Difference between revisions of "Paper - A contribution to the development of the prostate in man"

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{| class="wikitable mw-collapsible mw-collapsed"
=A Contribution to the Development of the Prostate in Man=
+
! Online Editor Note 
ic EA CONTRIBUTION TO THE DEVELOPMENT OF THE PROSTATE
+
|-
IN MAN. By EVELYN JOHN EVATT, University College, Cardifi”.
+
| [[File:Mark_Hill.jpg|90px|left]] This historic 1909 paper by Evatt is an early description of male prostate development.
  
IN connection with this contribution I desire to thank Professor’
+
See also - {{Ref-Evatt1911}}
  
Wiedersheim of the Anatomical Institute, Freiburg in Breisgau, for the
+
{{Ref-Lowsley1912}}
generous way in which he placed the facilities of his department at my
 
disposal;'and I also wish to acknowledge my indebtedness to Professor
 
Keibel for the very helpful advice I received from him during the construction of a wax-plate model of the glandular tissue of the prostate. The
 
following conclusions regarding the development of the prostate have been
 
arrived at chiefly from a study of this model and of the sections from
 
which the model was built up.
 
  
The foetus from which the prostate Was taken was said to be three and
+
{{Ref-Spaulding1921}}
a half months old. It measured 12 cm. from vertex to coccyx. The foetus
+
<br>
was injected through the umbilical vein with a_ 10 per cent. solution of
+
<br>
formalin. The sections, which were 12 micro-millimetres thick, were
+
'''Modern Notes:''' [[Genital System Development]] | [[Fetal Development]]
stained with picrocarmine. The model represents a magnification of 64.
+
<br>
When the model was fully constructed it was split down, just a little to
+
{{Genital Links}}
the left of the middle line, so as to leave the anterior ducts associated
+
|}
with the right half. The short transverse lines in figs. 2 and 3 indicate
+
{{Historic Disclaimer}}
the plane along which it was split. In the model the ducts represent the
+
=A Contribution to the Development of the Prostate in Man=
Whole thickness of the epithelial walls of the original ducts. This was done
+
By Mr Evelyn John Evatt, University College, Cardiff.
because one could not always recognise the lumen of every duct, and further,
 
because the outline of the epithelial buds was sharply demarcated from the
 
surrounding tissues, and could therefore be accurately traced. In the case of
 
the prostatic urethra the inner wall was traced, so that the model represents,
 
as it were, a cast of the inside of the prostatic urethra with the prostatic
 
ducts in their whole thickness attached to it.
 
 
 
In the course of this paper I shall suppose the foetus to be in the
 
anatomical posture, and employ the terms superior and inferior, anterior
 
and posterior, in the sense in which they are used nowadays.
 
  
The prostatic urethra at this stage of development, three and a half
+
* In connection with this contribution I desire to thank Professor Wiedersheim of the Anatomical Institute, Freiburg in Breisgau, for the generous way in which he placed the facilities of his department at my disposal; and I also wish to acknowledge my indebtedness to Professor Keibel for the very helpful advice I received from him during the construction of a wax-plate model of the glandular tissue of the prostate. The following conclusions regarding the development of the prostate have been arrived at chiefly from a study of this model and of the sections from which the model was built up.
months, consists of two parts: (1) an upper fourth, and (2) a lower threefourths (figs. 2 and 3, U.S. and L.S.). Just near the neck of the bladder the
 
urethra has the shape indicated in fig. 5 on transverse section; a little lower
 
down it takes on the form seen in fig. 6. These two outlines represent the
 
form of the upper fourth of the urethra at its upper and lower ends.
 
' A Contribution to the Development of the Prostate in Man 315
 
  
Different views of the two halves of a wax-plate model of the rostatic urethra and glandular tissue of the
 
prostate. The short transverse lines in figs. 2 and 3 in icate the plane along which the model was
 
split. Figs. 1 and 2, outer and inner surfaces of the right half respectively. Figs. 3 and 4, inner and
 
outer surfaces of the left half respectively.
 
  
U.S., up r subdivision ; L.S., lower subdivision: U., urethra; A.D., anterior ducts ; I.lI.D., inferior horizontal ducts;
 
3r L.D.. ducts of the “3rd lobe ”; W.D., Wolflian ducts; V.S., vesicular seminnles ; M.D., Miillerian ducts.
 
