Paper - Studies of the intestine and peritoneum in the human foetus - part 3

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Reid DG. Studies of the Intestine and Peritoneum in the Human Foetus: Part III. (1912) 46(4):400-415. PMID17232936

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This 1913 paper is the third 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
Modern Notes: Intestine Development

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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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Studies Of The Intestine And Peritoneum In The Human Foetus. Part III

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

Demonstrator of Anatomy in the University of Cambridge.

Studies of the Intestine and Peritoneum in the human fcetus. Part. Iii.

By DOUGLAS G. Rm, M.B., Ch.B.

Edin., B.A. Trin. Coll. Camb., Demonstrator of Anatomy in th-e University of Cambridge. ‘ I

Chiefly Concerning Various Folds of Peritoneum

Caecal Torsion and the “Bloodless” and Parieto-Colic Folds

THE “bloodless” fold of Treves may adhere to the abdominal wall and resist, for a time at all events, the completion of caecal torsion. In a foetus 229 cm. long caecal torsion is incomplete (see fig. 1).

The lamina of the mesentery to which the meso-appendix is connected is still rather anterior; the terminal part of the ileum courses to the left as Well as upwards; and the upward directed appendix crosses in front of the ascending colon and lies, in its lower part, to the right, and on the same plane as the caecum.

Passing from the mesenteric border of the appendicular caecum, and from the non-mesenteric border of the last part of the ileum, to the posterior and lateral abdominal wall, is a sheet of peritoneum. This forms the anterior wall of a fossa completely closed save below. Its orifice is bounded in front by the free lower edge of the peritoneal sheet; medially by the ileum and the adhesions (see fig. 1) which bind this down; and posteriorly and laterally by the parietal peritoneum. The -fossa extends upwards as far as the point marked + in the figure (15 cm.). As will be seen, its anterior wall is formed by the “bloodless” fold which has adhered by its usually free edge to the parietal peritoneum. I have already drawn attention to the genito-mesenteric fold as a cause of adhesion of the ileum and mesentery (see fig. 1), caecum, appendix, meso-appendix, and even “bloodless” fold of Treves, to the abdominal wall. I have a specimen showing the “bloodless” fold adhering to the genito-mesenteric fold.

The Parieto-colic Fold (Jonnesco).—This fold bounds on the right side the retro-colic fossa which is present in three out of a series of twenty foetuses (varying from 12 to 229 cm. long). It may arise in the following way.

In a foetus 18 cm. long, a large peritoneal fold (see fig. 2), containing blood-vessels, is attached to the left of the ascending colon, over the front of which it extends just above the caecum, to be attached to the parietal peritoneum to the right of the colon. It partly adheres to the front, as well as slightly to the right border of the colon. It forms the right boundary of a deep retro-colic fossa which contains the appendix, and is also the anterior wall of a pre-colic fossa 3.5 mm. deep.

This fold (see fig. 2) has practically the same relations as are presented by the parieto-colic in the adult. Thus the lower part of the right lobe of the liver is in contact with its upper part. Appendices epiploicae growing from the bowel and other parts are well developed in the smallest of the series of foetuses. In this case the parieto-colic fold is formed by what is undoubtedly a large appendix epiploica; and in this specimen there is another long appendix epiploica (see fig. 2) arising from the superior ileo-caecal (right root-) fold, and lying over the front of the colon a little below the large pre-colic fold, which has also almost reached the right border of the colon.

Fig. 1. Foetus No. XIII.

