa described by Jonnesco in 1889, and situated “au niveau de 1’angle duodéno-jéjunal, entre son dos et la racine du mésocolon transverse.”


Disc between last lumbar
The Intermediate Retro-duodenal Fossa.—This fossa (see fig. 2) was found, well marked, by me in five out of twenty of the 12- to 22—cm. foetuses specially examined. It lies behind the fourth portion of the duodenum.
and first sacral vertebra


Fl-G. 3.——The arrow indicates the orifice of the fossa.
Its orifice, directed towards the left, is bounded above by the inferior mesenteric vein and the superior duodenal fold; below, by the inferior duodenal fold. The depth of the fossa may equal, but never exceeds, the diameter of the part of the duodenum to which it is related ('i.e. the fossa never passes behind the head of the pancreas). I have found it, equal in depth to the diameter of the fourth portion of the duodenum, in full—time foetuses; and have noted similar, but usually rather shallow, intermediate retro—duodenal fossee in adult bodies.


soldered down simply along its right border, could, to a certain extent, be
made to swing backwards and forwards as on a hinge.


When the posterior surface of the duodenum is free, jejunum may get
* 1 Discovered by J onnesco in 1893, and described by him as “ the retro-duodenal fossa.”
in behind it and place itself in contact with the head of the pancreas at
* 2 I have only recently begun to look for this fossa in the adult. It certainly appeared to have been present to a slight de ree in a body dissected at Cambridge, Lent Term, 1913. But, unfortunately, the dissectors Tied unconsciously enlarged it in a. downward direction before I saw the exact state of affairs.  
the left part of its circumference. This is seen in a 17-cm. foetus. Here
the jejunum descends from the duodeno-jejunal flexure and, at a peritoneal
fold resembling the inferior duodenal, makes a bend and passes upwards
behind the fourth part of the duodenum. Here it lies in contact with the
peritoneum covering the superior mesenteric artery and the left part of
the border of the head of the pancreas. It comes into contact with the
492 Mr Douglas G. Reid


inferior surface of the body of the pancreas, and forms a flexure in the
position normally occupied by the duodeno—_jejunal. It was firmly wedged
in between the duodenum and the pancreas, but did not adhere to either.
This is the nearest approach towards the development of a retroduodenal hernia that I have seen. A hernial sac might readily have been


- Part of ‘liver
'''Fig. 1.''' The arrangement of the peritoneum in relation to the duodenum of a full-time foetus is accurately represented. The great omentum is not figured. The interrupted line indicates the extent of the retroduodenal fossa present between the head of the pancreas and the inferior vena cava. The line of the aorta. marks its extent towards the left. The arrow indicates the orifice of the fossa. The peritoneum of the intestinal loop has not fused down over the anterior surfaces of the filst, second, and third portions of the duodenum. The sheet of peritoneum (A, A) is continued from it, however, over the anterior surface of the seconul part of the duodenum, into the duoxleno-renal ligament and genito-mesenteric fold. These sheets are all continuous. It, is noteworthy that the genito-mesenteric fold is attached to the lowest part of the duodenum.
/ Stomach (Cut across)
Mmasiemum  p _“ “‘ / /Zflody of pancreas
/ K (


LCSSQF ornentum
The fold which contains the hepatic artery, and which forms part of the septum bursarum omentalium, represents (Swaen) meso-duodenum from which the duodenum has retracted. The upper free edge represents the upper border of the meso-duodenum. “ Le transport de l’estomac, sa saillie si prononcéc dans la moitié gauche dc la cavité abdominale, a entrainé dans cette direction la. premiere portion du duodenum qui l11i fait suit, 1’a inclinée vers la gauche, l’a fait sortir du méso duodenum” (Swaen, p 164, Bibliographic Anatormque, tome vii., 1899). The adhesion of the posterior surface of the duodenum (as well as that of the stomach) to the transverse mesocolou is therefore, of course, secondary.


 
In this specimen the appendix and meso-appendix do not adhere to the genito-mesenteric fold. The mesenteric border of the meso-appendix passes (along the line of a branch of the artery to the appendix) towards the mesenteric border (the anterior part of which lies along the line of the ileac branch of the ileo-colic artery) of the genito-mesenteric fold. but fails to reach it by a distance of 4 mm. (of. fig. 11).
 
 
 


Pylorus T?


Head of pancreas\\


.Duodenum (second part)
'''Fig. 2.''' The four retro-duodenal fossae are shown. The duodenum is represented cut at its junction with the jejunum. The arrows indicate the orifices of the fossm (represented by interrupted lines and stippling).


Line above which
(1) The lower limit of the retro-pancreaticoeduodenal fossa (seen by me in a full-time foetus) whose entrance is at A.
duodenum is free


behind
(2) The lower limit, approximately, of the retro-duodenal fossa (seen by me in the adult) whose orifice is at D; and the right limit of the retro-duonlenal fossa (seen by J onnesco in the adult) whose orifice is at B.


Fold of peritoneum
(3) The lower limit of the retro-duodenal fossa (seen by me in the adult) whose orifice is at E; and the lower limit of the retro-duodenal fossa (seen by me in the foetus, and similar to the fossa I have met with in the adult) whose orifice is at D.


Parietal peritoneum


Genito-mesenterlc fold Part 0' mesemerv (Cut)


Ovary
Direct adhesions of the duodenum to the parietal peritoneum may take the place of the duodenal folds and bound the orifice of the fossa.


Thus, in an adult (dissected at Cambridge, Lent Term, 1913), the whole of the posterior surface of the fourth part of the duodenum was free. A distinct retro—duodenal fossa in this case, however, only existed below (see fig. 3). It extended towards the right nearly to the root of the ileo-colic artery, and was bounded on the left by a direct adhesion of the duodenum to the parietal peritoneum.


FIG. 4.——F(etus 17 cm. long. The jejunum immediately succeeding the duodenum passes downwards and then bends upwards behind the fourth portion of the duodenum. It comes into
contact with the inferior surface of the body of the pancreas, and here forms 9. flexure which
corresponds in position to the normal duodeno-jejunal flexure. The short descending part of
the jejunum adheres along its right border to the duodenum, and to the parietal peritoneum
down to the fold of peritoneum. Except for this, it is free, as is the rest of the jejunum.


formed by the secondary formation of peritoneal adhesions, pathological
Again, the whole of the posterior surface of the fourth portion of the duodenum may be found free from adhesions without the formation of any fossa. Thus, in an adult, the fourth part of the duodenum, which was soldered down simply along its right border, could, to a certain extent, be made to swing backwards and forwards as on a hinge.
or other.


I have noted apparent absence of the fourth part of the duodenum in
an adult.‘


1 I only saw this case, however, after the peritoneum had been subjected to some
handlin ; and, as the parts were unusually soft, it is possible that if the fourth portion of
the duo enuui had been unusually free it might have been dragged downwards. As in the
other case referred to, the disscctors were unconscious of having done any mischief.
Studies of the Intestine and Peritoneum in the Human F oetus 493


“ The Ret'r0—(lu00lenal Fossct” of J0'n/nesc0.‘—In View of the retroduodenal fossae which I have described, I propose to call this fossa the
inferior retro-duodenal fossa, a name which I understand has already been


suggested for it.
''Fig. 3.'' The arrow indicates the orifice of the fossa.
Any fossa in relation to the duodenum must, of course, be of interest


from a surgical point of view. “J’ajouterai seulement qu’elles out une
grand importance practique, car elles sont le siege le plus habituel des
hernies internes rétro-peritoneal dont j’ai pu réunir un nombre respectable


de cas (64.«).” 2
When the posterior surface of the duodenum is free, jejunum may get in behind it and place itself in contact with the head of the pancreas at the left part of its circumference. This is seen in a 17-cm. foetus. Here the jejunum descends from the duodeno-jejunal flexure and, at a peritoneal fold resembling the inferior duodenal, makes a bend and passes upwards behind the fourth part of the duodenum. Here it lies in contact with the peritoneum covering the superior mesenteric artery and the left part of the border of the head of the pancreas. It comes into contact with the inferior surface of the body of the pancreas, and forms a flexure in the position normally occupied by the duodeno—_jejunal. It was firmly wedged in between the duodenum and the pancreas, but did not adhere to either. This is the nearest approach towards the development of a retroduodenal hernia that I have seen. A hernial sac might readily have been formed by the secondary formation of peritoneal adhesions, pathological or other.


—— Diaphragm


UDIWV Dari inferior vena rave icup
surlacei


Llvvr Right 5llDV‘dI‘£’7lal b()dy ,9“,
'''Fig 4.''' Fetus 17 cm. long. The jejunum immediately succeeding the duodenum passes downwards and then bends upwards behind the fourth portion of the duodenum. It comes into contact with the inferior surface of the body of the pancreas, and here forms 9. flexure which corresponds in position to the normal duodeno-jejunal flexure. The short descending part of the jejunum adheres along its right border to the duodenum, and to the parietal peritoneum down to the fold of peritoneum. Except for this, it is free, as is the rest of the jejunum.


WU‘ 5‘”laCC’ Parietal peritoneum on trout ol


supra-renal body
I have noted apparent absence of the fourth part of the duodenum in an adult.‘
Caudate lobe and portion of Spigeliao


Duoclenurn (first part) — Head of pancreas lobe m recess
* 1 I only saw this case, however, after the peritoneum had been subjected to some handlin ; and, as the parts were unusually soft, it is possible that if the fourth portion of the duo enuui had been unusually free it might have been dragged downwards. As in the other case referred to, the disscctors were unconscious of having done any mischief.


Duodenum (third part, opposite disc
“ The Retro-duodenal Fossa” of Jonnesco.‘—In View of the retroduodenal fossae which I have described, I propose to call this fossa the inferior retro-duodenal fossa, a name which I understand has already been suggested for it. Any fossa in relation to the duodenum must, of course, be of interest


between first and
from a surgical point of view. “J’ajouterai seulement qu’elles out une grand importance practique, car elles sont le siege le plus habituel des hernies internes rétro-peritoneal dont j’ai pu réunir un nombre respectable


ril ‘ to
Colon la ‘pres Left root-told second lumbar vert)


duodenum)
Fig. 5. Longitudinal section (u. little to the right of the vertebral column) of a foetus 17 cm. long.
Flight kidney (cut abovei
Duct of the kidney
" The rnesentery
llmbilicus


Abdominal wall (a little to right
Note the recess, containing the caudate lobe (process), behind the pancreas, and the relations of the right suprarenal body.
of vertebrae;


==The Retro-Pancreatico-Duodenal Recess==


v I ’r\‘ Coils of small intestine
When well developed, this recess (see fig. 5) lies behind the first and second portions of the duodenum and the head of the pancreas in relation to these parts. It may descend almost to the third part of the duodenum. I first observed it, well marked, in a 17-cm. foetus (see fig. 5).
FIG. 5.—Longitudinal section (u. little to the right of the vertebral column) of a fcetus 17 cm. long.


Note the recess, containing the caudate lobe (process), behind the pancreas, and the relations of
1 This fossa ascends behinrl the fourth portion of the duodenum to the iluodeno-jejunal flexure. It is related to the third part of the duodenum to the (approximate) extent shown in fig. 2, and lies in front of the aorta. Its orifice looks downwar s.
the right suprarenal body.


THE RETRO-PANCREATICO-DUODENAL RECESS.
2 It is known that'bowel may protrude into the foran1en of Winslow. It is therefore possible that a piece of intestine could get into a persistent retro- ancrea.tico~duodenal recess or fossa. Inflammation might also extend to the up er part 0 the head of the pancreas should intlammator effusions, from the stomach or uodenum especially, collect in such a recess. One shoul also remember that “au niveau de la portion supérieure [of the duodenum] la circonférence [of the head of the pancreas] présente un prolongement tantét it peine indiqué, tantot assez développé pour (lepasser la face postérieure du duodenum; c’est le prolongement supérieur ou rét1'odu0dé-nal” (Charpy in Poirier’s Anatomy, 1905, vol. iv. p. 822).


When well developed, this recess (see fig. 5) lies behind the first and
second portions of the duodenum and the head of the pancreas in relation
to these parts. It may descend almost to the third part of the duodenum.
I first observed it, well marked, in a 17-cm. foetus (see fig. 5).


1 This fossa ascends behinrl the fourth portion of the duodenum to the iluodeno-jejunal
As in the 20-cm. foetus, a figure of which as seen in mesial section is given in Part IV. of my “Studies,” the pylorus, in this foetus, is placed opposite the disc between the eleventh and twelfth dorsal vertebrae; and the third portion of the duodenum, in the middle line, lies opposite the disc between the first and second lumbar vertebrae. The recess descends to a distance of 1 mm. from the third part of the duodenum.
flexure. It is related to the third part of the duodenum to the (approximate) extent shown
in fig. 2, and lies in front of the aorta. Its orifice looks downwar s.


2 It is known that'bowel may protrude into the foran1en of Winslow. It is therefore
Lying in this recess, between the duodenum and head of the pancreas in front and the inferior vena cava and the right suprarenal body behind, is a process of the caudate (Spigelian) lobe.
possible that a piece of intestine could get into a persistent retro- ancrea.tico~duodenal recess
or fossa. Inflammation might also extend to the up er part 0 the head of the pancreas
should intlammator effusions, from the stomach or uodenum especially, collect in such a
recess. One shoul also remember that “au niveau de la portion supérieure [of the
duodenum] la circonférence [of the head of the pancreas] présente un prolongement tantét
it peine indiqué, tantot assez développé pour (lepasser la face postérieure du duodenum;
c’est le prolongement supérieur ou rét1'odu0dé-nal” (Charpy in Poirier’s Anatomy, 1905,
vol. iv. p. 822).


VOL. XLVII. (THIRD SER. v01_.. V1lI.)—JULY 1913. 34
The anterior wall of the recess is of course continuous above with the postero—external surface of the fold which contains the hepatic artery. This fold represents a part of the meso—duodenum (see footnote, fig. 1).
494 Mr Douglas G. Reid


As in the 20-cm. foetus, a figure of which as seen in mesial section is
The retro-pancreatico—duodenal recess is also present, well marked, in an 11-cm. foetus. Here it descends behind the first part of the duodenum, and behind the upper half of the head of the pancreas and an exactly corresponding part of the second portion of the duodenum. Its posterior wall is formed by a small part of the right kidney in addition to the right suprarenal body and the inferior vena cava.
given in Part IV. of my “Studies,the pylorus, in this foetus, is placed
opposite the disc between the eleventh and twelfth dorsal vertebrae; and
the third portion of the duodenum, in the middle line, lies opposite the disc
between the first and second lumbar vertebrae. The recess descends to a
distance of 1 mm. from the third part of the duodenum.


Lying in this recess, between the duodenum and head of the pancreas
The recess is also seen in a 20-cm. foetus, but is related to the head of the pancreas only to a slight extent. I have since studied it in other foetuses.
in front and the inferior vena cava and the right suprarenal body behind,
is a process of the caudate (Spigelian) lobe.


The anterior wall of the recess is of course continuous above with
In many there is a recess lying simply behind the first portion of the duodenum without coming into direct relation with the head of the pancreas. But,I am inclined to think that the caudate lobe (prdcess) of the liver, as it lies in this recess, .comes into contact with the head of the pancreas more frequently than I at first thought. Unless a section be made, in a downward direction, through the first part of the duodenum and the head of the pancreas, the true relations of the recess may readily be overlooked.
the postero—external surface of the fold which contains the hepatic artery.
This fold represents a part of the meso—duodenum (see footnote, fig. 1).