316 Mr Evelyn John Evatt
 
  
THE LOWER SUBDIVISION OF THE PROSTATIC URETHRA is spur-shaped on
+
The foetus from which the prostate was taken was said to be three and a half months old. It measured 12 cm. from vertex to coccyx. The foetus was injected through the umbilical vein with a 10 per cent. solution of formalin. The sections, which were 12 micro-millimetres thick, were stained with picrocarmine. The model represents a magnification of 64. When the model was fully constructed it was split down, just a little to the left of the middle line, so as to leave the anterior ducts associated with the right half. The short transverse lines in figs. 2 and 3 indicate the plane along which it was split. In the model the ducts represent the Whole thickness of the epithelial walls of the original ducts. This was done because one could not always recognise the lumen of every duct, and further, because the outline of the epithelial buds was sharply demarcated from the surrounding tissues, and could therefore be accurately traced. In the case of the prostatic urethra the inner wall was traced, so that the model represents, as it were, a cast of the inside of the prostatic urethra with the prostatic ducts in their whole thickness attached to it.
transverse section (fig. 7); the difference in shape is associated with the
 
presence of the crista urethralis in the lower three-fourths.
 
  
The Wolffian and Miillerian ducts (genital cord) enter the lower subdivision at the junction of its upper and middle thirds (figs. 2 and 3, M.D.
 
and W.D.) ‘
 
  
The arrangement of the ducts arising from the lower subdivision.
+
In the course of this paper I shall suppose the foetus to be in the anatomical posture, and employ the terms superior and inferior, anterior and posterior, in the sense in which they are used nowadays.
  
Four ducts grow out from the anterior limb of the urethra; they are all
 
directed upwards, and do not branch (figs 1 and 2, AD.).
 
  
+
The prostatic urethra at this stage of development, three and a half months, consists of two parts: (1) an upper fourth, and (2) a lower threefourths (figs. 2 and 3, U.S. and L.S.). Just near the neck of the bladder the urethra has the shape indicated in fig. 5 on transverse section; a little lower down it takes on the form seen in fig. 6. These two outlines represent the form of the upper fourth of the urethra at its upper and lower ends.
  
FIG. 5.—Section through the prostate and genital cord at the
+
[[File:Evatt1909 fig01-04.jpg|600px]]
upper end of the “ upper subdivision ” of the prostate.
 
  
Pr., prostate; G.C., genital cord ; U., cavity of the urethra ; A.D., P.D.,
 
  
L.D., anterior posterior, and lateral prostatic ducts respectively;
+
Different views of the two halves of a wax-plate model of the rostatic urethra and glandular tissue of the prostate. The short transverse lines in figs. 2 and 3 in icate the plane along which the model was split.  
W. D. (V .S.), Wolfilan ducts(vesicu1aa seminales).
 
  
The ducts which come off from the bottom of the prostatic sinus are
+
Figs. 1 and 2, outer and inner surfaces of the right half respectively. Figs. 3 and 4, inner and outer surfaces of the left half respectively. U.S., up r subdivision ; L.S., lower subdivision: U., urethra; A.D., anterior ducts ; I.lI.D., inferior horizontal ducts; 3r L.D.. ducts of the “3rd lobe ”; W.D., Wolflian ducts; V.S., vesicular seminnles ; M.D., Miillerian ducts.
nine in number on each side; they arise at intervals along its whole length ;
 
they pass backwards for a short distance, and then turn upwards, branching
 
frequently and irregularly. The upper ones are larger and more branched
 
than the lower, being apparently in a more advanced stage of development
 
(figs. 1 and 4:).
 
  
Seven ducts pass out from the outer wall of each sinus; the more anterior
 
of these are unbranched (figs. 1 and 4:). They all pass upwards.
 
  
Three ducts, the inferior horizontal, arise from the internal wall of
+
The lower subdivision of the prostatic urethra is spur-shaped on transverse section (fig. 7); the difference in shape is associated with the presence of the crista urethralis in the lower three-fourths.
each sinus, below the point of entrance of the genital cord; they pass
 
directly backwards, branching frequently (figs. 2 and 3, I.H.D.). They
 
‘A Contribution to the Development of the Prostate in Man 317
 
  
are remarkable in that they are the only ducts which do _ not pass
+
The Wolffian and Miillerian ducts (genital cord) enter the lower subdivision at the junction of its upper and middle thirds (figs. 2 and 3, M.D. and W.D.) ‘
upwards.
 