In another foetus in which the retro-colic fossa is present, the whole of the parieto-colic fold is formed in the same way, except that the appendix epiploica arises directly from the bowel, and has not acquired a secondary adhesion to it as in the first case. p Thus in two out of the three cases in which the retro-colic fossa is ‘ present, the parieto-colic fold is formed by a large appendix epiploica. In connexion with this the relations which the appendicular caecum and other parts bear to the colon behind which the retro-colic fossa is developed at a stage of caecal torsion (such as is shown in two of the foetuses examined) are interesting. In these (see fig. 3) coils of small intestine lie in front of the colon, below the part covered in front by the liver. Laterally lies the appendix, which forms a loop at the side of the colon and caecum, with its convexity directed forwards. This, with the mesoappendix, completely separates the colon from the side wall of the abdomen. At this stage of caecal torsion it appears to be impossible for any adhesion to form between the colon and lateral abdominal wall save in the manner just described. A little further torsion and the appendix becomes definitely retro-colic, and may remain in this position if the genito-mesenteric fold, or the adhesions which this produces, be present and obstruct the passage of the appendix towards its usual place on the inner side of the caecum.

Fig. 2. Fcetus No. XIV. The arrow indicates the orifice of a pre-colic fossa behind the fold of peritoneum Round ligament

Various stages of rotation through which the bowel passes in the production of a retro-colic fossa containing the appendix are illustrated in these foetuses (see figs. 1, 2, 6, and 3)

Fig. 3. Foetus No. XVIII. Part of the side wall of the abdomen has been removed.

The medial boundary of the retro-colic fossa is not always formed by the genito-mesenteric fold. This is seen, e.g., in a foetus where the last part of the ileum and the corresponding mesentery adhere to the posterior abdominal wall forming the medial boundary. Here the genito-mesenteric sheet lies to the left of the fossa.

The folds of peritoneum, in the region of the caecum, may be tabulated as follows:

(1) The genito-mesenteric fold (see figs. 2, 3, 4, 6, 7).

(2) The right root-fold, continuous with the left root-fold (see figs. 2, 5).

(3) The “bloodless” fold of Treves. In foetus xiii. (fig. 1) this is adherent to the abdominal wall, and has become relatively enormous through stretching during the descent of the caecum.

  • 1 A good description of ceecal torsion from a comparative anatomy point of view is to be found in HunLington’s book on the peritoneum.

This adhesion, together with the adhesions (see fig. .1) produced in association with the genito-mesenteric fold, resists the completion of caecal torsion.

(4) The parieto-colic fold (fig. 2).

(5) The great omentum. This I found in a full-time foetus attached to the ascending colon along its entire length and to the front of a completely descended caecum as far as the root of the appendix.

Fig 4. Diagram constructed from two specimens to show the four folds of peritoneum connected to the appendix. The right root-fold is not prolonged on to the appendix either in the adult or in the foetus. It may be continuous in the foetus with the left root-fold, so that we get a single fold along the line of which is the root of the mesentery. The genito-mesenteric fold may be connected below to the genital gland in the foetus in both sexes. It may fail to reach the genital gland, however, and may also fail to reach the ovary in the adult. It is also to be found in the adult male, when it may pass from the appendix-—a secondary connexion, or from the mesentery—the primary condition. It may form the inner boundary of a retro-colic fossa. A connexion with the ileum is also found; and the ileum through it may be very closely bound to the ovary.

(6) A muscular caeco-appendicular fold (fig. 4) passing from the front of the caecum to the appendix.

The four folds of peritoneum (see fig. 4) which may be attached to the appendix are (1) The meso-appendix. . (2) The ileo-appendicular fold of J onnesco (“bloodless ” fold of Treves). (3) The genito-mesenteric fold. This attachment to the appendix is brought about secondarily; and the lymphatics of the appendix may then be connected with those of the ovary—a point of gynaecological interest. (4) The caeco-appendicular fold (described in another paper). Since describing it I have met With it again in the adult. The Great 0mentum.—The right omental process is late in appearing. It is entirely undeveloped in a foetus 127 cm. long. The right, perfectly free, and distinct border of the great omentum (see fig. 5) crosses the colon directly below the pylorus, and passes into the right edge of the very welldeveloped infra-colic part of the omentum. In the same foetus the suspensory ligament of the spleen is Well developed (see fig. 5). As already mentioned, the right omental process, When it develops, may sometimes grow over and become adherent to the right surface of the genito-mesenteric fold, and extend thence even on to the posterior abdominal wall. In the other foetuses the right process is attached (see fig. 6) to the colon, sometimes opposite, but usually a few millimetres to the right of the right border of the second portion of the duodenum. In the smallest foetus, however, the great omentum extends along the colon to a much greater extent, reaching as far as the caecum which lies in front of the right kidney; and in a full-term foetus is attached as low down as the root of the appendix of a completely descended caecum.