The retro-pancreatico—duodenal recess is also present, well marked, in
In a full-time foetus there is a retro-pancreatico-duodenal recess which descends behind the first portion of the duodenum and the upper part of the head of the pancreas. It also descends, in front of the right suprarenal body, behind the second portion of the duodenum in its upper half. The caudate lobe of the liver, although coming into contact with the upper part of the head of the pancreas, does not descend to the bottom of the recess (of. fig. 5). The anterior and posterior walls of the lower part of the recess thus come into contact with one another.
an 11-cm. foetus. Here it descends behind the first part of the duodenum,
and behind the upper half of the head of the pancreas and an exactly
corresponding part of the second portion of the duodenum. Its posterior
wall is formed by a small part of the right kidney in addition to the right
suprarenal body and the inferior vena cava.


The recess is also seen in a 20-cm. foetus, but is related to the head
The retro-pancreatico-duodenal recess,‘ which should be looked for in the adult, is present in a 37-mm. foetus; and in it was lodged a portion of the liver. This I removed, exposing the smooth parietal peritoneum which forms the posterior wall of the recess.
of the pancreas only to a slight extent. I have since studied it in
other foetuses.


In many there is a recess lying simply behind the first portion of the
* 1 It is best to retain this name, even if the recess do not come into direct relation with the pancreas.  
duodenum without coming into direct relation with the head of the
pancreas. But,I am inclined to think that the caudate lobe (prdcess) of
the liver, as it lies in this recess, .comes into contact with the head of the
pancreas more frequently than I at first thought. Unless a section be
made, in a downward direction, through the first part of the duodenum
and the head of the pancreas, the true relations of the recess may readily
be overlooked.


In a full-time foetus there is a retro-pancreatico-duodenal recess which
descends behind the first portion of the duodenum and the upper part of
the head of the pancreas. It also descends, in front of the right suprarenal body, behind the second portion of the duodenum in its upper half.
The caudate lobe of the liver, although coming into contact with the upper
part of the head of the pancreas, does not descend to the bottom of the
recess (of. fig. 5). The anterior and posterior walls of the lower part of
the recess thus come into contact with one another.


The retro-pancreatico-duodenal recess,‘ which should be looked for in
In a 25-mm. embryo the duodenum forms a small loop which lies in a plane markedly transverse (see fig. 6). The liver lies in contact 'with the whole of the upper surface of this loop.
the adult, is present in a 37-mm. foetus; and in it was lodged a portion of


1 It is best to retain this name, even if the recess do not come into direct relation with
the pancreas.
Studies of the Intestine and Peritoneum in the Human F oetus 495


the liver. This I removed, exposing the smooth parietal peritoneum which
As the liver becomes relatively reduced in size the duodenum is pushed into a more frontal plane, and a definite recess is formed. This tends to become smaller and smaller, the meso—duodenum fusing with the parietal peritoneum from below upwards, until ultimately the peritoneum covering the posterior surfaces of the first and second portions of the duodenum and head of the pancreas may be completely soldered down. Should the second part of the duodenum alone become adherent to the parietal peritoneum, or to the left surface of the genito-mesenteric fold (see fig. 1), the retro—pancreatico—duodenal fossa is of course formed. Although the recess be present, the mesentery of the intestinal loop has already adhered to the anterior lamina of the meso—duodenum within the duodenal loop of the 37-mm. foetus (see fig. 8, “secondary root—area ”).
forms the posterior wall of the recess.
 
In a 25-mm. embryo the duodenum forms a small loop which lies in a
plane markedly transverse (see fig. 6). The liver lies in contact 'with the
whole of the upper surface of this loop.
 
As the liver becomes relatively reduced in size the duodenum is pushed
into a more frontal plane, and a definite recess is formed. This tends to
become smaller and smaller, the meso—duodenum fusing with the parietal
peritoneum from below upwards, until ultimately the peritoneum covering
the posterior surfaces of the first and second portions of the duodenum and
head of the pancreas may be completely soldered down. Should the
second part of the duodenum alone become adherent to the parietal
peritoneum, or to the left surface of the genito-mesenteric fold (see
fig. 1), the retro—pancreatico—duodenal fossa is of course formed. Although the recess be present, the mesentery of the intestinal loop has
already adhered to the anterior lamina of the meso—duodenum within the
duodenal loop of the 37-mm. foetus (see fig. 8, “secondary root—area ”).


In the 25-mm. embryo intestinal torsion is still incomplete (see fig. 6).
In the 25-mm. embryo intestinal torsion is still incomplete (see fig. 6).


In association with the recess in the larger foetuses, the colon, passing
In association with the recess in the larger foetuses, the colon, passing from the front of the right kidney, has to course markedly forwards upon the second portion of the duodenum to reach the first portion of the duodenum and the region of the pylorus (see fig. 5). All three structuresduodenum, pancreas, and transverse colon—are propped forwards, as it were, by the caudate lobe of the liver. The posterior surface of the head of the pancreas looks decidedly upwards as well as backwards (see fig. 5).
from the front of the right kidney, has to course markedly forwards upon
the second portion of the duodenum to reach the first portion of the
duodenum and the region of the pylorus (see fig. 5). All three structuresduodenum, pancreas, and transverse colon—are propped forwards, as it were,
by the caudate lobe of the liver. The posterior surface of the head of the
pancreas looks decidedly upwards as well as backwards (see fig. 5).


CHIEFLY CONCERNING THE DEVELOPMENT OF THE DUODENUM.
==Chiefly Concerning the Development of the Duodenum==


Mall has already drawn attention to the large size of the embryonic
Mall has already drawn attention to the large size of the embryonic duodenufn.
duodenufn.


In my 25-mm. embryo it is seen that the ornphalo-mesenteric vessels
In my 25-mm. embryo it is seen that the ornphalo-mesenteric vessels pass behind a portion of the alimentary canal (see fig. 6, “duodenum ") ; and one can have little doubt that this at least is part of the duodenum. From the point where these vessels come into this relation with the bowel, the intestine passes markedly backwards towards the posterior (dorsal) abdominal wall, and, bending inwards to some extent, comes into contact with the mesial mesentery at the neck of the intestinal loop. This inward bend is well shown in Mall’s fig. 10 of a 28-mm. foetus.
pass behind a portion of the alimentary canal (see fig. 6, “duodenum ") ; and
one can have little doubt that this at least is part of the duodenum. From
the point where these vessels come into this relation with the bowel, the
intestine passes markedly backwards towards the posterior (dorsal) abdominal wall, and, bending inwards to some extent, comes into contact
with the mesial mesentery at the neck of the intestinal loop. This inward
bend is well shown in Mall’s fig. 10 of a 28-mm. foetus.


The intestine now passes forwards and becomes continuous with Mall’s
The intestine now passes forwards and becomes continuous with Mall’s third loop (loop A in fig. 6).
third loop (loop A in fig. 6).


The part which thus passes forwards into A forms with the part that
The part which thus passes forwards into A forms with the part that passes backwards a loop, the convex surface of which looks backwards and also inwards (see “fig. 6); and at the summit of the curve the small intestine actually adheres, just abovethe splenic flexure, to the right surface of the mesial mesentery at the neck of the intestinal loop.‘
496 Mr Douglas G. Reid


Part of liver
(cut surface)—


   


Stomach xx‘ Lesser omemum
FIG. 6.-—-Embryo 25 mm. long dissected to show the intestinal loop. The head is represented more erect than is normal ; and the trunk has been somewhat straightened. Loop A overlaps the om halo-mesenteric vessels; and the parts of the small intestine in front of the knifeblade :3 so meet in front of these vessels. The omphalo-mesenteric vessels, which lie in a ridge of peritoneum, cross in front of loop D ; and this loop has a limb on each side of these vessels. The appendix is already distinguished by its small diameter. The splenic flexure lies immediately below the stomach in the middle line. The root of the mesentery of the terminal intestine is still mesial. There is no Meckel’s diverticulum. The anterior surface of the large stomach looks upwards as well as forwards Studies of the Intestine and Peritoneum in the Human Foetus 497


// Omphalo- mesenteric vessel
3


Duodenum ,‘ /— ,
It is jammed against this mesentery by the large liver. The part of the small intestine which extends backwards and inwards and is crossed by the vitelline vein is without doubt the duodenum. It is in the median line at its posterior extremity; and this is relatively fixed in position. Therefore, as the duodenum elongates, a more pronounced loop, concave towards the left, is formed.
/, “’ /Xsplemc flexure
 
Lateral wall of abdomen
 
D
 
~Omph31o_m .
Umbilical vessels ese"t°"° Vessels
 
Umbilical cord
 
FIG. 6.-—-Embryo 25 mm. long dissected to show the intestinal loop. The head is represented
more erect than is normal ; and the trunk has been somewhat straightened. Loop A overlaps
the om halo-mesenteric vessels; and the parts of the small intestine in front of the knifeblade :3 so meet in front of these vessels. The omphalo-mesenteric vessels, which lie in a
ridge of peritoneum, cross in front of loop D ; and this loop has a limb on each side of these
vessels. The appendix is already distinguished by its small diameter. The splenic flexure
lies immediately below the stomach in the middle line. The root of the mesentery of the
terminal intestine is still mesial. There is no Meckel’s diverticulum. The anterior surface
of the large stomach looks upwards as well as forwards
Studies of the Intestine and Peritoneum in the Human Foetus 497
 
passes backwards a loop, the convex surface of which looks backwards and
also inwards (see “fig. 6); and at the summit of the curve the small intestine
actually adheres, just abovethe splenic flexure, to the right surface of the
mesial mesentery at the neck of the intestinal loop.‘
 
It is jammed against this mesentery by the large liver. The part of
the small intestine which extends backwards and inwards and is crossed
by the vitelline vein is without doubt the duodenum. It is in the median
line at its posterior extremity; and this is relatively fixed in position.
Therefore, as the duodenum elongates, a more pronounced loop, concave
towards the left, is formed.


Already its first, second, and third parts are distinguishable.
Already its first, second, and third parts are distinguishable.


I have already noted that it lies, with part of the liver directly above
I have already noted that it lies, with part of the liver directly above it, in a plane which is markedly transverse (horizontal). The manner in which the retro-pancreatico-duodenal recess is definitely formed has also been indicated. .
it, in a plane which is markedly transverse (horizontal). The manner in
which the retro-pancreatico-duodenal recess is definitely formed has also
been indicated. .


But the fourth (ascending) portion of the duodenum has yet to be
But the fourth (ascending) portion of the duodenum has yet to be formed.
formed.


The small intestine now begins to work its way under the large, moving
The small intestine now begins to work its way under the large, moving about an axis which passes from the median posterior extremity of the duodenum to the caecum, still in the umbilical orifice of my 37-mm. foetus.
about an axis which passes from the median posterior extremity of the
duodenum to the caecum, still in the umbilical orifice of my 37-mm. foetus.


This movement has progressed to a considerable extent in this foetus
This movement has progressed to a considerable extent in this foetus
Line 663: Line 209:
‘ (see fig. 7).
‘ (see fig. 7).


The splenic flexure has now passed as far to the left as it can (see
The splenic flexure has now passed as far to the left as it can (see fig. 8). The left part of the transverse colon is now formed, and the terminal intestine passes downwards, and then downwards and inwards, skirting the right margin of the left testis (see fig. 7). The root of its mesentery is still mesial, however. ‘
fig. 8). The left part of the transverse colon is now formed, and the
terminal intestine passes downwards, and then downwards and inwards,
skirting the right margin of the left testis (see fig. 7). The root of its
mesentery is still mesial, however. ‘
 
The small intestine appears to have pressed the mesentery of the colic
portion of the intestinal loop upwards and backwards against the mesoduodenum, to the whole of which, within the concavity of the duodenal
loop, it now firmly adheres, although the serous surfaces of the duodenum
 
. are still free. Thus is formed the secondary root-area (see fig. 8).
 
In the full-time foetus (see fig. 1) the fusions of the peritoneum in
relation to the meso-duodenum have been arrested at a stage not much
more advanced than this. A genito-mesenteric fold has developed which
takes the place of the root of the mesentery and also anchors the duodenum.
 
The colon has gone on growing, and the caecum lies in the right iliac
 
1 Only the examination of more material can determine if this occur normally. Here,
again, there can be absolutely no doubt that two normal endothelial surfaces of peritoneum
had adhered to one another.
498 Mr Douglas G. Reid
 
fossa. The left part of the transverse colon is formed, and the root of its
mesentery is practically in the position it occupies in the adult.
 
The great omentum, adhering to the colon, helps to support this to the
right of the meso—duodenum (“secondary root-area ”).
 
In the 37-mm. foetus the upper part of the jejunum, having now worked


FIG. 7.—Foetus 37 mm. long, 6. The interrupted lines in A indicate the position of the lower
The small intestine appears to have pressed the mesentery of the colic portion of the intestinal loop upwards and backwards against the mesoduodenum, to the whole of which, within the concavity of the duodenal loop, it now firmly adheres, although the serous surfaces of the duodenum are still free. Thus is formed the secondary root-area (see fig. 8).
border of the liver and of the umbilical orifice. The upper border of the orifice lies 0 posite
the lower border of the liver. In B the interrupted line indicates the course of the (111 enum.
The parts of the intestine and mesentery which correspond are indicated by figures. The
stomach and first part of the colon (passing backwards from the umbilicus) lie in a more
horizontal plane than the figures appear to indicate. Normally, the testes and the descending
colon are in contact with, and completely concealed in front by, small intestine. But the
posterior abdominal wall has been straightened by traction exerted upon it through the hook,
and they are thus rendered visible.


its way to the left, is already directed upwards to form a short fourth
portion of the duodenum (see fig. 7). It is fused along its right border to
the peritoneum of the intestinal loop Where this adheres to the mesoduodenum along the inner part of the circumference of the head of the
Studies of the Intestine and Peritoneum in the Human Foetus 499


pancreas. Its mesenteric border now becomes the upper part of the root
In the full-time foetus (see fig. 1) the fusions of the peritoneum in relation to the meso-duodenum have been arrested at a stage not much more advanced than this. A genito-mesenteric fold has developed which takes the place of the root of the mesentery and also anchors the duodenum.
of the mesentery.


It is stated in Poirier’s Anatomy that the root of the mesentery upon the
The colon has gone on growing, and the caecum lies in the right iliac fossa. The left part of the transverse colon is formed, and the root of its mesentery is practically in the position it occupies in the adult.
fourth portion of the duodenum is something new, the result of a process
of adhesion of the peritoneum of the intestinal loop to the meso-duodenum
between the superior mesenteric artery and the duodeno—jejunal flexure.


But all the evidence I have is in favour of this part of the root of the


  N
* 1 Only the examination of more material can determine if this occur normally. Here, again, there can be absolutely no doubt that two normal endothelial surfaces of peritoneum had adhered to one another.


~—— %~ ——7 Mesogastnurn


The great omentum, adhering to the colon, helps to support this to the right of the meso—duodenum (“secondary root-area ”).
 