N o ducts grow out from the summit of the crista urethralis.
 
  
UPPER SUBDIVISION 013‘ THE PROSTATIC URETHRA (figs. 2 and 3, U.S.).
+
The arrangement of the ducts arising from the lower subdivision.
 
 
Three ducts take origin from the anterior limb or angle (figs. 1 and 2);
 
they are short, and of considerable thickness; they pass upwards and do
 
not branch.
 
 
 
 
 
 
FIG. 6.—Ti-ansverse section throu h the middle of the
 
“upper subdivision ” of t e prostate.
 
  
l-7., urethra; A.D., L.D., anterior and lateral prostatlc ducts
+
Four ducts grow out from the anterior limb of the urethra; they are all directed upwards, and do not branch (figs 1 and 2, AD.).
  
respectively ; P.D., posterior prostatic ducts (those of the
+
[[File:Evatt1909 fig05.jpg|600px]]
3rd lobe) ; W.D., Wolfllnn ducts.
 
  
Four ducts arise from the outer wall on each side; they lie in series with
+
'''FIG. 5.''' Section through the prostate and genital cord at the upper end of the “ upper subdivision ” of the prostate. Pr., prostate; G.C., genital cord ; U., cavity of the urethra ; A.D., P.D., L.D., anterior posterior, and lateral prostatic ducts respectively; W. D. (V .S.), Wolfilan ducts (vesiculae seminales).
the lateral ducts of the lower subdivision (figs. 1 and 4).
 
  
The two largest ducts of the prostate arise one from each postero—
 
external angle of the urethra (figs. 2 and 3, 3rd L.D.). They first pass downwards for a short distance and then turn upwards, branching frequently
 
and irregularly, their branches nearly touching in the middle line behind.
 
They seem to have been first observed by Henle, though later observers
 
  
apparently failed to find them. They may be termed the ducts of the
+
The ducts which come off from the bottom of the prostatic sinus are nine in number on each side; they arise at intervals along its whole length ; they pass backwards for a short distance, and then turn upwards, branching frequently and irregularly. The upper ones are larger and more branched than the lower, being apparently in a more advanced stage of development (figs. 1 and 4:).
third lobe. Two small unbranched ducts arise in series with these, and on
 
  
a higher plane, and pass upwards: there are thus fifty—nine ducts in all.
+
Seven ducts pass out from the outer wall of each sinus; the more anterior of these are unbranched (figs. 1 and 4:). They all pass upwards.
At first sight it Would seem that the anterior ducts are unpaired, and
 
318 Mr Evelyn John Evatt
 
  
were not bilaterally symmetrical, but an examination of the transverse
+
Three ducts, the inferior horizontal, arise from the internal wall of each sinus, below the point of entrance of the genital cord; they pass directly backwards, branching frequently (figs. 2 and 3, I.H.D.). They are remarkable in that they are the only ducts which do _ not pass upwards. N o ducts grow out from the summit of the crista urethralis.
sections of the prostate appears to reveal the true history of these ducts;
 
for instance, a transverse section through the middle of the prostate shows
 
two ducts springing from the anterior wall of the urethra (fig. 8, A); higher’
 
up the appearance is as in fig. 8, B ; fig. 8, C, is still higher; and finally, fig.
 
8, D, shows only one duct. These sections would seem to show that
 
originally on the right side there were ducts corresponding with those on
 
the left, and that the latter assumed a mesial position owing to the former
 
not going on to further development.
 
  
+
Upper subdivision of the prostatic urethra (figs. 2 and 3, U.S.).
  
FIG. 7. ——Transverse section through the “lower subdivision ” of the prostate in the neighbourhood of the Wolffian and Miillerian ducts.
+
Three ducts take origin from the anterior limb or angle (figs. 1 and 2); they are short, and of considerable thickness; they pass upwards and do not branch.
  
W.D., Wolflian ducts; M. D., Miillerlan ducts; U.. urethra; A.D., P.D., anterior
+
[[File:Evatt1909 fig06.jpg|600px]]
and posterior prostntic ducts respectively ; LD. and S.D.. lateral ducts.
 