Fig. 5. Foetus No. II. (12'7 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 fuetus 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). See also footnote to fig. 6.

In several foetuses the great omentum presents remarkable adhesions.

Thus in a foetus 17 cm. long, the posterior (direct) and the anterior (reflected) laminae of the great omentum have become firmly adherent, and the posterior (direct) lamina is fused completely to the colon, and to the antero-superior surface of the transverse mesocolon. This adhesion (see fig. 6) involves the whole of the colic and supra-colic portions of the great omentum except in the immediate neighbourhood of the spleen. The great omentum is only recognisable in this region and below the colon. Nor can it be dissected up from the bowel apart from the peritoneal tunic and the exposure of the muscular coat. That it had passed over the colon is recognised byvthe presence of branches of the gastro-epiploic arteries which cross the front of the bowel (see fig. 6), and by the presence of the infra-colic portion of the great omentum. The adhesion (see fig. 6) reaches as far as the greater curvature of the stomach, and is continuous here with the inferior area of gastric adhesion to be described later. The fusion extends along the greater curvature from the pylorus to a point 8 mm. from this; and to the left of this point its upper border lies immediately below the greater curvature for about another 8 mm. Practically as great solidity of fusion is seen in several other foetuses (see fig. 7). But in the region of the spleen the supra-colic and colic portions are always distinct, and the lesser cavity of peritoneum intact (see figs. 6 and 7). Therefore even in a young child it would be advisable, should the surgeon desire to open into the lesser sac by an incision along the greater curvature of the stomach, to make that incision in the neighbourhood of the spleen.

Fig. 6. Foetus No. VIII. The stippling indicates areas of adhesion. In this and all the other foetuses the meso-duodenum to the right of the pylorus is completely covered by the transverse colon and the mesentery of the intestinal loop. The figures and descriptions given in the books dealing with the development of the peritoneum are inaccurate in this respect.

The firm resistance of the large liver is to be kept in mind in accounting for this apparent absence through fusion of the right part of the great omentum.

There is sometimes present a diverticulum of the great omentum which has not been noted hitherto. In several foetuses the great omentum (which is early developed opposite the stomach) sends downwards a process behind or (at first) to the left of the descending colon and mesocolon before these have fused over the front of the kidney. Thus in a foetus 6'7 cm. long there is a diverticulum of the great omentum which ‘descends in front of the left kidney to a point about 5 mm. below the pancreas and near to the lower extremity of the kidney. Over this the colon and mesocolon would subsequently become soldered down.

It is therefore possible that the pre-renal fascia over a part of the left kidney below the pancreas may be of more complex origin than hitherto recognised, the left kidney having in front of it there the connective tissue of the parietal peritoneum, of the two layers of the great omentum, and of the mesocolon.

The Suspensory Ligament of the Spleen

In no case does the anterior basal angle of the spleen rest upon the phreno-colic ligament. It is placed medial, or in front and medial to this ligament, and in one foetus (122 cm. long) liesbehind it. In this foetus the left lobe to the liver covers the whole length of the “diaphragmatic” surface of the spleen, and lies below, in front of the spleen, in contact with the upper surface of the ligament.

The suspensory ligament may be well developed although the splenic flexure does not lie below it (see fig. 5). y There is absence of the phrenocolic ligament in foetuses measuring 145, 193, 218, and 228 cm. in length. It is also absent in a foetus 6'7 cm. long, in which the right omental process had just begun to appear.