 
 
 


Coronary part 0'
In the 37-mm. foetus the upper part of the jejunum, having now worked its way to the left, is already directed upwards to form a short fourth portion of the duodenum (see fig. 7). It is fused along its right border to the peritoneum of the intestinal loop Where this adheres to the mesoduodenum along the inner part of the circumference of the head of the pancreas. Its mesenteric border now becomes the upper part of the root of the mesentery.
Septum hursarum omentalaum ————v


Superior omental recess


FIG. 7.—Foetus 37 mm. long, 6. The interrupted lines in A indicate the position of the lower border of the liver and of the umbilical orifice. The upper border of the orifice lies 0 posite the lower border of the liver. In B the interrupted line indicates the course of the (111 enum. The parts of the intestine and mesentery which correspond are indicated by figures. The stomach and first part of the colon (passing backwards from the umbilicus) lie in a more horizontal plane than the figures appear to indicate. Normally, the testes and the descending colon are in contact with, and completely concealed in front by, small intestine. But the posterior abdominal wall has been straightened by traction exerted upon it through the hook, and they are thus rendered visible.


Part of lesser omenmm _ ‘.


‘At Fold containing hepatic artery_, :V;‘‘‘,


- I
It is stated in Poirier’s Anatomy that the root of the mesentery upon the fourth portion of the duodenum is something new, the result of a process of adhesion of the peritoneum of the intestinal loop to the meso-duodenum between the superior mesenteric artery and the duodeno—jejunal flexure.
(p_art of mesoduodenum \Swa€'W /


Rooharea __ —/T
But all the evidence I have is in favour of this part of the root of the mesentery being simply the intestinal border of the mesentery of the small intestine. It has always been present.


\common for fold\,A and’ T  7* ——--~——Posterior or direct-lamina of


mesogastriumw d9V_e1qping great
Duodenumi _ ,7 , umentum
, ’ \V“ ’’’’ ” ’’Position of colon at splenic
/ e 1
’ - (1
Secondary root-area _,  exure
7-**'*T“““~'~4~— — Mesocolon
Co|on~ ___ /
//




‘I_ v ’  ————¥Srnall intestine
Fm. 8.—Dia.gram to illustrate the arrangement of the peritoneum in a. 37-mm. foetus. The ciecum is supposed to have been pulled from the umbilical orifice (in which it lay) towards the right. The posterior (direct) layer of the great omentum has been cut at its junction with the anterior (reflected) layer. The mesentery of the intestinal loop has fused to the mesoduodenum where this covers the head of the pancreas, and the “secondary root-area. "is thus formed. The anterior and posterior surfaces of the duodenum are still free; and the retropancreatico-duodenal space contains part of the liver. The roots of the meso-gastrium and meso-duodenum, and the root of the mesentery of the intestinal loop (secondary root-area) and that of the terminal intestine, are still practically in the middle line
/ (represented ns unusually
\ / attenuated)


Fm. 8.—Dia.gram to illustrate the arrangement of the peritoneum in a. 37-mm. foetus. The
ciecum is supposed to have been pulled from the umbilical orifice (in which it lay) towards
the right. The posterior (direct) layer of the great omentum has been cut at its junction with
the anterior (reflected) layer. The mesentery of the intestinal loop has fused to the mesoduodenum where this covers the head of the pancreas, and the “secondary root-area. "is thus
formed. The anterior and posterior surfaces of the duodenum are still free; and the retropancreatico-duodenal space contains part of the liver. The roots of the meso-gastrium and
meso-duodenum, and the root of the mesentery of the intestinal loop (secondary root-area) and
that of the terminal intestine, are still practically in the middle line


mesentery being simply the intestinal border of the mesentery of the small
This view of the origin of the fourth portion of the duodenum is further supported by the fact that the fossae which may lie behind this part never extend behind the head of the pancreas.
intestine. It has always been present.


This view of the origin of the fourth portion of the duodenum is further
The root of the mesentery is completed by the fusion, to the parietal peritoneum and to the duodenum, of the colic portion of the mesentery of 500 Mr Douglas G. Reid
supported by the fact that the fossae which may lie behind this part never
extend behind the head of the pancreas.


The root of the mesentery is completed by the fusion, to the parietal
the intestinal loop, downwards to the line of the ileo—colic vessels (see figs. 1, 4, 5, 9, 10).
peritoneum and to the duodenum, of the colic portion of the mesentery of
500 Mr Douglas G. Reid


the intestinal loop, downwards to the line of the ileo—colic vessels (see
A blood-vessel lying in a sheet of peritoneum forms a relatively rigid bar about which, as an axis, one part of the sheet may rotate towards another part.
figs. 1, 4, 5, 9, 10).


A blood-vessel lying in a sheet of peritoneum forms a relatively rigid
I have already shown that such a plication may determine the position of the arteries along the root of the pelvic mesocolon (see my “Studies,” Part II.).
bar about which, as an axis, one part of the sheet may rotate towards
another part.


I have already shown that such a plication may determine the position
In the same way, such a plication will determine the position of the ileo—colic vessels along the root of the mesentery, since the more passive colic part of the mesentery of the intestinal loop can, as a rule, solder to the posterior peritoneum downwards to the line of these vessels, about which the small intestinal part of the mesentery of the intestinal loop has rotated forwards, but no farther. The development of the genito-mesenteric fold, however, may cause a displacement of the root of the mesentery from this line (see my “Studies,” Part I.).
of the arteries along the root of the pelvic mesocolon (see my “Studies,”
Part II.).


In the same way, such a plication will determine the position of the
The intermediate retro-duodenal fossa would appear to result from the soldering down of the bowel which forms the fourth portion of the duodenum occurring first along the left aspect of the head "of the pancreas and the superior mesenteric artery, and in the region Where the inferior mesenteric vein may come into relation with the superior duodenal fold. If the adhesion extend towards the left, the fossa will become shallower, and may finally be obliterated.
ileo—colic vessels along the root of the mesentery, since the more passive
colic part of the mesentery of the intestinal loop can, as a rule, solder to
the posterior peritoneum downwards to the line of these vessels, about
which the small intestinal part of the mesentery of the intestinal loop has
rotated forwards, but no farther. The development of the genito-mesenteric
fold, however, may cause a displacement of the root of the mesentery from
this line (see my “Studies,” Part I.).


The intermediate retro-duodenal fossa would appear to result from the
The part of the bowel which is most fixed through its relations to other relatively immovable parts is the part which first tends to solder down.
soldering down of the bowel which forms the fourth portion of the
duodenum occurring first along the left aspect of the head "of the pancreas
and the superior mesenteric artery, and in the region Where the inferior
mesenteric vein may come into relation with the superior duodenal fold.
If the adhesion extend towards the left, the fossa will become shallower,
and may finally be obliterated.


The part of the bowel which is most fixed through its relations to other
==The Relations or the Peritoneum or the Intestinal Loop to the Duodenum==
relatively immovable parts is the part which first tends to solder down.‘


THE RELATIONS or THE PERITONEUM or THE INTESTINAL Loop
The colon usually lies parallel to the first portion of the duodenum. It lies along the lower border, or upon the anterior surface of this part (see figs. 5, 9).
TO THE DUODENUM.


The colon usually lies parallel to the first portion of the duodenum.
In five out of twenty foetuses (20 per cent. of cases) it forms a small loop (the right colic loop of J onnesco) as it lies opposite the duodenum.
It lies along the lower border, or upon the anterior surface of this part
(see figs. 5, 9).
 
In five out of twenty foetuses (20 per cent. of cases) it forms a small
loop (the right colic loop of J onnesco) as it lies opposite the duodenum.


There are two chief arrangements (see fig. 9).
There are two chief arrangements (see fig. 9).


(1) The peritoneum of the intestinal loop becomes adherent to the whole
(1) The peritoneum of the intestinal loop becomes adherent to the whole of the permanently anterior lamina of the meso-duodenum up to the lower border of the first part of the duodenum. At this level it bends downWards upon itself, so that the previously posterior surface of the colon becomes anterior, and a short transverse mesocolon persists which may subsequently disappear as the result of fusion (see fig. 9, A). This is the condition which is already present in my 37-mm. foetus (see fig. 8). The meso—gastrium and the transverse mesocolon are still quite free from one another, but almost meet at the level of the lower border of the first part of the duodenum. The lower part of the root of the meso-gastrium and the upper limit of the secondary root-area lie close together (closer than could well be indicated in the figure).
of the permanently anterior lamina of the meso-duodenum up to the lower


1 Jamming of viscera between relatively immovable parts may help to determine adhesion. Thus in four out of thirteen specimens the left extremity of the transverse colon is
jammed between the ancreas and the spleen, and adheres, as in the adult, to the inferior
surface of the body 0 the pancreas. In the other nine cases, althou h the colon is in contact with the body of the pancreas, there is no such jamming, an a fissure, the walls of
which are lined by the meso-gastrium, intervenes between the colon and the pancreas.
Studies of the Intestine and Peritoneum in the Human Foetus 501


border of the first part of the duodenum. At this level it bends downWards upon itself, so that the previously posterior surface of the colon
becomes anterior, and a short transverse mesocolon persists which may
subsequently disappear as the result of fusion (see fig. 9, A). This is
the condition which is already present in my 37-mm. foetus (see fig. 8).
The meso—gastrium and the transverse mesocolon are still quite free from
one another, but almost meet at the level of the lower border of the first
part of the duodenum. The lower part of the root of the meso-gastrium


Rlghl omental process
* 1 Jamming of viscera between relatively immovable parts may help to determine adhesion. Thus in four out of thirteen specimens the left extremity of the transverse colon is jammed between the ancreas and the spleen, and adheres, as in the adult, to the inferior surface of the body 0 the pancreas. In the other nine cases, althou h the colon is in contact with the body of the pancreas, there is no such jamming, an a fissure, the walls of which are lined by the meso-gastrium, intervenes between the colon and the pancreas.


   
 


 
FIG. 9.—Diagram to show the arrangement of the peritoneum opposite the duodenum. The angle marked + may disappear through fusion. In the left root-fold are lodged the ileo-colic artery and vein, nerve filaments, and a number of lymphatic nodes. This fold is described in Part II. of my “ Studies.”


Parietal t e m\__ /
F79“ 0" L‘ _,, _____7‘‘‘ lg ‘_ Parietal pernoneum
Duogenum mpg; pa,-p—“___R R4 “RE " x.\ Recess
‘ l J:  ~‘li 7* Duodenum lfirsl Par“


Right ornental DrOCe$::__ - -:3 /9 ,}
(2) There is the same disposition without the persistence of a mesocolon (see fig. 9, B).


Tilly’ I xx ‘\ li\~  ., Adheslons
It has been noted in Part III. of my “Studies” that, after an arrangement has been acquired as described under (1), a secondary movement may occur of the transverse colon towards the left and headwards.


/ + ‘L
The colon and peritoneum of the intestinal loop always completely cover the meso-duodenum below and to the right of the pylorus.


Transverse colon To 1
In the 25—mm. embryo the meso-gastrium is free exactly to the extent indicated in fig. 8 for the 37-mm. foetus, but has not begun to project downwards beyond the stomach as in that foetus. Later it will fuse with the transverse mesocolon and colon, and still later the right omental process appears. When this develops, it extends, therefore, over the peritoneum of the intestinal loop, and not overvthe meso-duodenum such as is figured and described in the classics (see also fig. 10).
'7, "fMesoduodenum (fascias of
' Treatz and Fredetl


- :«~«,4


\ j [2
Head of pancreas ——~r* W4“ ‘


~—r Duodenum (third part)


K ' ‘lleo-colic vein
Fig. 10. 10.-—Foetus 127 cm. long. The peritoneum between the duodenum and the transverse colon belongs to the mesentery of the intestinal loop, and is not meso-duodenum. Therefore in this foetus had the right omental process developed later, it would have extended over peritoneum of the intestinal loop, not over meso-duodenum such as is figured and described in the classics (e.g. Poirier’s Anatomy). In all the other fcetuses the mesu-duodenum to the right of and below the pylorus is completely covered by the transverse colon and the mesentery of the intestinal loop (see fig. 9). The figures and descriptions given in the books dealing with the development of the peritoneum are inaccurate in this respect. The terminal intestine forms a loop which lies in the right iliac fossa.


==The Special Relations of the Duodenum==


lleo-colic artery
(1) The caudate lobe (process) of the liver may lie directly behind the first and second portions of the duodenum, as has already been described. (2) The right suprarenal body may descend behind the duodenum to a marked extent (see fig. 5) ; and even when the caudate lobe lay in front of it to ‘the extent shown in fig. 5, it came into direct relation, below the liver, with the lower end of the second portion of the duodenum. When there is no marked recess it also comes into direct relation with the duodenum at the angle between its first and second parts. Indeed, it often descends behind the second portion to_the upper part of the junction of this with the third portion.


Mesentery of Small mtestine  l
/' V‘; [2


K‘-+7:/l
In the full-time foetus mentioned it lay behind the upper half of the second part of the duodenum. It may also come into _contact with the head of the pancreas (of. fig. 5) to the right side of the inferior vena cava. The left suprarenal body is an immediate relation of the duodenum at the duodeno-jejunal flexure.


. / l


/ l
(3) The genito-mesenteric fold gains an attachment to the duodenum (see fig. 1). The suspensory muscle of Treitz} “as Professor Cleland is in the habit of pointing out in his lectures, seems to have more importance than is usually attributed to it. . . . The duodenum may curve downwards even as far as the right iliac fossa,2 and yet its junction with the jejunum is always on the left side of the superior mesenteric artery, beneath the transverse mesocolon, owing to the suspension of this part of the small intestine by the musculus suspensorius duodeni.” This muscle undoubtedly tends to become hypertrophied when the duodenum is unusually free (see my paper “Imperfect Torsion of the Intestinal Loop,” Journal of Anatomy and Physiology, vol. xlii.).


/ ll "// ‘/ mm7"""‘l ' ” ” Pelvic colon


But I have pointed out another probable cause of downward displacement of the duodenum. This is the traction which may apparently be exerted upon the duodenum at the junction of its second and third parts by the genito-mesenteric fold.


Loop of pelvnc co|on'""" =’ ’


Small unteshne —\__
In an adult the duodenum, at this junction, descended to the level of the disc between the last lumbar and first sacral vertebrae (see fig. 3). This was most probably due to the unusually large cirrhotic liver.


7. I ll
/
l ll .—4 — »————~——T *' Small intestine
; , l


l l
Nevertheless, the genito-mesenteric fold should be kept in mind as another probable cause of some degree of downward displacement of the duodenum (see also footnote, fig. 1).


1 l


l
(4) The left root-fold lies in the foetus in front of the fourth portion of the duodenum, along the line of the root of the mesentery passing outwards towards the caecum (see figs. 4-, 5, 9, 10).


4‘.
* 1 A good figure of this muscle is given in Spalteholz’s Atlas (fig. 633). 2 It is interesting to note all the abnormal contents of this fossa—duodenum, trans verse colon, pelvic colon, liver, lower extremity of right kidney, testis of adult, etc. See also fig. 10. 504 Mr Douglas G. Reid


\
\.,


A B
(5) The pelvic colon may ascend to the duodenum, and may also be distinctly overlapped by the left root—fold.1


FIG. 9.—Dia.gram to show the arrangement of the peritoneum opposite the duodenum. The
==The Genesis of Certain Folds of Peritoneum in Relation to the Duodenum==
angle marked + may disappear through fusion.
In the left root-fold are lodged the ileo-colic artery and vein, nerve filaments, and a number
of lymphatic nodes. This fold is described in Part II. of my “ Studies.”


and the upper limit of the secondary root-area lie close together (closer
I have already shown (“ Studies,” Part III.) that if the “bloodless” fold of Treves adhere to the abdominal wall, it may become enormous through stretching during the descent of the caecum. I have also shown that folds may be present at the periphery of “the superior area of gastric adhesion” (“bare area”). A distinct fold may also be seen sometimes at the lower limit of the adhesions which bind the ascending colon to the parietal peritoneum.
than could well be indicated in the figure).