  
THE LOBES or THE PROSTATE.
 
  
At first the prostatic sinuses and their ducts in the lower subdivision are
+
'''FIG. 6.''' Transverse section throu h the middle of the “upper subdivision ” of t e prostate. l-7., urethra; A.D., L.D., anterior and lateral prostatlc ducts respectively ; P.D., posterior prostatic ducts (those of the 3rd lobe) ; W.D., Wolfllnn ducts.
widely separated (figs. 7 and 8). The ducts from the bottom of each sinus,
 
together with those which grow out from the lateral walls of each sinus, may
 
be regarded as forming the lateral lobe of that sinus. The branches of the
 
ducts from the bottom and outer Wall of one sinus probably do not meet those
 
of the other side behind, though the branches of the ducts from the inner
 
walls of the sinus (the inferior horizontal ducts, figs. 2 and 3, I.H.D.) do so.
 
  
The branches of the two largest ducts (the ducts of the third lobe, figs.
+
Four ducts arise from the outer wall on each side; they lie in series with the lateral ducts of the lower subdivision (figs. 1 and 4).
2 and 3, 3rd L.D.) come together in the middle line behind, and these with
 
the two smaller ducts immediately above them form a centrally placed
 
A Contribution to the Development of the Prostate in Man 319
 
  
lobe above the level of the point of entrance of the genital cord. This is
+
The two largest ducts of the prostate arise one from each postero— external angle of the urethra (figs. 2 and 3, 3rd L.D.). They first pass downwards for a short distance and then turn upwards, branching frequently and irregularly, their branches nearly touching in the middle line behind. They seem to have been first observed by Henle, though later observers apparently failed to find them. They may be termed the ducts of the third lobe. Two small unbranched ducts arise in series with these, and on a higher plane, and pass upwards: there are thus fifty—nine ducts in all. At first sight it Would seem that the anterior ducts are unpaired, and were not bilaterally symmetrical, but an examination of the transverse sections of the prostate appears to reveal the true history of these ducts; for instance, a transverse section through the middle of the prostate shows two ducts springing from the anterior wall of the urethra (fig. 8, A); higher’ up the appearance is as in fig. 8, B ; fig. 8, C, is still higher; and finally, fig. 8, D, shows only one duct. These sections would seem to show that originally on the right side there were ducts corresponding with those on the left, and that the latter assumed a mesial position owing to the former not going on to further development.
the third lobe; it consists of ducts derived from both sides of the prostate,
 
and cannot therefore be regarded as an azygos structure.
 
  
Development of the Ducts.——Certain of these are formed by a pinching
+
[[File:Evatt1909 fig07.jpg|600px]]
oil" of a portion of the urethral lining membrane in its long axis. This
 
fold or tuck eventually separates from the urethra, except at its lower end,
 
where it remains attached to, and in communication with, the urethra: the
 
  
I
+
'''Fig. 7. T'''ransverse section through the “lower subdivision ” of the prostate in the neighbourhood of the Wolffian and Miillerian ducts. W.D., Wolflian ducts; M. D., Miillerlan ducts; U.. urethra; A.D., P.D., anterior and posterior prostntic ducts respectively ; LD. and S.D.. lateral ducts.
I
 
  
A.D.
+
==The Lobes of the Prostate==
4
 
  
I
+
At first the prostatic sinuses and their ducts in the lower subdivision are widely separated (figs. 7 and 8). The ducts from the bottom of each sinus, together with those which grow out from the lateral walls of each sinus, may be regarded as forming the lateral lobe of that sinus. The branches of the ducts from the bottom and outer Wall of one sinus probably do not meet those of the other side behind, though the branches of the ducts from the inner walls of the sinus (the inferior horizontal ducts, figs. 2 and 3, I.H.D.) do so.
  
1
+
The branches of the two largest ducts (the ducts of the third lobe, figs. 2 and 3, 3rd L.D.) come together in the middle line behind, and these with the two smaller ducts immediately above them form a centrally placed lobe above the level of the point of entrance of the genital cord. This is the third lobe; it consists of ducts derived from both sides of the prostate, and cannot therefore be regarded as an azygos structure.
  