A fold of peritoneum is present in 90 per cent. of foetuses attached to the greater curvature of the stomach _ in front of the gastro-splenic omentum, the attachment extending in some cases to practically the highest point. of the stomach. Although not hitherto described, it is also seen in the adult. This, which may be called the “ pre-splenic ” fold, is not to be confused with a less common fold (Which is also present in one foetus) passing from the anterior surface of the stomach, at some distance from the greater curvature, into the great omentum.

Fig. 7. Foetus No. X. (16'8 cm. long). The spleen has been removed to show the upper surface of the sub-splenic fold which is distinct from Toldt’s (“ the suspensory”) ligament.

The pre-splenic fold (see figs. 5, 6, 7, and 8) passes over the anterosuperior border of the spleen and comes to lie between the liver and the diaphragm, to which it never adheres, on the one hand, and the diaphragmatic surface of the spleen on the other (see fig. 8). Its splenic lamina is continuous with the “external peritoneum” of the gastro-splenic omentum (see fig. 8), and it sometimes exceeds 1 cm. in height. In some cases it is continued below into a sub-splenic fold of peritoneum which is directed outwards towards the diaphragm, to which it sometimes adheres. This fold (see fig. 7) is placed between the basal surface of the spleen above, and the colon and phreno-colic ligament below. It presents a superior and an inferior surface, an anterior and a posterior border. The anterior border is continuous (see fig. 7) with the free border of the pre-splenic fold, and always follows the line of the inferior border of the spleen. The posterior border may be placed well under cover of the spleen. It lies quite 6 mm. in one case from the anterior part of the inferior border of the viscus. The left extremity reaches close to the diaphragm and may adhere to it.

Fig. 8. Transverse section of a foetus 15'5 cm. long (vertex-coccygeal measurement). One and a half times the actual size. The arrow indicates the position of the foramen (of Huschke) below the free edge of the plica gastro-pancreatica (part of the septum bursarum omentalium of Huschke). The right end of the arrow lies in the recessus superior omentalis (the part of the lesser sac of peritoneum behind the Spigelian lobe). The left end lies in the recessus inferior omentalis (the part of the lesser sac behind the stomach and extending downwards into the great omentum). The spleen, of course, does not normally adhere to the suprarenal capsule. It is interesting to compare this section with those, especially fig. 4, of Swaen (Bibliographic Anaiomique, tome vii.), of embryos showing the development of the lesser sac of peritoneum.

In two of the cases in which this fold is present there is no phreno-colic ligament, and the free left margin of the great omentum is crossed below the spleen by the free posterior margin of this sub—splenic fold.

In another case where there is a relatively large sub-splenic fold, which adheres to the diaphragm, there is also a well-formed phreno-colic ligament, answering to the usual descriptions, passing between the upper part of the descending colon and the diaphragm.

The posterior border of the sub-splenic fold is here united to the peritoneum of the great omentum under cover of the spleen. There are thus two suspensory ligaments: a superior, in close opposition with the basal surface of the spleen; and an inferior (phreno-colic ligament of Toldt), completely separated from the spleen.

I Below the superior suspensory ligament is the great omentum united to the splenic flexure, and coursing towards the phreno-colic ligament into which it passes.

In another foetus a well-developed suspensory ligament is present, formed entirely by the sub-splenic fold. The free left border of the great omentum lies below it, and at quite a distance from the costal diaphragm. In some foetuses there is a trace of the sub-splenic fold, although in most cases it is of little depth.