(2) There is the same disposition without the persistence of a mesocolon
(see fig. 9, B).


It has been noted in Part III. of my “Studies” that, after an arrangement has been acquired as described under (1), a secondary movement may
In fig. 4 a fold is illustrated which lies at a bend of the bowel, and at the lower limit of the adhesions fixing down a part of the jejunum. It is very similar in appearance to the inferior duodenal fold which is present, as is also the superior, in a number of my 12 to 22-cm. foetuses.
occur of the transverse colon towards the left and headwards.


The colon and peritoneum of the intestinal loop always completely cover
Folds (see figs. 2, 3) may also be seen at the duodeno—_jejunal flexure connecting the bowel at this point with the transverse mesocolon.
the meso-duodenum below and to the right of the pylorus.
502 Mr Douglas G. Reid
 
In the 25—mm. embryo the meso-gastrium is free exactly to the extent
indicated in fig. 8 for the 37-mm. foetus, but has not begun to project
downwards beyond the stomach as in that foetus. Later it will fuse with
the transverse mesocolon and colon, and still later the right omental
process appears. When this develops, it extends, therefore, over the peritoneum of the intestinal loop, and not overvthe meso-duodenum such as
is figured and described in the classics (see also fig. 10).
 
1
 
i Abdominal wall (cm)
 
 
 
 
Liver (cut surface)— Pre sple _ f Id
- me o
 
Posterior portion of ‘V  i
 
q ad t lobe Spleen (diaphragmatic
U ra 8
 
surface)
 
Gall-bladder “
‘ l
 
 
 
Pylorusf  ‘
Single root,-fold
 
- Great omentum
lleum
 
Cxecum
 
‘  Co|on
 
F 10. 10.-—Foetus 127 cm. long. The peritoneum between the duodenum and the transverse colon
belongs to the mesentery of the intestinal loop, and is not meso-duodenum. Therefore in this
foetus had the right omental process developed later, it would have extended over peritoneum
of the intestinal loop, not over meso-duodenum such as is figured and described in the classics
(e.g. Poirier’s Anatomy). In all the other fcetuses the mesu-duodenum to the right of and
below the pylorus is completely covered by the transverse colon and the mesentery of the
intestinal loop (see fig. 9). The figures and descriptions given in the books dealing with the
development of the peritoneum are inaccurate in this respect. The terminal intestine forms a
loop which lies in the right iliac fossa.
 
THE SPECIAL RELATIONS or THE DUODENUM.
 
(1) The caudate lobe (process) of the liver may lie directly behind
the first and second portions of the duodenum, as has already been
 
described.
(2) The right suprarenal body may descend behind the duodenum to a
Studies of the Intestine and Peritoneum in the Human Foetus 503
 
marked extent (see fig. 5) ; and even when the caudate lobe lay in front of
it to ‘the extent shown in fig. 5, it came into direct relation, below the liver,
 
with the lower end of the second portion of the duodenum. When there_
 
is no marked recess it also comes into direct relation with the duodenum
at the angle between its first and second parts. Indeed, it often descends
behind the second portion to_the upper part of the junction of this with
the third portion.
 
In the full-time foetus mentioned it lay behind the upper half of the
second part of the duodenum. It may also come into _contact with the
head of the pancreas (of. fig. 5) to the right side of the inferior vena cava.
The left suprarenal body is an immediate relation of the duodenum at the
duodeno-jejunal flexure.
 
(3) The genito-mesenteric fold gains an attachment to the duodenum
(see fig. 1). The suspensory muscle of Treitz} “as Professor Cleland is
in the habit of pointing out in his lectures, seems to have more importance than is usually attributed to it. . . . The duodenum may
curve downwards even as far as the right iliac fossa,2 and yet its
junction with the jejunum is always on the left side of the superior
mesenteric artery, beneath the transverse mesocolon, owing to the
suspension of this part of the small intestine by the musculus suspensorius duodeni.” This muscle undoubtedly tends to become hypertrophied when the duodenum is unusually free (see my paper “Imperfect
Torsion of the Intestinal Loop,” Journal of Anatomy and Physiology,
vol. xlii.).
 
But I have pointed out another probable cause of downward displacement of the duodenum. This is the traction which may apparently be
exerted upon the duodenum at the junction of its second and third parts
by the genito-mesenteric fold.
 
In an adult the duodenum, at this junction, descended to the level of
the disc between the last lumbar and first sacral vertebrae (see fig. 3).
This was most probably due to the unusually large cirrhotic liver.
 
Nevertheless, the genito-mesenteric fold should be kept in mind as
another probable cause of some degree of downward displacement of the
duodenum (see also footnote, fig. 1).
 
(4) The left root-fold lies in the foetus in front of the fourth portion of
the duodenum, along the line of the root of the mesentery passing outwards
towards the caecum (see figs. 4-, 5, 9, 10).
 
1 A good figure of this muscle is given in Spalteholz’s Atlas (fig. 633).
2 It is interesting to note all the abnormal contents of this fossa—duodenum, trans
verse colon, pelvic colon, liver, lower extremity of right kidney, testis of adult, etc.
See also fig. 10.
504 Mr Douglas G. Reid
 
(5) The pelvic colon may ascend to the duodenum, and may also be
distinctly overlapped by the left root—fold.1
 
THE GENESIS or CERTAIN FoLns or PERITONEUM IN RELATION
' TO THE DUODENUM.
 
I have already shown (“ Studies,” Part III.) that if the “bloodless” fold
of Treves adhere to the abdominal wall, it may become enormous through
stretching during the descent of the caecum. I have also shown that folds
may be present at the periphery of “the superior area of gastric adhesion”
(“bare area”). A distinct fold may also be seen sometimes at the lower
limit of the adhesions which bind the ascending colon to the parietal
peritoneum.
 
In fig. 4 a fold is illustrated which lies at a bend of the bowel, and at
the lower limit of the adhesions fixing down a part of the jejunum. It is
very similar in appearance to the inferior duodenal fold which is present,
as is also the superior, in a number of my 12 to 22-cm. foetuses.
 
Folds (see figs. 2, 3) may also be seen at the duodeno—_jejunal flexure
connecting the bowel at this point with the transverse mesocolon.


At these points the connective elements of two originally distinct peritoneal sheets have, of course, become continuous with one another.
At these points the connective elements of two originally distinct peritoneal sheets have, of course, become continuous with one another.


Just as in the case of the “ bloodless” fold, traction upon these
Just as in the case of the “ bloodless” fold, traction upon these connective elements, where they are continuous, will naturally tend to elongate them into a fold, provided the area of adhesion be not too diffuse. This will tend to occur most where stress is greatest, eg. at the duodeno-jejunal flexure.
connective elements, where they are continuous, will naturally tend to
elongate them into a fold, provided the area of adhesion be not too diffuse.
This will tend to occur most where stress is greatest, eg. at the duodeno—
_je_junal flexure.


At this flexure there is not only the traction exerted directly upon the
At this flexure there is not only the traction exerted directly upon the adhering connective elements by the jejunum itself, but the stomach presses downwards upon the bowel, and the upper horizontal coils of small intestine press upon it from left to right. Stress also concentrates itself upon the duodenum at the angle between its third and fourth portions. Here there is the pressure exerted upon it from left to right by the upper horizontal coils, and from below by the vertical coils of small intestine.
adhering connective elements by the jejunum itself, but the stomach presses
downwards upon the bowel, and the upper horizontal coils of small intestine
press upon it from left to right. Stress also concentrates itself upon the
duodenum at the angle between its third and fourth portions. Here there
is the pressure exerted upon it from left to right by the upper horizontal
coils, and from below by the vertical coils of small intestine.


Through traction upon the connective element of the outer coat» of the
Through traction upon the connective element of the outer coat» of the bowel some muscle fibres of the gut may also be drawn, as it were, into a peritoneal fold (see my paper on “The Caeco—appendicular Fold,” Journal of Anatomy and Physiology, vol. xlvi.).
bowel some muscle fibres of the gut may also be drawn, as it were, into a


1 Should adhesions develop between the upper part of an omega loop of pelvic colon
and the third part of the duodenum and adjoining mesentery and parietal peritoneum, the
pelvic colon may remain permanently fixed in the abdominal cavity. I have recently seen
this condition, due to strong adhesions, in two adult bodies otherwise normal as regards
peritoneal adhesions. Apart from the question of this impairing the functional activity of
the bowel, it is possible that in such cases dificulties might arise in an attempt to pull
downwards the right limb of the omega loop in the operation of excision of the rectum by
the sacral route where the growth is found to extend far upwards.
Studies of the Intestine and Peritoneum in the Human Foetus 505


peritoneal fold (see my paper on “The Caeco—appendicular Fold,” Journal of
* 1 Should adhesions develop between the upper part of an omega loop of pelvic colon and the third part of the duodenum and adjoining mesentery and parietal peritoneum, the pelvic colon may remain permanently fixed in the abdominal cavity. I have recently seen this condition, due to strong adhesions, in two adult bodies otherwise normal as regards peritoneal adhesions. Apart from the question of this impairing the functional activity of the bowel, it is possible that in such cases dificulties might arise in an attempt to pull downwards the right limb of the omega loop in the operation of excision of the rectum by the sacral route where the growth is found to extend far upwards.  
Anatomy and Physiology, vol. xlvi.).


Traction or pressure exerted upon peritoneum on each side of a bloodvessel may also, in some "cases, produce a vascular fold. I have described
such a fold in connection with the genito—mesenteric fold (“ Studies,” Part I.,
Journal of Anatomy and Physiology, vol. xlv.).


This idea is further illustrated in an 18—c1n. foetus. Here the upper
Traction or pressure exerted upon peritoneum on each side of a bloodvessel may also, in some "cases, produce a vascular fold. I have described such a fold in connection with the genito—mesenteric fold (“ Studies,” Part I., Journal of Anatomy and Physiology, vol. xlv.).
part of the inferior mesenteric vein, taking its usual arched course, lay,
above a point indicated by + in fig. 2, along the free margin of a fold of
peritoneum which formed the anterior wall of a fossa 2'5 mm. deep. The
left border of the fourth portion of the duodenum, up to the duodenojejunal flexure, was lodged in this fossa, but did not adhere to the fold.
Had the duodenum adhered to the upper half of the fold, quite a typical
superior duodenal fold, containing’ the inferior mesenteric Vein, and fossa
would have been formed. V


Thus, if, as in this case, the fourth part of the duodenum, being
practically fixed below, whilst at the duodeno—_jejunal flexure it is in
contact with the pancreas and adheres to some extent to the transverse
mesocolon, remain free behind, it may, during growth, find space for itself
by burrowing its way, as it were, under the vein.


These views, of course, do not imply that endothelium is dragged
This idea is further illustrated in an 18—c1n. foetus. Here the upper part of the inferior mesenteric vein, taking its usual arched course, lay, above a point indicated by + in fig. 2, along the free margin of a fold of peritoneum which formed the anterior wall of a fossa 2'5 mm. deep. The left border of the fourth portion of the duodenum, up to the duodenojejunal flexure, was lodged in this fossa, but did not adhere to the fold. Had the duodenum adhered to the upper half of the fold, quite a typical superior duodenal fold, containing’ the inferior mesenteric Vein, and fossa would have been formed. V
off some other part in order to coat the fold which is produced. In some
cases such a fold may disappear later through fusion with adjacent
peritoneum.


The cystocolic ligament is present in 30 per cent. of foetuses. I have
included in this some cases in which the colon adheres directly to the
body of the gall-bladder. In the two cases I have mentioned_in which
there is a well-marked retro-pancreatico-duodenal recess the colon and
duodenum, adhering together, are propped forwards, as it Were, by the
caudate-lobe of the liver lying in this recess (see fig. 5); and both adhere
directly to the body of the gall-bladder at the angle between the first and
second parts of the duodenum. The endothelial surfaces, thus brought
together, are directly continuous with those of the lesser omentum.


Thus we have the birth of What obviously could become later a definite
Thus, if, as in this case, the fourth part of the duodenum, being practically fixed below, whilst at the duodeno—_jejunal flexure it is in contact with the pancreas and adheres to some extent to the transverse mesocolon, remain free behind, it may, during growth, find space for itself by burrowing its way, as it were, under the vein.
cystocolic fold continuous with the lesser omentum, and passing over the
duodenum, to the colon. I have indicated in Part III. of my “Studies”


that a direct adhesion of the colon to the lesser omentum may sometimes
These views, of course, do not imply that endothelium is dragged off some other part in order to coat the fold which is produced. In some cases such a fold may disappear later through fusion with adjacent peritoneum.


also give rise to this ligament.
The cystocolic ligament is present in 30 per cent. of foetuses. I have included in this some cases in which the colon adheres directly to the body of the gall-bladder. In the two cases I have mentioned_in which there is a well-marked retro-pancreatico-duodenal recess the colon and duodenum, adhering together, are propped forwards, as it Were, by the caudate-lobe of the liver lying in this recess (see fig. 5); and both adhere directly to the body of the gall-bladder at the angle between the first and second parts of the duodenum. The endothelial surfaces, thus brought together, are directly continuous with those of the lesser omentum.


Peritoneal bands consequent upon inflammation may also, of course,
Thus we have the birth of What obviously could become later a definite cystocolic fold continuous with the lesser omentum, and passing over the duodenum, to the colon. I have indicated in Part III. of my “Studies” that a direct adhesion of the colon to the lesser omentum may sometimes also give rise to this ligament.
arise through direct adhesions and subsequent elongation the result of
traction.
506 Mr Douglas G. Reid


THE SUBDIVISION or THE ABDOMINAL CAVITY BY PERITONEAL
Peritoneal bands consequent upon inflammation may also, of course, arise through direct adhesions and subsequent elongation the result of traction.  
FoLDs AND ADHESIONS.


A. Subd/ivisions of the Greater Sac of Pe'm'tonewm.—(1) In two adult
==The Subdivision of the Abdominal Cavity by Peritoneal Folds and Adhesions==
bodies dissected at Cambridge, Lent Term, 1913, I found the great omentuin
adhering to the anterior abdominal wall along an uninterrupted line from


Diaphrfigm
===A. Subdivisions of the Greater Sac of Peritoneum===


Compartment of lesser sac of
(1) In two adult bodies dissected at Cambridge, Lent Term, 1913, I found the great omentuin adhering to the anterior abdominal wall along an uninterrupted line from a point a little to the right of the middle line outwards to the right abdominal wall (see fig. 11). Thus a compartment was formed between the transverse colon and great omentum below and the visceral surface of the liver above.
peritoneum for Spvgelian lobe


_¥« Body wall


J


 
Fig. 11. This figure, constructed from three specimens (two adults and a foetus) examined by me in the Cambridge dissecting-room, Lent Term, 1913, illustrates the subdivision, more or less complete, of the abdominal cavity by peritoneal folds and adhesions. A and B indicate the two compartments of the lesser sac (represented by an interrupted line) resulting from the continuity of the superior and inferior areas of gastric adhesion. D and 0 indicate the compartments formed through an adhesion, in both adults, of the great omentum to the anterior and right abdominal walls. E and F are the compartments, below the mesentery, to the right and left of the genito-mesenteric fold. The pelvic colon (the M-shaped form was resent. well marked, in one of the adults) occupies compartment F; the caecum and appen ix, and part of the ileum, occupy compartment E. S indicates the compartment for the spleen. It is closed in front and below by the splenic process of peritoneum. M and N are the compartments on each side of the falciform ligament.
 