I
+
==Development of the Ducts==
  
     
+
Certain of these are formed by a pinching oil" of a portion of the urethral lining membrane in its long axis. This fold or tuck eventually separates from the urethra, except at its lower end, where it remains attached to, and in communication with, the urethra: the process of separation begins at the upper end. Ducts developed in this manner possess a lumen from the outset.
  
FIG. 8.—A, B, C, D, a series of the. transverse sections through the
 
“lower subdivision” of the prostate, passing in that order from
 
below upwards. ‘
 
  
A.D., anterior ducts; Pr.S., prostatic sinus.
+
[[File:Evatt1909 fig08.jpg|600px]]
  
process of separation begins at the upper end. Ducts developed in this
+
'''Fig. 8.''' A, B, C, D, a series of the. transverse sections through the “lower subdivision” of the prostate, passing in that order from below upwards. A.D., anterior ducts; Pr.S., prostatic sinus.
manner possess a lumen from the outset.
 
  
With reference to the development of the prostatic ducts, Pallin observes
 
“so betrachte ich es als im hochsten Grade Wahrscheinlich, obschon nicht
 
ganzlich bewiesen, dass auch diese hinteren und demnach alle menschlichen
 
Prostatadriisen durch Abschniirung \'OIl longitudinalen Falten an der
 
Urethralwand angelegt werden ” (p. 142, Archie fitr Anatomie, 1901).
 
  
As regards the ducts which pass up and do not branch, Pallin’s statement
+
With reference to the development of the prostatic ducts, Pallin observes “so betrachte ich es als im hochsten Grade Wahrscheinlich, obschon nicht ganzlich bewiesen, dass auch diese hinteren und demnach alle menschlichen Prostatadriisen durch Abschniirung \'OIl longitudinalen Falten an der Urethralwand angelegt werden ” (p. 142, Archie fitr Anatomie, 1901).
of their mode of origin is probably correct. The inferior horizontal ducts
 
(figs. 2 and 3, I.H.D.), which Pallin does not seem to have observed, and the
 
320 Mr Evelyn John Evatt
 
  
large ducts of the third lobe, cannot have been separated as longitudinal
+
As regards the ducts which pass up and do not branch, Pallin’s statement of their mode of origin is probably correct. The inferior horizontal ducts (figs. 2 and 3, I.H.D.), which Pallin does not seem to have observed, and the large ducts of the third lobe, cannot have been separated as longitudinal folds.
folds.
 
  
I have not been able to satisfy myself that any of the prostatic ducts
+
I have not been able to satisfy myself that any of the prostatic ducts grow out as“ solid buds.” On the contrary, I am inclined to believe that even at the distal end of a given duct the presence of a lumen can be postulated from the radial disposition of the cells lining the duct.
grow out as“ solid buds.” On the contrary, I am inclined to believe that even
 
at the distal end of a given duct the presence of a lumen can be postulated
 
from the radial disposition of the cells lining the duct.
 
  
The Miillerian ducts coalesce for a short distance before entering the
+
The Miillerian ducts coalesce for a short distance before entering the posterior wall of the urethra upon the summit of the crista, between the Wolflian ducts ; they then extend backwards as a bicornuate structure. The left cornu as compared with the right is enormously developed and flattened from side to side; it extends above and below the right, which is small and flattened from above downwards (fig. 2, M.D.). At three and a half months the Miillerian ducts enter the urethra at right angles to its long axis; at birth it is seen to enter obliquely from above downwards and forwards.
posterior wall of the urethra upon the summit of the crista, between the
 
Wolflian ducts ; they then extend backwards as a bicornuate structure. The
 
left cornu as compared with the right is enormously developed and flattened
 
from side to side; it extends above and below the right, which is small and
 
flattened from above downwards (fig. 2, M.D.). At three and a half months
 
the Miillerian ducts enter the urethra at right angles to its long axis; at
 
birth it is seen to enter obliquely from above downwards and forwards.
 
  
The Wolffian ducts are also seen to enter the urethra at right angles to
+
The Wolffian ducts are also seen to enter the urethra at right angles to its long axis and in the same horizontal plane with the Miillerian ducts.
its long axis and in the same horizontal plane with the Miillerian ducts.
 