The anterior basal angle of the spleen lines in the angle between these pre- and sub-splenic folds. The ligament of Hensing is not to be confused with the inferior suspensory ligament of the spleen. Traction upon the surrounding peritoneum quite fails in every case to cause any obliteration of the parts of the splenic process. Apart from support obtained through the suspensory ligament the spleen, in two cases, adheres to the peritoneum covering the left suprarenal body (see fig. 8), with which in the foetus the spleen is in contact above the level (see fig. 8), as Well as in front of the upper part of the kidney. In the latter situation therefore the suprarenal body separates the kidney from the spleen, which as yet has no surface properly termed renal. In the adult the renal surface of the spleen may sometimes be found adherent to the left kidney. This and other adult variations of the peritoneum in relation to the spleen are figured and described in Poirier’s Anatomy (p. 986,- vol. iv., 1905). In one foetus the basal surface of the spleen adheres firmly to the splenic flexure,‘ and in another the phreno-colic ligament is formed by an appendix epiploica which has fused to the diaphragm and is independent of the free left margin of the great omentum. I

There is a tendency therefore towards the development of a ligament especially associated with the support of the basal surface of the spleen. An association of the phreno-colic ligament of Toldt with the liver appears to precede its association with the spleen, which is not shown in any of the foetuses.

The sub-splenic fold exhibits a tendency to fuse with the peritoneum upon the colon, and it thus may become completely or partially obliterated. Studies of the Intestine and Peritoneum in the Human Foetus 411

In addition, therefore, to the phreno-colic ligament of Toldt the spleen may have the following peritoneal supports :- —

(1) A sub-splenic fold.

(2) Adhesion of the spleen to the suprarenal capsule or kidney.

(3) Adhesion of the spleen to the splenic fiexure.

A suspensory ligament formed by an appendix epiploica.

According to Toldt the right process of the great omentum develops in the seventh month and the left process in the fifth.

But the right process maybe present in a foetus 12 cm. long, and the suspensory ligament may be quite undeveloped in several older foetuses. or may be formed entirely by the sub-splenic fold. The splenic process appears obviously to be developed (see fig. 8) from the “external peritoneum” of the gastro—splenic omentum. Indeed, it is to be seen projecting outwards as a duplication of this peritoneum. Its laminae are always soldered closely together.

il[<)(Zific(1.h'()ns of Me ’1lrcm._s'2*elr.s'e Colon, (mcl flee Pylon)-colic:

Fold aoul F08.s'('L.

Since describing the pyloro-colic fold ‘I have found that a ligament has been described in the adult under the same name. “ Glénard a décrit sous le nom de ligament pylori-colique une attache résistante et constante qui suspendrait la partie moyenne du colon a la grande courbure de l’esto1nac au niveau du canal pylorique. Ce ligament n’a pas été retrouvé par les observateurs qui l’ont recherché (F romont, Mauclair, Buy). L’attache épiploique au niveau du pylore ne présente pas de forme particuliere” (Jonnesco and Charpy, p. 348, vol. iv., Poirier’s Aamtrnny, 1901).

But a pyloro-colic fold and fossa may be found in the foetus.

The orifice of the fossa is directed upwards and to the left, and is bounded in front by the free edge of a pyloro-colic fold (see figs. 6 and 7) which is not arterial, and is usually quite tightly stretched as if it were helping to support the colon, although indeed it often does not gain any definite attachment to this. It extends from the pylorus to, or towards, the adjacent right extremity of the left colic loop (see fig. 7). The fossa may attain a depth of 1 mm., or even more, and i.ts walls are lined by the great omentum, which in most of the cases is adherent to the Walls of the fossa.

How may the fold be produced?

The transverse colon opposite the stomach forms a loop, the left colic loop of J onnesco (see figs. 6 and 7), which, propped up by the coils of small intestine, is directed more or less horizontally forwards.