 
 


/.


Falciform ligament ——4
Inflammatory effusions from the stomach, liver, or gall-bladder would‘ readily have collected in it; and it would have formed an important barrier in restricting their spread into the general peritoneal cavity. It formed, as it were, a ready-made abscess cavity (see fig. 11, D) shutting off the right portion of the recess, between the liver and the transverse colon and mesocolon, to which the name of the hepato—c0lic recess may be given.
I! V’ "


Pre-splenic (old — adheres to


Septum formed by gastric adhesions ,
(2) The pre-splenic fold of the splenic process of peritoneum is present normally in the adult. The sub-splenic part of this process is also sometimes seen as a distinct fold in the adult.‘ When fully developed it adheres to the diaphragm; and in several adults I have noted that, as the presplenic fold lies between the spleen and the diaphragm, it adhered to the diaphragm, as well as to the diaphragmatic surface of the spleen. Thus the spleen comes to lie in a definite compartment,closed in front and below by the splenic process. This compartment may be termed the splenic compartment or recess (see fig. 11, S).
Spleen and diaphragm


‘ I
Foramen of Winslow-——r— i/’’”“'''


(l _ .
(3) The space beneath the transverse colon and mesocolon to the left of the duodeno-jejunal flexure, and below the root of the mesentery, may be termed the sub-mesenteric recess. The genito-mesenteric fold, when present, divides this into right and left sub-mesenteric recesses (see fig. 11, E, F).
ll  ‘ ‘«— , Phreno-co|ic ligament of Toldt
Lower border oi liver ‘ I V


Adhesion of SW8‘ 0"“‘-"‘lU'“ ‘O


y ; Transverse mesocolon
The caecum2 and appendix lie in the right recess; the pelvic colon lies in the left.
anterior abdominal wall , M
( ,


'—- Mesentery (cm edge)
In some cases, as in one which I record in another paper, it would appear to be best to cut through the left (genito-mesenteric) wall (to which the appendix and meso—appendix adhere) of the right sub-mesenteric recess in order to reach the appendix. If this can be done, considerable tearing and rough usage of the peritoneum by the surgeon would be avoided. The small intestine should first be pulled forwards. The genito—mesenteric fold isthus exposed.
Lett or Superior root-fold


Outline of lesser sac of
* 1 Since describing it I have seen the sub-splenic fold, distinct and well marked, in two adults. In both it adhered to the diaphragm and formed the suspensory ligament of the spleen. In one it co-existed with the phreno-colic-ligament of Tol t ; in the other, Toldt’s ligament had not developed.
* 2 It is, of course, important to remember that, in the adult, the caocum may he found lying in the central region of the abdomen at any point between the umbilicus (at which it lies in my 37-mm. foetus) and pelvic cavity, into which it may also descend.


Ascending co|on— - — — pe"'°"e“'"


Appe”dlX eDlDl0'C£I arising
In the right lateral region I found the caccum of an adult wedged between the liver and the diaphragm. Engel has noted a similar case. In this region it may also lie at any level below the liver In my 12- to 22-cm. fwtuses it lies in front of the right kidney, or immediately below it. In this latter situation the appendix is usually in a retro-colic plane, and, as a rule, after ascending to the kidney is bent downwards and thus accommodates itself to the space available between the kidney and the parietal peritoneum below this prominent organ.


from p21rieto.C0[,Cfold‘**—" -; M'5h3D8d Delwc Colon


lsenn often H1 fqgtusv occa5,0,‘a||y
If the lower part of the ascending colon be free, the caccum may be pushed upwards by coils of small intestine, but yet could be pulled downwards by the surgeon (see my paper in the Journal of Anatomy and Physiology, vol. xlvi. p. 239).


Gemlo-mesenteric fold In adult’


Appendix adhering to
The ceccum has also been found lying in the left iliac fossa. “Remarquons—que le czecum peut faire partie de toute les hernies ombilicale, crurale, inguinale, et meme du cote gauche.”
right side of genito~
mesenteric (old


F IG. 11.—This figure, constructed from three specimens (two adults and a foetus) examined by me
in the Cambridge dissecting-room, Lent Term, 1913, illustrates the subdivision, more or less
complete, of the abdominal cavity by peritoneal folds and adhesions. A and B indicate the
two compartments of the lesser sac (represented by an interrupted line) resulting from the
continuity of the superior and inferior areas of gastric adhesion. D and 0 indicate the compartments formed through an adhesion, in both adults, of the great omentum to the anterior
and right abdominal walls. E and F are the compartments, below the mesentery, to the right
and left of the genito-mesenteric fold. The pelvic colon (the M-shaped form was resent.
well marked, in one of the adults) occupies compartment F; the caecum and appen ix, and
part of the ileum, occupy compartment E. S indicates the compartment for the spleen. It
is closed in front and below by the splenic process of peritoneum. M and N are the compartments on each side of the falciform ligament.


a point a little to the right of the middle line outwards to the right
(4) Above the root of the mesentery, and below the transverse colon and mesocolon, is the supra-mesenteric recess or compartment (see fig. 11, O).


abdominal wall (see fig. 11).
(5) The right and left suhdiaphragmatic recesses are placed between the liver and the diaphragm on each side of the falciform ligament (see fig. 11, M, N).1 _,
Thus a compartment was formed between the transverse colon and
great omentum below and the visceral surface of the liver above.
Studies of the Intestine and Peritoneum in the Human Foetus 507


Inflammatory effusions from the stomach, liver, or gall-bladder would‘
readily have collected in it; and it would have formed an important
barrier in restricting their spread into the general peritoneal cavity. It
formed, as it were, a ready-made abscess cavity (see fig. 11, D) shutting off
the right portion of the recess, between the liver and the transverse colon
and mesocolon, to which the name of the hepato—c0lic recess may be given.


(2) The pre-splenic fold of the splenic process of peritoneum is present
===B. Subdivisions of the Lesser Sac of Peritonenm===
normally in the adult. The sub-splenic part of this process is also sometimes seen as a distinct fold in the adult.‘ When fully developed it adheres
I have already shown that, through the continuity of the superior with the inferior area of gastric adhesion, the lesser sac of peritoneum may be subdivided into two compartments—(a) the hepatic or minor compartment (see fig. 11, A), and (b) the major compartment (see fig. 11, B).
to the diaphragm; and in several adults I have noted that, as the presplenic fold lies between the spleen and the diaphragm, it adhered to the
diaphragm, as well as to the diaphragmatic surface of the spleen. Thus
the spleen comes to lie in a definite compartment,closed in front and below
by the splenic process. This compartment may be termed the splenic compartment or recess (see fig. 11, S).


(3) The space beneath the transverse colon and mesocolon to the left of
In the papers I have now published on the intestine and peritoneum new names have been introduced into anatomy ; and I have named the parts only after a careful study of their relations (primitive and ultimate). At the same time, I have kept in mind any importance that these parts might have, or acquire, especially from a surgical or gynaecological point of view. I have avoided, as far as possible, altering any name given to a part by its original discoverer. But in some cases this was really necessary as the descriptions given were most inadequate. In some cases one had to add another name to an old one. Thus there are two areas of gastric adhesion, not simply one area which is “ bare” as regards its peritoneum. There are also two root-folds.
the duodeno-jejunal flexure, and below the root of the mesentery, may be
termed the sub-mesenteric recess. The genito-mesenteric fold, when present,
divides this into right and left sub-mesenteric recesses (see fig. 11, E, F).


The caecum2 and appendix lie in the right recess; the pelvic colon lies
The following is a list of some of the names I have introduced :—
in the left. .
 
In some cases, as in one which I record in another paper, it would
appear to be best to cut through the left (genito-mesenteric) wall (to which
the appendix and meso—appendix adhere) of the right sub-mesenteric recess
in order to reach the appendix. If this can be done, considerable tearing
and rough usage of the peritoneum by the surgeon would be avoided. The
 
1 Since describing it I have seen the sub-splenic fold, distinct and well marked, in two
adults. In both it adhered to the diaphragm and formed the sus ensory ligament of the
spleen. In one it co-existed with the phreno-colic-ligament of Tol t ; in the other, Toldt’s
ligament had not developed.
 
2 It is, of course, important to remember that, in the adult, the caocum may he found
lying in the central region of the abdomen at any point between the umbilicus (at which
it lies in my 37-mm. foetus) and pelvic cavity, into which it may also descend.
 
In the right lateral region I found the caccum of an adult wedged between the liver
and the diaphragm. Engel has noted a similar case. In this region it may also lie at any
level below the liver In my 12- to 22-cm. fwtuses it lies in front of the right kidney, or
immediately below it. In this latter situation the appendix is usually in a retro-colic
plane, and, as a rule, after ascending to the kidney is bent downwards and thus accommodates itself to the space available between the kidney and the parietal peritoneum
below this prominent organ.
 
If the lower part of the ascending colon be free, the caccum may be pushed upwards
by coils of small intestine, but yet could be pulled downwards by the surgeon (see my paper
in the Journal of Anatomy and Physiology, vol. xlvi. p. 239).
 
The ceccum has also been found lying in the left iliac fossa. “Remarquons—que le
 
czecum peut faire partie de toute les hernies ombilicale, crurale, inguinale, et meme du cote
gauche.”
508 Mr Douglas G. Reid
 
small intestine should first be pulled forwards. The genito—mesenteric fold
isthus exposed.
 
(4) Above the root of the mesentery, and below the transverse colon and
mesocolon, is the supra-mesenteric recess or compartment (see fig. 11, O).
 
(5) The right and left suhdiaphragmatic recesses are placed between the
liver and the diaphragm on each side of the falciform ligament (see fig. 11,
M, N).1 _,
 
B. Subdivisions of the Lesser Sac of Peritonenm.—I have already
shown that, through the continuity of the superior with the inferior area
of gastric adhesion, the lesser sac of peritoneum may be subdivided into
two compartments—(a) the hepatic or minor compartment (see fig. 11, A),
and (b) the major compartment (see fig. 11, B).
 
In the papers I have now published on the intestine and peritoneum new
names have been introduced into anatomy ; and I have named the parts only
after a careful study of their relations (primitive and ultimate). At the same
time, I have kept in mind any importance that these parts might have, or
acquire, especially from a surgical or gynaecological point of view. I have
avoided, as far as possible, altering any name given to a part by its original
discoverer. But in some cases this was really necessary as the descriptions
given were most inadequate. In some cases one had to add another name to
an old one. Thus there are two areas of gastric adhesion, not simply one area
which is “ bare” as regards its peritoneum. There are also two root-folds.


The following is a list of some of the names I have introduced :—
1. The Genito-mesenteric Fold.


]. The Genito-mesenteric Fold.
2. The Root-folds and Root-fossae.


J (a) The Left or Superior Root-fold and
:(a) The Left or Superior Root-fold and Root-fossae.
.  R _f  d Root-fossa.
:(b) The Right or Inferior Root-fold (Mesenterico-caecal Fold of Jonnesco) and Root-fossa.
2 Isootfi-:28; 5 an (b) The Right or Inferior Root-fold (Mes' l enterico-caecal Fold of J onnesco)
and Root-fossa.


3. The Caeco-appendicular Fold.
3. The Caeco-appendicular Fold.


(a) The M-shaped Form.
4. The Pelvic (Jonnesco) or Ilio-pelvic Colon.
(b) The Compressed Omega Form.
4. The Pelvic (J onnesco) or (c) The Compressed and Incompletely
Ilio-pelvic Colon. Inverted Omega Form.
(There is also (cl) an Omega (Treves)
Form.)
1 I11 operating for perforated astric ulcer “ the sub-diaphragmatic spaces are. especially
liable to be overlooked ” (Treves, anual of Operative Surgery). “ Special attention should


be directed to the space between the diaphragm and the liver on each side of the sus ensory
:(a) The M-shaped Form.
li ament, (and) the space between the stomach and the spleen ” (Alexis Thomson an Miles,
:(b) The Compressed Omega Form.
:(c) The Compressed and Incompletely  Inverted Omega Form. (There is also (cl) an Omega (Treves) Form.)


anual of Surgery).
Studies of the Intestine and Peritoneum in the Human Foetus 509


5. The Splenic Process of (a) The Pre-splenic Part or Fold.
5. The Splenic Process of Peritoneum.
Peritoneum. (b) The Sub—splenic Part or Fold.


(a) The Superior Area of Gastric Adhe
:(a) The Pre-splenic Part or Fold.
6. The Areas of Gastric sion (“bare area”)
:(b) The Sub—splenic Part or Fold.
Adhesion. (b) The Inferior Area of Gastric Adhesion.


7. The Supra-adhesion Foramen. (The Spigelian Uncus (described in
6. The Areas of Gastric Adhesion.
my “ Studies,” Part IV.) when present abuts against this foramen.)


(a) The Retro - pancreatico - duodenal
:(a) The Superior Area of Gastric Adhesion (“bare area”)
Fossa.
:(b) The Inferior Area of Gastric Adhesion.


(b) The Superior Retro-duodenal Fossa.
7. The Supra-adhesion Foramen. (The Spigelian Uncus (described in my “ Studies,” Part IV.) when present abuts against this foramen.)
(c) The Intermediate, Middle, or Lateral
Retro-duodenal Fossa.


(d) The Inferior Retro-duodenal F ossa
:(a) The Retro - pancreatico - duodenal Fossa.
(Retro-duodenal Fossa of J onnesco).
:(b) The Superior Retro-duodenal Fossa.
:(c) The Intermediate, Middle, or Lateral Retro-duodenal Fossa.
:(d) The Inferior Retro-duodenal F ossa (Retro-duodenal Fossa of J onnesco).


8. The Retro-duodenal
8. The Retro-duodenal Fossae.
Fossae.


9. The Retro-pancreatico-duodenal Recess.
9. The Retro-pancreatico-duodenal Recess.


* 1 In operating for perforated astric ulcer “ the sub-diaphragmatic spaces are. especially liable to be overlooked ” (Treves, anual of Operative Surgery). “ Special attention should be directed to the space between the diaphragm and the liver on each side of the sus ensory li ament, (and) the space between the stomach and the spleen ” (Alexis Thomson an Miles, Manual of Surgery).


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[[Category:Gastrointestinal Tract]][[Category:Intestine]][[Category:1910's]][[Category:Draft]]
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Reid DG. Studies of the intestine and peritoneum in the human foetus: Part VI. (1913) J Anat Physiol. 47(4): 486-509. PMID 17232976

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This 1913 paper is the sixth in this historical series describing human fetal intestine development. Note many of the terms introduced in this paper are historic terminology, no longer applied to describing the intestinal anatomy and some intestinal developmental concepts have been reviewed since this early series.