  
The vesiculae seminales are observed growing out from the Wolflian
+
The vesiculae seminales are observed growing out from the Wolflian ducts as small, sac—shaped diverticula; at three and a half months they lie in the genital cord outside the prostate (figs. 1, 2, '3, 4, and 5). It is only with the further development of the latter that they come to lie in it.
ducts as small, sac—shaped diverticula; at three and a half months they lie
 
in the genital cord outside the prostate (figs. 1, 2, '3, 4, and 5). It is only
 
with the further development of the latter that they come to lie in it.
 
  
The stroma of the prostate consists of white fibrous tissue and smooth
+
The stroma of the prostate consists of white fibrous tissue and smooth muscle; the latter is disposed in the periphery of the gland, but a few of the fibres penetrate into the core of the gland. These muscle fibres can be readily recognised at three and a half months. The stroma of the prostate is derived from the mesenchyme of the urogenital sinus ; there appears to be no morphological continuity between the stroma of the prostate and the mesenchyme of the genital cord.
muscle; the latter is disposed in the periphery of the gland, but a few of
 
the fibres penetrate into the core of the gland. These muscle fibres can be
 
readily recognised at three and a half months. The stroma of the prostate
 
is derived from the mesenchyme of the urogenital sinus ; there appears to be
 
no morphological continuity between the stroma of the prostate and the
 
mesenchyme of the genital cord.
 
  
The prostatic capsule is derived entirely from the pelvic fascia, with
+
The prostatic capsule is derived entirely from the pelvic fascia, with which it corresponds in structure. At birth this capsule is so sharply marked off from the contained prostate that one could almost imagine the prostateito move freely within it.
which it corresponds in structure. At birth this capsule is so sharply
 
marked off from the contained prostate that one could almost imagine the
 
prostateito move freely within it.
 
  
Lying deep to the anterior segment of the capsule, that is, within the
+
Lying deep to the anterior segment of the capsule, that is, within the capsule, is a lamella of striated muscular tissue, “the musculus prostaticus.” Its fibres pass transversely, and, in adaptation to the anterior surface of the prostate, it is spoon-shaped; laterally, it gains attachment to the deep surface of the capsule and blends with the stroma of the prostate; when traced below, the muscle is seen to be continuous with the compressor urethrae; superiorly, it terminates a little below the neck of the bladder. This muscle is well marked at birth and is always present in the adult. On mesial section it appears biconvex in outline; the thickest part of the muscle (one—quarter inch in the adult) lies below the plane of the utriculus.  
capsule, is a lamella of striated muscular tissue, “the musculus prostaticus.”
 
Its fibres pass transversely, and, in adaptation to the anterior surface of the
 
prostate, it is spoon-shaped; laterally, it gains attachment to the deep
 
surface of the capsule and blends with the stroma of the prostate; when
 
traced below, the muscle is seen to be continuous with the compressor
 
urethrae; superiorly, it terminates a little below the neck of the bladder.
 
This muscle is well marked at birth and is always present in the adult.
 
On mesial section it appears biconvex in outline; the thickest part of the
 
muscle (one—quarter inch in the adult) lies below the plane of the utriculus.
 
A Contribution to the Development of the Prostate in Man
 
  
BIBLIOGRAPHY.
+
==Bibliography==
  
BRYCE, Quaz'n’s Elements of Anatomy, vol. i. “ Embryology,” 1908.
+
BRYCE, Quain’s Elements of Anatomy, vol. i. “ Embryology,” 1908.
  
DIXON, ’l'e:1:t-Book of Anatomy, edited by Cunningham, 1902.
+
DIXON, Text-Book of Anatomy, edited by Cunningham, 1902.
  
 
KEITH, Human Embryology and Morpholngy, 1904.
 
KEITH, Human Embryology and Morpholngy, 1904.
  
GUSTAF PALLIN, Archiv fair Anatomie, 1901, “ Anatomie und Embryologie der
+
GUSTAF PALLIN, Archiv fair Anatomie, 1901, “ Anatomie und Embryologie der Prostata und der Samenblasen.” In the Archiv a very complete literature on the development of the prostate may be found.  
Prostata und der Samenblasen.” In the Archiv a very complete literature on the
 
development of the prostate may be found.
 
  
 
STOHR, Text-Book of Histology, translated by Dr Alfred Schaper, p. 346.
 