A plication of the mesentery of this loop may occur. Thus the right limb of the loop has been rotated towards the left limb in nine cases; and this is accompanied by a folding, about an artery (ascending terminal branch of the right colic, or left terminal branch of the middle colic), of both endothelial laminae of the mesocolon passing to the right limb. This plication has produced a shelf of peritoneum lying below the right limb of the left colic loop (see fig. 9). The upper surface of this fold in one case is free (fig. 9, A); in the others it has fused to the colon (fig. 9, B). The result of this plication is that the limbs of the left colic _l_oop have become more closely opposed—and permanently so as the result of the adhesion of the fold to the colon and of the parts forming the fold to one another (see fig. 9). Certain of the “remarkable bends that are sometimes formed by this part of the bowel” (Treves, Morris’s Anatomy, 1902, and Hunterian Lectures) are the result of this movement to the left and headwards of the right limb of the left colic loop of the transverse colon. The limbs of the loop may become closely opposed, and a primitively U-shaped left colic loop may .thus become secondarily V-shaped. The shelf and the pyloro—colic fold is present in all the cases in which the rotation of the right limb of the colic loop had occurred with the formation of a distinct sub-colic peritoneal shelf- It is absent in all the foetuses in which there is no shelf. The shelf and the pyloro—colic fold are thus correlated variations.

Fig. 9. This figure illustrates the fact that normal endothelial surfaces can adhere to one another; and the appearances cannot be accounted for by the displacement theory.

The rotation which produces the sub-colic fold produces also a plication of the great omentum in the neighbourhood of the pylorus; for the colon, which lies opposite this and the first part of the duodenum, is also caused to rotate to a greater or less extent.

fig. 9 illustrates in a simple way how normal endothelial surfaces can adhere to one another, and how the adhesion cannot be accounted for by the displacement theory. Three stages are illustrated in this figure. In the firststage (A) there is a fold with free surfaces and containing an artery. In the second stage (B) the upper surface of the fold has adhered to the colon. finally, the artery may retract from the fold, third stage (C). I have found other equally apparent proofs of the occurrence of adhesion together of normal endothelial surfaces in almost every foetus I examined. There are other modifications of the transverse colon. The right limb of the right colic loop (see fig. 7) may be more closely approximated to the left limb by rotation. Plications of the mesocolon containing the left colic artery are practically confined to the region of the spleen; and I have noted that the splenic flexure, which normally (His and Toldt) corresponds to the splenic flexure of the embryo, appears in a few cases to be produced by a rotation upwards of a part of the colon. of the intestinal loop. The development of the sub-splenic fold may possibly be a correlated variation. The elongation of the transverse colon, then, is associated often with the production of movements which are of the nature of torsions about blood-vessels. What are presumably the latest torsions are always in a partly headward direction, the more primitive (the transverse mesocolon hangs downwards) being away from the liver.

The Mesentery of the Terminal Intestine

The terminal intestine (J onnesco) is the portion of the large intestine which extends from the splenic flexure to the “anus.”

As regards the lower limit of fusion (position of the root of the iliacpelvic colon) of the terminal mesentery to the parietal peritoneum, I have noted no marked sexual differences.

In one foetus which I examined, the mesentery of the terminal intestine is still attached along the middle line, but has turned so that its right surface has become posterior, although in the region of the splenic flexure it has turned in the opposite and usual direction. The inferior mesenteric artery arises from the right side of the aorta. In an adult the terminal intestine had the same direction and position as in this foetus (see fig. 5). It coursed downwards and to the right from the splenic flexure, and crossed the abdominal aorta to reach the right iliac fossa, where a loop was formed, as is also the case in the foetus. Thence the bowel was continued downwards upon, and attached to, the right wall of the true pelvis. The mesentery was fused down over the obliquely directed colon, and the inferior mesenteric artery had its place of origin upon the front and right aspect of the abdominal aorta.

There is a slight tendency, then, for the more caudally situated portion of the terminal mesentery to place itself so that its right surface becomes posterior.

In the foetus the lower part of the terminal mesentery has not adhered to the posterior abdominal wall, except that a long fossa is present behind the descending colon bounded by mere linear areas of adhesion.

I have noted the occurrence both in foetuses and in the adult of a short antero-posteriorly directed loop upon the upper portion of the descending colon. It may be termed the sub-splenic loop of the descending colon.

The Hepato-Colic Ligament (O'yst0-col'ic) Lt’;/ctmcnt (Husch/cc).