Other papers in this 6 part series by Douglas Reid:

  1. Reid DG. Studies of the Intestine and Peritoneum in the Human Foetus: Part I. (1911) J Anat Physiol. 45(2): 73-84. PMID 17232876
  2. Reid DG. Studies of the Intestine and Peritoneum in the Human Foetus: Part II. (1911) 45(4):406-15. PMID 17232897
  3. Reid DG. Studies of the Intestine and Peritoneum in the Human Foetus: Part III. (1912) 46(4):400-415. PMID17232936
  4. Reid DG. Studies of the Intestine and Peritoneum in the Human Foetus: Part IV. (1913) J Anat Physiol. 47(3): 255-267. PMID 17232956
  5. Reid DG. Studies of the Intestine and Peritoneum in the Human Foetus: Part V. (1913) J Anat Physiol. 47(3): 268-281. PMID 17232957
  6. Reid DG. Studies of the intestine and peritoneum in the human foetus: Part VI. (1913) J Anat Physiol. 47(4): 486-509. PMID 17232976


See also the historic paper Frazer JE. and Robbins RH. On the factors concerned in causing rotation of the intestine in man. (1915) J Anat. 50(1): 75-110. PMID 17233053
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Historic Embryology - Gastrointestinal Tract  
1878 Alimentary Canal | 1882 The Organs of the Inner Germ-Layer The Alimentary Tube with its Appended Organs | 1884 Great omentum and transverse mesocolon | 1902 Meckel's diverticulum | 1902 The Organs of Digestion | 1903 Submaxillary Gland | 1906 Liver | 1907 Development of the Digestive System | 1907 Atlas | 1907 23 Somite Embryo | 1908 Liver | 1908 Liver and Vascular | 1910 Mucous membrane Oesophagus to Small Intestine | 1910 Large intestine and Vermiform process | 1911-13 Intestine and Peritoneum - Part 1 | Part 2 | Part 3 | Part 5 | Part 6 | 1912 Digestive Tract | 1912 Stomach | 1914 Digestive Tract | 1914 Intestines | 1914 Rectum | 1915 Pharynx | 1915 Intestinal Rotation | 1917 Entodermal Canal | 1918 Anatomy | 1921 Alimentary Tube | 1932 Gall Bladder | 1939 Alimentary Canal Looping | 1940 Duodenum anomalies | 2008 Liver | 2016 GIT Notes | Historic Disclaimer
Human Embryo: 1908 13-14 Somite Embryo | 1921 Liver Suspensory Ligament | 1926 22 Somite Embryo | 1907 23 Somite Embryo | 1937 25 Somite Embryo | 1914 27 Somite Embryo | 1914 Week 7 Embryo
Animal Development: 1913 Chicken | 1951 Frog
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Pages where the terms "Historic" (textbooks, papers, people, recommendations) appear on this site, and sections within pages where this disclaimer appears, indicate that the content and scientific understanding are specific to the time of publication. This means that while some scientific descriptions are still accurate, the terminology and interpretation of the developmental mechanisms reflect the understanding at the time of original publication and those of the preceding periods, these terms, interpretations and recommendations may not reflect our current scientific understanding.     (More? Embryology History | Historic Embryology Papers)

Studies Of The Intestine And Peritoneum In The Human Foetus

By Douglas G. Reid, M.B., Ch.B. Edin., B.A. Trin. Coll. Camb.,

Demonstrator of Anatomy in the University of Cambridge.

Part VI. The Duodenum, with a note on the Subdivision of the Abdominal Cavity by Peritoneal Folds and Adhesions

Synopsis of the Present Study - The retro-duodenal fossae are first considered; then the retro-pancreatico-duodenal recess; the development of the duodenum ; the relations of the peritoneum of the intestinal loop to the duodenum; the special relations of the duodenum; and the genesis of certain folds of peritoneum in relation to this part of the bowel. Lastly, I consider points of surgical interest in connexion with the natural subdivision of the abdominal cavity into compartments or recesses.


Preliminary Remarks - Cleland (see the Journal of Anatomy and Physiology, vols. i. and iii.) was chief amongst those who in this country advocated the displacement theory. He speaks of the duodenum “pushing its way underneath the peritoneum of the parieties”; for “ other viscera growing faster are thought to pull it (the meso-duodenum) away and appropriate it” (Brockway in Gray's Anatomy, 1897). He regards the left half of the transverse colon as being formed from “the terminal intestine” (the part of the large intestine which extends from the colon at the splenic flexure (see fig. 6) to the proctodaeum (Jonnesco) ). He states that, “as far as is at present known, the adhesion of serous surfaces only occurs as the result of pathological changes.”


At first, indeed, it may appear diflicult to see how, as first asserted by His and Toldt, the still mesial splenic flexure of an embryo 25 mm. long (see fig. 6) can gain the position it occupies in a foetus 37 mm. long (see fig. 8).‘ In this country the wheels of the displacement theory were still further sunk in the ruck by the writings of Bruce Young, Lockwood, Treves, and others.


Byron Robinson (Journal of Anatomy and Physiology, 1899, vol. xxxiii.) discusses the two “theories” (Toldt’s and other) without prejudice; and gradually British authors have been coming to regard the adhesion “theory” as the one which more probably expresses the truth.


  • 1 According to Flower (Medical Times and Gazette, 1872, vol. i.), the whole of the transverse colon is erived from the terminal intestine.


Behind the head of the pancreas lies the fascia described by Treitz (see fig. 9).

In front of the head of the pancreas there is also a layer of fascia described by Toldt (“the pre-pancreatic fascia ” of Fredet, see figs. 5, 9).

No attempt has been made by those who advocate the displacement theory to account for these fascias.’ One can hardly doubt (see fig. 5) that they represent the meso-_duodenum. I have frequently demonstrated the fascia of Treitz. So compact a layer may it form in the adult as well as in the foetus, that it can readily be mistaken, at first, for normal endotheliumcovered peritoneum if the dissection to expose it has not been watched.

The prostato-peritoneal aponeurosis of Denonvilliersl also represents the connective element of peritoneum (cf. fig. 6 in Part IV. of my “Studies,” Journal of Anatomy and Physiology, vol. xlvii.).

But if any doubt could be expressed, I have, apart from all this, given numerous illustrations of the_ truth of the statement" (which therefore ceases to express a “theory ”) that two nolrmal endothelial surfaces of peritoneum can adhere to one another.

Mall? states that it has been customary to call his second and third loops of small intestine (his third loop corresponds to loop A in fig. 6, the part there named “duodenum” being his first loop) the duodenum. “. . . more mature consideration of models convinced me that loops 2 and 3 are finally transferred to the left side of the body to form the upper part of the jejunum.”

How, then, is the mesentery at its root attached to the fourth (ascending) portion of the adult duodenum ?

I have drawn attention to how certain folds of peritoneum may arise, and have pointed out the particular variations of the small and large intestine which result from displacement or from resistance to growth in certain directions.

Treves has attempted to explain the origin of the inferior duodenal fold. His explanation involves the duodenum being “drawn between the layers of its own meso-duodenum.”

One must try, however, to determine how physical forces really do operate in the production of certain of the peritoneal folds; for even if this particular fold be present in “nearly all mammals,” it would, of course, be a complete mistake “to think that ‘heredity’ will build up organic beings without mechanical means.”


  • 1 “ En arriere de la prostate, entre les vésicules séminales et le rectum, existe une couche membraneuse bien distmcte, que j’appelle 1-ostato-péritonéale-—par son bord postérieur, elle adhere a cette portion du péritoine qui escend entre la vessie et le rectum” (Denou villiers, quoted by Proust, La Prostatectomie, p. 160).
  • 2 The Johns Hopkins Hospital Bulletin, Nos. 90-91, September—October 1898.

The Retro-Duodenal Fossae

The retro-duodenal fossae which I shall now describe may be tabulated as follows : — (1) The retro—pancreatico-duodenal fossa. (2) The superior retro—duodenal fossa. (3) The intermediate, middle, or lateral retro-duodenal fossa. (4«) The inferior retro-duodenal fossa.‘


The Retro—panc'reatico—duodenal Fossa. — This fossa (see figs. 1, 2) was found by me in a full—time foetus. It is bounded in front by the first and second portions of the duodenum, and by the head of the pancreas; behind, by the parietal peritoneum in front of the inferior vena cava. On the right it is closed in by the duodeno-renal ligament and the genito—mesenteric fold. It extends towards the left as far as the aorta, and downwards as far as the upper border of the third part of the duodenum. It opens above into the vestibule of the lesser sac of peritoneum, and into the greater sac at the foramen of Winslow. It results from the conversion into a fossa of the retro-pancreatico-duodenal recess presently to be described.”

The Superior Retro-duodenal Fossa. — This fossa (see fig. 2) was found by me in an adult body dissected at Cambridge several years ago. It lay behind practically the Whole of the fourth portion of the duodenum. Its orifice, situated opposite the duodeno-jejunal flexure, was directed upwards and bounded on the sides by the free margins of two folds of peritoneum which passed from the parietal peritoneum and the mesocolon at its root. Its orifice thus rather resembles that of the duodeno-jej unal fossa described by Jonnesco in 1889, and situated “au niveau de 1’angle duodéno-jéjunal, entre son dos et la racine du mésocolon transverse.”

The Intermediate Retro-duodenal Fossa.—This fossa (see fig. 2) was found, well marked, by me in five out of twenty of the 12- to 22—cm. foetuses specially examined. It lies behind the fourth portion of the duodenum.

Its orifice, directed towards the left, is bounded above by the inferior mesenteric vein and the superior duodenal fold; below, by the inferior duodenal fold. The depth of the fossa may equal, but never exceeds, the diameter of the part of the duodenum to which it is related ('i.e. the fossa never passes behind the head of the pancreas). I have found it, equal in depth to the diameter of the fourth portion of the duodenum, in full—time foetuses; and have noted similar, but usually rather shallow, intermediate retro—duodenal fossee in adult bodies.


  • 1 Discovered by J onnesco in 1893, and described by him as “ the retro-duodenal fossa.”
  • 2 I have only recently begun to look for this fossa in the adult. It certainly appeared to have been present to a slight de ree in a body dissected at Cambridge, Lent Term, 1913. But, unfortunately, the dissectors Tied unconsciously enlarged it in a. downward direction before I saw the exact state of affairs.


Fig. 1. The arrangement of the peritoneum in relation to the duodenum of a full-time foetus is accurately represented. The great omentum is not figured. The interrupted line indicates the extent of the retroduodenal fossa present between the head of the pancreas and the inferior vena cava. The line of the aorta. marks its extent towards the left. The arrow indicates the orifice of the fossa. The peritoneum of the intestinal loop has not fused down over the anterior surfaces of the filst, second, and third portions of the duodenum. The sheet of peritoneum (A, A) is continued from it, however, over the anterior surface of the seconul part of the duodenum, into the duoxleno-renal ligament and genito-mesenteric fold. These sheets are all continuous. It, is noteworthy that the genito-mesenteric fold is attached to the lowest part of the duodenum.

The fold which contains the hepatic artery, and which forms part of the septum bursarum omentalium, represents (Swaen) meso-duodenum from which the duodenum has retracted. The upper free edge represents the upper border of the meso-duodenum. “ Le transport de l’estomac, sa saillie si prononcéc dans la moitié gauche dc la cavité abdominale, a entrainé dans cette direction la. premiere portion du duodenum qui l11i fait suit, 1’a inclinée vers la gauche, l’a fait sortir du méso duodenum” (Swaen, p 164, Bibliographic Anatormque, tome vii., 1899). The adhesion of the posterior surface of the duodenum (as well as that of the stomach) to the transverse mesocolou is therefore, of course, secondary.

In this specimen the appendix and meso-appendix do not adhere to the genito-mesenteric fold. The mesenteric border of the meso-appendix passes (along the line of a branch of the artery to the appendix) towards the mesenteric border (the anterior part of which lies along the line of the ileac branch of the ileo-colic artery) of the genito-mesenteric fold. but fails to reach it by a distance of 4 mm. (of. fig. 11).


Fig. 2. The four retro-duodenal fossae are shown. The duodenum is represented cut at its junction with the jejunum. The arrows indicate the orifices of the fossm (represented by interrupted lines and stippling).

(1) The lower limit of the retro-pancreaticoeduodenal fossa (seen by me in a full-time foetus) whose entrance is at A.

(2) The lower limit, approximately, of the retro-duodenal fossa (seen by me in the adult) whose orifice is at D; and the right limit of the retro-duonlenal fossa (seen by J onnesco in the adult) whose orifice is at B.

(3) The lower limit of the retro-duodenal fossa (seen by me in the adult) whose orifice is at E; and the lower limit of the retro-duodenal fossa (seen by me in the foetus, and similar to the fossa I have met with in the adult) whose orifice is at D.


Direct adhesions of the duodenum to the parietal peritoneum may take the place of the duodenal folds and bound the orifice of the fossa.

Thus, in an adult (dissected at Cambridge, Lent Term, 1913), the whole of the posterior surface of the fourth part of the duodenum was free. A distinct retro—duodenal fossa in this case, however, only existed below (see fig. 3). It extended towards the right nearly to the root of the ileo-colic artery, and was bounded on the left by a direct adhesion of the duodenum to the parietal peritoneum.


Again, the whole of the posterior surface of the fourth portion of the duodenum may be found free from adhesions without the formation of any fossa. Thus, in an adult, the fourth part of the duodenum, which was soldered down simply along its right border, could, to a certain extent, be made to swing backwards and forwards as on a hinge.



Fig. 3. The arrow indicates the orifice of the fossa.


When the posterior surface of the duodenum is free, jejunum may get in behind it and place itself in contact with the head of the pancreas at the left part of its circumference. This is seen in a 17-cm. foetus. Here the jejunum descends from the duodeno-jejunal flexure and, at a peritoneal fold resembling the inferior duodenal, makes a bend and passes upwards behind the fourth part of the duodenum. Here it lies in contact with the peritoneum covering the superior mesenteric artery and the left part of the border of the head of the pancreas. It comes into contact with the inferior surface of the body of the pancreas, and forms a flexure in the position normally occupied by the duodeno—_jejunal. It was firmly wedged in between the duodenum and the pancreas, but did not adhere to either. This is the nearest approach towards the development of a retroduodenal hernia that I have seen. A hernial sac might readily have been formed by the secondary formation of peritoneal adhesions, pathological or other.


Fig 4. Fetus 17 cm. long. The jejunum immediately succeeding the duodenum passes downwards and then bends upwards behind the fourth portion of the duodenum. It comes into contact with the inferior surface of the body of the pancreas, and here forms 9. flexure which corresponds in position to the normal duodeno-jejunal flexure. The short descending part of the jejunum adheres along its right border to the duodenum, and to the parietal peritoneum down to the fold of peritoneum. Except for this, it is free, as is the rest of the jejunum.


I have noted apparent absence of the fourth part of the duodenum in an adult.‘

  • 1 I only saw this case, however, after the peritoneum had been subjected to some handlin ; and, as the parts were unusually soft, it is possible that if the fourth portion of the duo enuui had been unusually free it might have been dragged downwards. As in the other case referred to, the disscctors were unconscious of having done any mischief.