STOHR, Text-Book of Histology, translated by Dr Alfred Schaper, p. 346.
  
J. W. THOMSON W'ALKEB, Jour. of Anat. and Phys., vol. xl., April 1906,
+
J. W. THOMSON WALKER, Jour. of Anat. and Phys., vol. xl., April 1906, “On the Surgical Anatomy of the Prostate.”
“On the Surgical Anatomy of the Prostate.”
 
  
 
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Evatt EJ. A contribution to the development of the prostate in man. (1909) Jour. of Anat. and Phys. 43: 314-321.

Online Editor Note 
Mark Hill.jpg
This historic 1909 paper by Evatt is an early description of male prostate development.

See also - Evatt EJ. The development of the prostate gland in the human female, and a study of the homologies of the urethra and vagina of the sexes. (1911) J. Anat. and Physiol. 45: 122-30. PubMed 17232868

Lowsley OS. The development of the human prostate gland with reference to the development of other structures at the neck of the urinary bladder. (1912) Amer. J Anat. 13(3): 299-346.

Spaulding MH. The development of the external genitalia in the human embryo. (1921) Contrib. Embryol., Carnegie Inst. Wash. Publ. 81, 13: 69 – 88.

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1887-88 Testis | 1901 Urinogenital Tract | 1902 The Uro-Genital System | 1904 Ovary and Testis | 1904 Leydig Cells | 1904 Hymen | 1905 Testis vascular | 1909 Prostate | 1912 Prostate | 1912 Urinogenital Organ Development | 1914 External Genitalia | 1914 Female | 1915 Cowper’s and Bartholin’s Glands | 1920 Wolffian tubules | 1921 Urogenital Development | 1921 External Genital | 1927 Female Foetus 15 cm | 1932 Postnatal Ovary | 1935 Prepuce | 1935 Wolffian Duct | 1942 Sex Cords | 1943 Testes Descent | 1953 Germ Cells | Historic Embryology Papers | Historic Disclaimer
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A Contribution to the Development of the Prostate in Man

By Mr Evelyn John Evatt, University College, Cardiff.

  • In connection with this contribution I desire to thank Professor Wiedersheim of the Anatomical Institute, Freiburg in Breisgau, for the generous way in which he placed the facilities of his department at my disposal; and I also wish to acknowledge my indebtedness to Professor Keibel for the very helpful advice I received from him during the construction of a wax-plate model of the glandular tissue of the prostate. The following conclusions regarding the development of the prostate have been arrived at chiefly from a study of this model and of the sections from which the model was built up.


The foetus from which the prostate was taken was said to be three and a half months old. It measured 12 cm. from vertex to coccyx. The foetus was injected through the umbilical vein with a 10 per cent. solution of formalin. The sections, which were 12 micro-millimetres thick, were stained with picrocarmine. The model represents a magnification of 64. When the model was fully constructed it was split down, just a little to the left of the middle line, so as to leave the anterior ducts associated with the right half. The short transverse lines in figs. 2 and 3 indicate the plane along which it was split. In the model the ducts represent the Whole thickness of the epithelial walls of the original ducts. This was done because one could not always recognise the lumen of every duct, and further, because the outline of the epithelial buds was sharply demarcated from the surrounding tissues, and could therefore be accurately traced. In the case of the prostatic urethra the inner wall was traced, so that the model represents, as it were, a cast of the inside of the prostatic urethra with the prostatic ducts in their whole thickness attached to it.


In the course of this paper I shall suppose the foetus to be in the anatomical posture, and employ the terms superior and inferior, anterior and posterior, in the sense in which they are used nowadays.


The prostatic urethra at this stage of development, three and a half months, consists of two parts: (1) an upper fourth, and (2) a lower threefourths (figs. 2 and 3, U.S. and L.S.). Just near the neck of the bladder the urethra has the shape indicated in fig. 5 on transverse section; a little lower down it takes on the form seen in fig. 6. These two outlines represent the form of the upper fourth of the urethra at its upper and lower ends.

Evatt1909 fig01-04.jpg


Different views of the two halves of a wax-plate model of the rostatic urethra and glandular tissue of the prostate. The short transverse lines in figs. 2 and 3 in icate the plane along which the model was split.