This ligament, about which much has been written, is present in six out of twenty foetuses (30 per cent.). Addison (._/om°i7u.z.l of A/m;u‘omy (L’I’L~(l Physiology, vol. xxxv. p. 200) found it present in the same percentage of adults. Bricon(Lr_a1"rog7°és illédical, 1888, to1ne vii. p. 27) extricates this fold from oblivion, as he puts it, on account of its alleged importance in cholecystotomy and cholecystectomy, a11d because he says it explains how biliary calculi may be “ éliminés avec facilité par le colon. C’est pour eux un chemin tout trace et, pour le calculeux (lui est possesseur de ce repli, une disposition heureuse qui lui évite les plus dangereuses des complications.” He supports this statement by so1ne clinical evidence, Thiriar having found biliary calculi under the peritoneum in the neighbourhood of the colon.

According to Bricon the continuity between the hepato-colic ligament and the great omentum results from the fusion of the right process of the latter structure with the ligament.

Ancel and Sencert (BIi])li()g7’((])]L'7i6 A‘7l(.'tI‘()1)li?i(]ZL(_’, 1903, tome xii. pp. 1 and 102) assert that the continuity is primitive. “La continuité de son feuillet antérieur avec le grand epiploon prolongé par l’epiploon colique de Haller est primitive et 1’on ne doit pas y voir lo résultat d’une soudare secondaire.”

But I have seen a case (see fig. 7) in which the two structures appear to have been, as far as can be judged, separate from the first. In this foetiis the right omental process appears not to have been developed, and the right edge of the great omentum falls a long distance short of the ligament. I find also that Buy (B/ibliogmp/z.~ic Amztoiiimlqizw, tome xii. p. 64) notes the same disposition. “J ’accepterais volontiers l’l1ypothese ingenieuse d’Ance1 si la description qu’il donne se vérifiait chez les foetus et les nouveau-nés. Or, si pareille disposition se rencontre chez l’adulte—il ne n1’a jamais éte’ donné la constater chez les nouveau-nés, oh le bord droit du grand epiploon s’arr€~te £1. une distance assez marquee do l’insertion du cystico-colique sur le colon transverse.”

Tripier and Paviot (Bibl*£0g7°cLpIz.ic Amcto~7iLiq?Lc, tome xii., p. 139) favour Studies of the Buy’s statements. Poirier (Anatomy, p. 994, vol. iv.) appears to favour the views of Ancel and Sencert.

In some cases, Where the small omentum extends unusually far towards the right (see fig. 7), the colon may come practically, if not into actual contact With it, and the evidence I have at present is in favour of the view of Bricon. A mesocyst is present in one in twenty foetuses (5 per cent.).

In this paper, besides describing various arrangements, I have drawn attention to adhesions to the parietal peritoneum of the bloodless fold of Treves along its usually free edge, of appendices epiploicae, and of colon along almost immeasurably small linear areas. I have also noted a colon which has adhered to folds of its own mesentery. Is it “ a local displacement of the peritoneal layers” (Byron Robinson, “ Morphology of the Digestive Tract,” Jowrnal of Anatomy and Physiology, vol. xxxiii.)-—owing to irregularities of surrounding growth—that produced the fossa, bounded by almost mere lines of adhesion, Which I have described (Journal of Anatomy and Physiology, vol. xlii.) in an adult behind the entire mesocolon? Has this caused a loop of intestine in a foetus 25 mm. long to adhere to the right surface of the still mesial mesentery of the intestinal loop as I have noted? Has it caused the genito-mesenteric fold to adhere by its right surface to the posterior abdominal Wall when it was pressed upon by the colon, as has been noted? I have given, and can give, numerous further illustrations of the apparent insufficiency of the “ displacement” theory to explain certain facts.

Cite this page: Hill, M.A. (2024, May 28) Embryology Paper - Studies of the intestine and peritoneum in the human foetus - part 3. Retrieved from

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