“ The Retro-duodenal Fossa” of Jonnesco.‘—In View of the retroduodenal fossae which I have described, I propose to call this fossa the inferior retro-duodenal fossa, a name which I understand has already been suggested for it. Any fossa in relation to the duodenum must, of course, be of interest

from a surgical point of view. “J’ajouterai seulement qu’elles out une grand importance practique, car elles sont le siege le plus habituel des hernies internes rétro-peritoneal dont j’ai pu réunir un nombre respectable


Fig. 5. Longitudinal section (u. little to the right of the vertebral column) of a foetus 17 cm. long.

Note the recess, containing the caudate lobe (process), behind the pancreas, and the relations of the right suprarenal body.

The Retro-Pancreatico-Duodenal Recess

When well developed, this recess (see fig. 5) lies behind the first and second portions of the duodenum and the head of the pancreas in relation to these parts. It may descend almost to the third part of the duodenum. I first observed it, well marked, in a 17-cm. foetus (see fig. 5).

1 This fossa ascends behinrl the fourth portion of the duodenum to the iluodeno-jejunal flexure. It is related to the third part of the duodenum to the (approximate) extent shown in fig. 2, and lies in front of the aorta. Its orifice looks downwar s.

2 It is known that'bowel may protrude into the foran1en of Winslow. It is therefore possible that a piece of intestine could get into a persistent retro- ancrea.tico~duodenal recess or fossa. Inflammation might also extend to the up er part 0 the head of the pancreas should intlammator effusions, from the stomach or uodenum especially, collect in such a recess. One shoul also remember that “au niveau de la portion supérieure [of the duodenum] la circonférence [of the head of the pancreas] présente un prolongement tantét it peine indiqué, tantot assez développé pour (lepasser la face postérieure du duodenum; c’est le prolongement supérieur ou rét1'odu0dé-nal” (Charpy in Poirier’s Anatomy, 1905, vol. iv. p. 822).


As in the 20-cm. foetus, a figure of which as seen in mesial section is given in Part IV. of my “Studies,” the pylorus, in this foetus, is placed opposite the disc between the eleventh and twelfth dorsal vertebrae; and the third portion of the duodenum, in the middle line, lies opposite the disc between the first and second lumbar vertebrae. The recess descends to a distance of 1 mm. from the third part of the duodenum.

Lying in this recess, between the duodenum and head of the pancreas in front and the inferior vena cava and the right suprarenal body behind, is a process of the caudate (Spigelian) lobe.

The anterior wall of the recess is of course continuous above with the postero—external surface of the fold which contains the hepatic artery. This fold represents a part of the meso—duodenum (see footnote, fig. 1).

The retro-pancreatico—duodenal recess is also present, well marked, in an 11-cm. foetus. Here it descends behind the first part of the duodenum, and behind the upper half of the head of the pancreas and an exactly corresponding part of the second portion of the duodenum. Its posterior wall is formed by a small part of the right kidney in addition to the right suprarenal body and the inferior vena cava.

The recess is also seen in a 20-cm. foetus, but is related to the head of the pancreas only to a slight extent. I have since studied it in other foetuses.

In many there is a recess lying simply behind the first portion of the duodenum without coming into direct relation with the head of the pancreas. But,I am inclined to think that the caudate lobe (prdcess) of the liver, as it lies in this recess, .comes into contact with the head of the pancreas more frequently than I at first thought. Unless a section be made, in a downward direction, through the first part of the duodenum and the head of the pancreas, the true relations of the recess may readily be overlooked.

In a full-time foetus there is a retro-pancreatico-duodenal recess which descends behind the first portion of the duodenum and the upper part of the head of the pancreas. It also descends, in front of the right suprarenal body, behind the second portion of the duodenum in its upper half. The caudate lobe of the liver, although coming into contact with the upper part of the head of the pancreas, does not descend to the bottom of the recess (of. fig. 5). The anterior and posterior walls of the lower part of the recess thus come into contact with one another.

The retro-pancreatico-duodenal recess,‘ which should be looked for in the adult, is present in a 37-mm. foetus; and in it was lodged a portion of the liver. This I removed, exposing the smooth parietal peritoneum which forms the posterior wall of the recess.

  • 1 It is best to retain this name, even if the recess do not come into direct relation with the pancreas.


In a 25-mm. embryo the duodenum forms a small loop which lies in a plane markedly transverse (see fig. 6). The liver lies in contact 'with the whole of the upper surface of this loop.


As the liver becomes relatively reduced in size the duodenum is pushed into a more frontal plane, and a definite recess is formed. This tends to become smaller and smaller, the meso—duodenum fusing with the parietal peritoneum from below upwards, until ultimately the peritoneum covering the posterior surfaces of the first and second portions of the duodenum and head of the pancreas may be completely soldered down. Should the second part of the duodenum alone become adherent to the parietal peritoneum, or to the left surface of the genito-mesenteric fold (see fig. 1), the retro—pancreatico—duodenal fossa is of course formed. Although the recess be present, the mesentery of the intestinal loop has already adhered to the anterior lamina of the meso—duodenum within the duodenal loop of the 37-mm. foetus (see fig. 8, “secondary root—area ”).

In the 25-mm. embryo intestinal torsion is still incomplete (see fig. 6).

In association with the recess in the larger foetuses, the colon, passing from the front of the right kidney, has to course markedly forwards upon the second portion of the duodenum to reach the first portion of the duodenum and the region of the pylorus (see fig. 5). All three structuresduodenum, pancreas, and transverse colon—are propped forwards, as it were, by the caudate lobe of the liver. The posterior surface of the head of the pancreas looks decidedly upwards as well as backwards (see fig. 5).

Chiefly Concerning the Development of the Duodenum

Mall has already drawn attention to the large size of the embryonic duodenufn.

In my 25-mm. embryo it is seen that the ornphalo-mesenteric vessels pass behind a portion of the alimentary canal (see fig. 6, “duodenum ") ; and one can have little doubt that this at least is part of the duodenum. From the point where these vessels come into this relation with the bowel, the intestine passes markedly backwards towards the posterior (dorsal) abdominal wall, and, bending inwards to some extent, comes into contact with the mesial mesentery at the neck of the intestinal loop. This inward bend is well shown in Mall’s fig. 10 of a 28-mm. foetus.

The intestine now passes forwards and becomes continuous with Mall’s third loop (loop A in fig. 6).

The part which thus passes forwards into A forms with the part that passes backwards a loop, the convex surface of which looks backwards and also inwards (see “fig. 6); and at the summit of the curve the small intestine actually adheres, just abovethe splenic flexure, to the right surface of the mesial mesentery at the neck of the intestinal loop.‘


FIG. 6.-—-Embryo 25 mm. long dissected to show the intestinal loop. The head is represented more erect than is normal ; and the trunk has been somewhat straightened. Loop A overlaps the om halo-mesenteric vessels; and the parts of the small intestine in front of the knifeblade :3 so meet in front of these vessels. The omphalo-mesenteric vessels, which lie in a ridge of peritoneum, cross in front of loop D ; and this loop has a limb on each side of these vessels. The appendix is already distinguished by its small diameter. The splenic flexure lies immediately below the stomach in the middle line. The root of the mesentery of the terminal intestine is still mesial. There is no Meckel’s diverticulum. The anterior surface of the large stomach looks upwards as well as forwards Studies of the Intestine and Peritoneum in the Human Foetus 497


It is jammed against this mesentery by the large liver. The part of the small intestine which extends backwards and inwards and is crossed by the vitelline vein is without doubt the duodenum. It is in the median line at its posterior extremity; and this is relatively fixed in position. Therefore, as the duodenum elongates, a more pronounced loop, concave towards the left, is formed.

Already its first, second, and third parts are distinguishable.

I have already noted that it lies, with part of the liver directly above it, in a plane which is markedly transverse (horizontal). The manner in which the retro-pancreatico-duodenal recess is definitely formed has also been indicated. .

But the fourth (ascending) portion of the duodenum has yet to be formed.

The small intestine now begins to work its way under the large, moving about an axis which passes from the median posterior extremity of the duodenum to the caecum, still in the umbilical orifice of my 37-mm. foetus.

This movement has progressed to a considerable extent in this foetus

‘ (see fig. 7).

The splenic flexure has now passed as far to the left as it can (see fig. 8). The left part of the transverse colon is now formed, and the terminal intestine passes downwards, and then downwards and inwards, skirting the right margin of the left testis (see fig. 7). The root of its mesentery is still mesial, however. ‘

The small intestine appears to have pressed the mesentery of the colic portion of the intestinal loop upwards and backwards against the mesoduodenum, to the whole of which, within the concavity of the duodenal loop, it now firmly adheres, although the serous surfaces of the duodenum are still free. Thus is formed the secondary root-area (see fig. 8).


In the full-time foetus (see fig. 1) the fusions of the peritoneum in relation to the meso-duodenum have been arrested at a stage not much more advanced than this. A genito-mesenteric fold has developed which takes the place of the root of the mesentery and also anchors the duodenum.

The colon has gone on growing, and the caecum lies in the right iliac fossa. The left part of the transverse colon is formed, and the root of its mesentery is practically in the position it occupies in the adult.


  • 1 Only the examination of more material can determine if this occur normally. Here, again, there can be absolutely no doubt that two normal endothelial surfaces of peritoneum had adhered to one another.


The great omentum, adhering to the colon, helps to support this to the right of the meso—duodenum (“secondary root-area ”).

In the 37-mm. foetus the upper part of the jejunum, having now worked its way to the left, is already directed upwards to form a short fourth portion of the duodenum (see fig. 7). It is fused along its right border to the peritoneum of the intestinal loop Where this adheres to the mesoduodenum along the inner part of the circumference of the head of the pancreas. Its mesenteric border now becomes the upper part of the root of the mesentery.


FIG. 7.—Foetus 37 mm. long, 6. The interrupted lines in A indicate the position of the lower border of the liver and of the umbilical orifice. The upper border of the orifice lies 0 posite the lower border of the liver. In B the interrupted line indicates the course of the (111 enum. The parts of the intestine and mesentery which correspond are indicated by figures. The stomach and first part of the colon (passing backwards from the umbilicus) lie in a more horizontal plane than the figures appear to indicate. Normally, the testes and the descending colon are in contact with, and completely concealed in front by, small intestine. But the posterior abdominal wall has been straightened by traction exerted upon it through the hook, and they are thus rendered visible.


It is stated in Poirier’s Anatomy that the root of the mesentery upon the fourth portion of the duodenum is something new, the result of a process of adhesion of the peritoneum of the intestinal loop to the meso-duodenum between the superior mesenteric artery and the duodeno—jejunal flexure.

But all the evidence I have is in favour of this part of the root of the mesentery being simply the intestinal border of the mesentery of the small intestine. It has always been present.



Fm. 8.—Dia.gram to illustrate the arrangement of the peritoneum in a. 37-mm. foetus. The ciecum is supposed to have been pulled from the umbilical orifice (in which it lay) towards the right. The posterior (direct) layer of the great omentum has been cut at its junction with the anterior (reflected) layer. The mesentery of the intestinal loop has fused to the mesoduodenum where this covers the head of the pancreas, and the “secondary root-area. "is thus formed. The anterior and posterior surfaces of the duodenum are still free; and the retropancreatico-duodenal space contains part of the liver. The roots of the meso-gastrium and meso-duodenum, and the root of the mesentery of the intestinal loop (secondary root-area) and that of the terminal intestine, are still practically in the middle line


This view of the origin of the fourth portion of the duodenum is further supported by the fact that the fossae which may lie behind this part never extend behind the head of the pancreas.

The root of the mesentery is completed by the fusion, to the parietal peritoneum and to the duodenum, of the colic portion of the mesentery of 500 Mr Douglas G. Reid

the intestinal loop, downwards to the line of the ileo—colic vessels (see figs. 1, 4, 5, 9, 10).

A blood-vessel lying in a sheet of peritoneum forms a relatively rigid bar about which, as an axis, one part of the sheet may rotate towards another part.

I have already shown that such a plication may determine the position of the arteries along the root of the pelvic mesocolon (see my “Studies,” Part II.).

In the same way, such a plication will determine the position of the ileo—colic vessels along the root of the mesentery, since the more passive colic part of the mesentery of the intestinal loop can, as a rule, solder to the posterior peritoneum downwards to the line of these vessels, about which the small intestinal part of the mesentery of the intestinal loop has rotated forwards, but no farther. The development of the genito-mesenteric fold, however, may cause a displacement of the root of the mesentery from this line (see my “Studies,” Part I.).

The intermediate retro-duodenal fossa would appear to result from the soldering down of the bowel which forms the fourth portion of the duodenum occurring first along the left aspect of the head "of the pancreas and the superior mesenteric artery, and in the region Where the inferior mesenteric vein may come into relation with the superior duodenal fold. If the adhesion extend towards the left, the fossa will become shallower, and may finally be obliterated.

The part of the bowel which is most fixed through its relations to other relatively immovable parts is the part which first tends to solder down.‘

The Relations or the Peritoneum or the Intestinal Loop to the Duodenum

The colon usually lies parallel to the first portion of the duodenum. It lies along the lower border, or upon the anterior surface of this part (see figs. 5, 9).

In five out of twenty foetuses (20 per cent. of cases) it forms a small loop (the right colic loop of J onnesco) as it lies opposite the duodenum.

There are two chief arrangements (see fig. 9).

(1) The peritoneum of the intestinal loop becomes adherent to the whole of the permanently anterior lamina of the meso-duodenum up to the lower border of the first part of the duodenum. At this level it bends downWards upon itself, so that the previously posterior surface of the colon becomes anterior, and a short transverse mesocolon persists which may subsequently disappear as the result of fusion (see fig. 9, A). This is the condition which is already present in my 37-mm. foetus (see fig. 8). The meso—gastrium and the transverse mesocolon are still quite free from one another, but almost meet at the level of the lower border of the first part of the duodenum. The lower part of the root of the meso-gastrium and the upper limit of the secondary root-area lie close together (closer than could well be indicated in the figure).


  • 1 Jamming of viscera between relatively immovable parts may help to determine adhesion. Thus in four out of thirteen specimens the left extremity of the transverse colon is jammed between the ancreas and the spleen, and adheres, as in the adult, to the inferior surface of the body 0 the pancreas. In the other nine cases, althou h the colon is in contact with the body of the pancreas, there is no such jamming, an a fissure, the walls of which are lined by the meso-gastrium, intervenes between the colon and the pancreas.


FIG. 9.—Diagram to show the arrangement of the peritoneum opposite the duodenum. The angle marked + may disappear through fusion. In the left root-fold are lodged the ileo-colic artery and vein, nerve filaments, and a number of lymphatic nodes. This fold is described in Part II. of my “ Studies.”


(2) There is the same disposition without the persistence of a mesocolon (see fig. 9, B).

It has been noted in Part III. of my “Studies” that, after an arrangement has been acquired as described under (1), a secondary movement may occur of the transverse colon towards the left and headwards.

The colon and peritoneum of the intestinal loop always completely cover the meso-duodenum below and to the right of the pylorus.

In the 25—mm. embryo the meso-gastrium is free exactly to the extent indicated in fig. 8 for the 37-mm. foetus, but has not begun to project downwards beyond the stomach as in that foetus. Later it will fuse with the transverse mesocolon and colon, and still later the right omental process appears. When this develops, it extends, therefore, over the peritoneum of the intestinal loop, and not overvthe meso-duodenum such as is figured and described in the classics (see also fig. 10).



Fig. 10. 10.-—Foetus 127 cm. long. The peritoneum between the duodenum and the transverse colon belongs to the mesentery of the intestinal loop, and is not meso-duodenum. Therefore in this foetus had the right omental process developed later, it would have extended over peritoneum of the intestinal loop, not over meso-duodenum such as is figured and described in the classics (e.g. Poirier’s Anatomy). In all the other fcetuses the mesu-duodenum to the right of and below the pylorus is completely covered by the transverse colon and the mesentery of the intestinal loop (see fig. 9). The figures and descriptions given in the books dealing with the development of the peritoneum are inaccurate in this respect. The terminal intestine forms a loop which lies in the right iliac fossa.

The Special Relations of the Duodenum

(1) The caudate lobe (process) of the liver may lie directly behind the first and second portions of the duodenum, as has already been described. (2) The right suprarenal body may descend behind the duodenum to a marked extent (see fig. 5) ; and even when the caudate lobe lay in front of it to ‘the extent shown in fig. 5, it came into direct relation, below the liver, with the lower end of the second portion of the duodenum. When there is no marked recess it also comes into direct relation with the duodenum at the angle between its first and second parts. Indeed, it often descends behind the second portion to_the upper part of the junction of this with the third portion.


In the full-time foetus mentioned it lay behind the upper half of the second part of the duodenum. It may also come into _contact with the head of the pancreas (of. fig. 5) to the right side of the inferior vena cava. The left suprarenal body is an immediate relation of the duodenum at the duodeno-jejunal flexure.


(3) The genito-mesenteric fold gains an attachment to the duodenum (see fig. 1). The suspensory muscle of Treitz} “as Professor Cleland is in the habit of pointing out in his lectures, seems to have more importance than is usually attributed to it. . . . The duodenum may curve downwards even as far as the right iliac fossa,2 and yet its junction with the jejunum is always on the left side of the superior mesenteric artery, beneath the transverse mesocolon, owing to the suspension of this part of the small intestine by the musculus suspensorius duodeni.” This muscle undoubtedly tends to become hypertrophied when the duodenum is unusually free (see my paper “Imperfect Torsion of the Intestinal Loop,” Journal of Anatomy and Physiology, vol. xlii.).


But I have pointed out another probable cause of downward displacement of the duodenum. This is the traction which may apparently be exerted upon the duodenum at the junction of its second and third parts by the genito-mesenteric fold.


In an adult the duodenum, at this junction, descended to the level of the disc between the last lumbar and first sacral vertebrae (see fig. 3). This was most probably due to the unusually large cirrhotic liver.


Nevertheless, the genito-mesenteric fold should be kept in mind as another probable cause of some degree of downward displacement of the duodenum (see also footnote, fig. 1).


(4) The left root-fold lies in the foetus in front of the fourth portion of the duodenum, along the line of the root of the mesentery passing outwards towards the caecum (see figs. 4-, 5, 9, 10).

  • 1 A good figure of this muscle is given in Spalteholz’s Atlas (fig. 633). 2 It is interesting to note all the abnormal contents of this fossa—duodenum, trans verse colon, pelvic colon, liver, lower extremity of right kidney, testis of adult, etc. See also fig. 10. 504 Mr Douglas G. Reid


(5) The pelvic colon may ascend to the duodenum, and may also be distinctly overlapped by the left root—fold.1

The Genesis of Certain Folds of Peritoneum in Relation to the Duodenum

I have already shown (“ Studies,” Part III.) that if the “bloodless” fold of Treves adhere to the abdominal wall, it may become enormous through stretching during the descent of the caecum. I have also shown that folds may be present at the periphery of “the superior area of gastric adhesion” (“bare area”). A distinct fold may also be seen sometimes at the lower limit of the adhesions which bind the ascending colon to the parietal peritoneum.


In fig. 4 a fold is illustrated which lies at a bend of the bowel, and at the lower limit of the adhesions fixing down a part of the jejunum. It is very similar in appearance to the inferior duodenal fold which is present, as is also the superior, in a number of my 12 to 22-cm. foetuses.

Folds (see figs. 2, 3) may also be seen at the duodeno—_jejunal flexure connecting the bowel at this point with the transverse mesocolon.

At these points the connective elements of two originally distinct peritoneal sheets have, of course, become continuous with one another.

Just as in the case of the “ bloodless” fold, traction upon these connective elements, where they are continuous, will naturally tend to elongate them into a fold, provided the area of adhesion be not too diffuse. This will tend to occur most where stress is greatest, eg. at the duodeno-jejunal flexure.

At this flexure there is not only the traction exerted directly upon the adhering connective elements by the jejunum itself, but the stomach presses downwards upon the bowel, and the upper horizontal coils of small intestine press upon it from left to right. Stress also concentrates itself upon the duodenum at the angle between its third and fourth portions. Here there is the pressure exerted upon it from left to right by the upper horizontal coils, and from below by the vertical coils of small intestine.

Through traction upon the connective element of the outer coat» of the bowel some muscle fibres of the gut may also be drawn, as it were, into a peritoneal fold (see my paper on “The Caeco—appendicular Fold,” Journal of Anatomy and Physiology, vol. xlvi.).


  • 1 Should adhesions develop between the upper part of an omega loop of pelvic colon and the third part of the duodenum and adjoining mesentery and parietal peritoneum, the pelvic colon may remain permanently fixed in the abdominal cavity. I have recently seen this condition, due to strong adhesions, in two adult bodies otherwise normal as regards peritoneal adhesions. Apart from the question of this impairing the functional activity of the bowel, it is possible that in such cases dificulties might arise in an attempt to pull downwards the right limb of the omega loop in the operation of excision of the rectum by the sacral route where the growth is found to extend far upwards.


Traction or pressure exerted upon peritoneum on each side of a bloodvessel may also, in some "cases, produce a vascular fold. I have described such a fold in connection with the genito—mesenteric fold (“ Studies,” Part I., Journal of Anatomy and Physiology, vol. xlv.).


This idea is further illustrated in an 18—c1n. foetus. Here the upper part of the inferior mesenteric vein, taking its usual arched course, lay, above a point indicated by + in fig. 2, along the free margin of a fold of peritoneum which formed the anterior wall of a fossa 2'5 mm. deep. The left border of the fourth portion of the duodenum, up to the duodenojejunal flexure, was lodged in this fossa, but did not adhere to the fold. Had the duodenum adhered to the upper half of the fold, quite a typical superior duodenal fold, containing’ the inferior mesenteric Vein, and fossa would have been formed. V


Thus, if, as in this case, the fourth part of the duodenum, being practically fixed below, whilst at the duodeno—_jejunal flexure it is in contact with the pancreas and adheres to some extent to the transverse mesocolon, remain free behind, it may, during growth, find space for itself by burrowing its way, as it were, under the vein.

These views, of course, do not imply that endothelium is dragged off some other part in order to coat the fold which is produced. In some cases such a fold may disappear later through fusion with adjacent peritoneum.

The cystocolic ligament is present in 30 per cent. of foetuses. I have included in this some cases in which the colon adheres directly to the body of the gall-bladder. In the two cases I have mentioned_in which there is a well-marked retro-pancreatico-duodenal recess the colon and duodenum, adhering together, are propped forwards, as it Were, by the caudate-lobe of the liver lying in this recess (see fig. 5); and both adhere directly to the body of the gall-bladder at the angle between the first and second parts of the duodenum. The endothelial surfaces, thus brought together, are directly continuous with those of the lesser omentum.

Thus we have the birth of What obviously could become later a definite cystocolic fold continuous with the lesser omentum, and passing over the duodenum, to the colon. I have indicated in Part III. of my “Studies” that a direct adhesion of the colon to the lesser omentum may sometimes also give rise to this ligament.

Peritoneal bands consequent upon inflammation may also, of course, arise through direct adhesions and subsequent elongation the result of traction.

The Subdivision of the Abdominal Cavity by Peritoneal Folds and Adhesions

A. Subdivisions of the Greater Sac of Peritoneum

(1) In two adult bodies dissected at Cambridge, Lent Term, 1913, I found the great omentuin adhering to the anterior abdominal wall along an uninterrupted line from a point a little to the right of the middle line outwards to the right abdominal wall (see fig. 11). Thus a compartment was formed between the transverse colon and great omentum below and the visceral surface of the liver above.


Fig. 11. This figure, constructed from three specimens (two adults and a foetus) examined by me in the Cambridge dissecting-room, Lent Term, 1913, illustrates the subdivision, more or less complete, of the abdominal cavity by peritoneal folds and adhesions. A and B indicate the two compartments of the lesser sac (represented by an interrupted line) resulting from the continuity of the superior and inferior areas of gastric adhesion. D and 0 indicate the compartments formed through an adhesion, in both adults, of the great omentum to the anterior and right abdominal walls. E and F are the compartments, below the mesentery, to the right and left of the genito-mesenteric fold. The pelvic colon (the M-shaped form was resent. well marked, in one of the adults) occupies compartment F; the caecum and appen ix, and part of the ileum, occupy compartment E. S indicates the compartment for the spleen. It is closed in front and below by the splenic process of peritoneum. M and N are the compartments on each side of the falciform ligament.


Inflammatory effusions from the stomach, liver, or gall-bladder would‘ readily have collected in it; and it would have formed an important barrier in restricting their spread into the general peritoneal cavity. It formed, as it were, a ready-made abscess cavity (see fig. 11, D) shutting off the right portion of the recess, between the liver and the transverse colon and mesocolon, to which the name of the hepato—c0lic recess may be given.


(2) The pre-splenic fold of the splenic process of peritoneum is present normally in the adult. The sub-splenic part of this process is also sometimes seen as a distinct fold in the adult.‘ When fully developed it adheres to the diaphragm; and in several adults I have noted that, as the presplenic fold lies between the spleen and the diaphragm, it adhered to the diaphragm, as well as to the diaphragmatic surface of the spleen. Thus the spleen comes to lie in a definite compartment,closed in front and below by the splenic process. This compartment may be termed the splenic compartment or recess (see fig. 11, S).


(3) The space beneath the transverse colon and mesocolon to the left of the duodeno-jejunal flexure, and below the root of the mesentery, may be termed the sub-mesenteric recess. The genito-mesenteric fold, when present, divides this into right and left sub-mesenteric recesses (see fig. 11, E, F).


The caecum2 and appendix lie in the right recess; the pelvic colon lies in the left.

In some cases, as in one which I record in another paper, it would appear to be best to cut through the left (genito-mesenteric) wall (to which the appendix and meso—appendix adhere) of the right sub-mesenteric recess in order to reach the appendix. If this can be done, considerable tearing and rough usage of the peritoneum by the surgeon would be avoided. The small intestine should first be pulled forwards. The genito—mesenteric fold isthus exposed.

  • 1 Since describing it I have seen the sub-splenic fold, distinct and well marked, in two adults. In both it adhered to the diaphragm and formed the suspensory ligament of the spleen. In one it co-existed with the phreno-colic-ligament of Tol t ; in the other, Toldt’s ligament had not developed.
  • 2 It is, of course, important to remember that, in the adult, the caocum may he found lying in the central region of the abdomen at any point between the umbilicus (at which it lies in my 37-mm. foetus) and pelvic cavity, into which it may also descend.


In the right lateral region I found the caccum of an adult wedged between the liver and the diaphragm. Engel has noted a similar case. In this region it may also lie at any level below the liver In my 12- to 22-cm. fwtuses it lies in front of the right kidney, or immediately below it. In this latter situation the appendix is usually in a retro-colic plane, and, as a rule, after ascending to the kidney is bent downwards and thus accommodates itself to the space available between the kidney and the parietal peritoneum below this prominent organ.


If the lower part of the ascending colon be free, the caccum may be pushed upwards by coils of small intestine, but yet could be pulled downwards by the surgeon (see my paper in the Journal of Anatomy and Physiology, vol. xlvi. p. 239).


The ceccum has also been found lying in the left iliac fossa. “Remarquons—que le czecum peut faire partie de toute les hernies ombilicale, crurale, inguinale, et meme du cote gauche.”


(4) Above the root of the mesentery, and below the transverse colon and mesocolon, is the supra-mesenteric recess or compartment (see fig. 11, O).

(5) The right and left suhdiaphragmatic recesses are placed between the liver and the diaphragm on each side of the falciform ligament (see fig. 11, M, N).1 _,


B. Subdivisions of the Lesser Sac of Peritonenm

I have already shown that, through the continuity of the superior with the inferior area of gastric adhesion, the lesser sac of peritoneum may be subdivided into two compartments—(a) the hepatic or minor compartment (see fig. 11, A), and (b) the major compartment (see fig. 11, B).

In the papers I have now published on the intestine and peritoneum new names have been introduced into anatomy ; and I have named the parts only after a careful study of their relations (primitive and ultimate). At the same time, I have kept in mind any importance that these parts might have, or acquire, especially from a surgical or gynaecological point of view. I have avoided, as far as possible, altering any name given to a part by its original discoverer. But in some cases this was really necessary as the descriptions given were most inadequate. In some cases one had to add another name to an old one. Thus there are two areas of gastric adhesion, not simply one area which is “ bare” as regards its peritoneum. There are also two root-folds.

The following is a list of some of the names I have introduced :—

1. The Genito-mesenteric Fold.

2. The Root-folds and Root-fossae.

(a) The Left or Superior Root-fold and Root-fossae.
(b) The Right or Inferior Root-fold (Mesenterico-caecal Fold of Jonnesco) and Root-fossa.

3. The Caeco-appendicular Fold.

4. The Pelvic (Jonnesco) or Ilio-pelvic Colon.

(a) The M-shaped Form.
(b) The Compressed Omega Form.
(c) The Compressed and Incompletely Inverted Omega Form. (There is also (cl) an Omega (Treves) Form.)


5. The Splenic Process of Peritoneum.

(a) The Pre-splenic Part or Fold.
(b) The Sub—splenic Part or Fold.

6. The Areas of Gastric Adhesion.

(a) The Superior Area of Gastric Adhesion (“bare area”)
(b) The Inferior Area of Gastric Adhesion.

7. The Supra-adhesion Foramen. (The Spigelian Uncus (described in my “ Studies,” Part IV.) when present abuts against this foramen.)

(a) The Retro - pancreatico - duodenal Fossa.
(b) The Superior Retro-duodenal Fossa.
(c) The Intermediate, Middle, or Lateral Retro-duodenal Fossa.
(d) The Inferior Retro-duodenal F ossa (Retro-duodenal Fossa of J onnesco).

8. The Retro-duodenal Fossae.

9. The Retro-pancreatico-duodenal Recess.


  • 1 In operating for perforated astric ulcer “ the sub-diaphragmatic spaces are. especially liable to be overlooked ” (Treves, anual of Operative Surgery). “ Special attention should be directed to the space between the diaphragm and the liver on each side of the sus ensory li ament, (and) the space between the stomach and the spleen ” (Alexis Thomson an Miles, Manual of Surgery).
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Cite this page: Hill, M.A. (2024, March 28) Embryology Paper - Studies of the intestine and peritoneum in the human foetus - part 6. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Paper_-_Studies_of_the_intestine_and_peritoneum_in_the_human_foetus_-_part_6

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