Figs. 1 and 2, outer and inner surfaces of the right half respectively. Figs. 3 and 4, inner and outer surfaces of the left half respectively. U.S., up r subdivision ; L.S., lower subdivision: U., urethra; A.D., anterior ducts ; I.lI.D., inferior horizontal ducts; 3r L.D.. ducts of the “3rd lobe ”; W.D., Wolflian ducts; V.S., vesicular seminnles ; M.D., Miillerian ducts.


The lower subdivision of the prostatic urethra is spur-shaped on transverse section (fig. 7); the difference in shape is associated with the presence of the crista urethralis in the lower three-fourths.

The Wolffian and Miillerian ducts (genital cord) enter the lower subdivision at the junction of its upper and middle thirds (figs. 2 and 3, M.D. and W.D.) ‘

The arrangement of the ducts arising from the lower subdivision.

Four ducts grow out from the anterior limb of the urethra; they are all directed upwards, and do not branch (figs 1 and 2, AD.).

Evatt1909 fig05.jpg

FIG. 5. Section through the prostate and genital cord at the upper end of the “ upper subdivision ” of the prostate. Pr., prostate; G.C., genital cord ; U., cavity of the urethra ; A.D., P.D., L.D., anterior posterior, and lateral prostatic ducts respectively; W. D. (V .S.), Wolfilan ducts (vesiculae seminales).


The ducts which come off from the bottom of the prostatic sinus are nine in number on each side; they arise at intervals along its whole length ; they pass backwards for a short distance, and then turn upwards, branching frequently and irregularly. The upper ones are larger and more branched than the lower, being apparently in a more advanced stage of development (figs. 1 and 4:).

Seven ducts pass out from the outer wall of each sinus; the more anterior of these are unbranched (figs. 1 and 4:). They all pass upwards.

Three ducts, the inferior horizontal, arise from the internal wall of each sinus, below the point of entrance of the genital cord; they pass directly backwards, branching frequently (figs. 2 and 3, I.H.D.). They are remarkable in that they are the only ducts which do _ not pass upwards. N o ducts grow out from the summit of the crista urethralis.

Upper subdivision of the prostatic urethra (figs. 2 and 3, U.S.).

Three ducts take origin from the anterior limb or angle (figs. 1 and 2); they are short, and of considerable thickness; they pass upwards and do not branch.

Evatt1909 fig06.jpg


FIG. 6. Transverse section throu h the middle of the “upper subdivision ” of t e prostate. l-7., urethra; A.D., L.D., anterior and lateral prostatlc ducts respectively ; P.D., posterior prostatic ducts (those of the 3rd lobe) ; W.D., Wolfllnn ducts.

Four ducts arise from the outer wall on each side; they lie in series with the lateral ducts of the lower subdivision (figs. 1 and 4).

The two largest ducts of the prostate arise one from each postero— external angle of the urethra (figs. 2 and 3, 3rd L.D.). They first pass downwards for a short distance and then turn upwards, branching frequently and irregularly, their branches nearly touching in the middle line behind. They seem to have been first observed by Henle, though later observers apparently failed to find them. They may be termed the ducts of the third lobe. Two small unbranched ducts arise in series with these, and on a higher plane, and pass upwards: there are thus fifty—nine ducts in all. At first sight it Would seem that the anterior ducts are unpaired, and were not bilaterally symmetrical, but an examination of the transverse sections of the prostate appears to reveal the true history of these ducts; for instance, a transverse section through the middle of the prostate shows two ducts springing from the anterior wall of the urethra (fig. 8, A); higher’ up the appearance is as in fig. 8, B ; fig. 8, C, is still higher; and finally, fig. 8, D, shows only one duct. These sections would seem to show that originally on the right side there were ducts corresponding with those on the left, and that the latter assumed a mesial position owing to the former not going on to further development.

Evatt1909 fig07.jpg

Fig. 7. Transverse section through the “lower subdivision ” of the prostate in the neighbourhood of the Wolffian and Miillerian ducts. W.D., Wolflian ducts; M. D., Miillerlan ducts; U.. urethra; A.D., P.D., anterior and posterior prostntic ducts respectively ; LD. and S.D.. lateral ducts.

The Lobes of the Prostate

At first the prostatic sinuses and their ducts in the lower subdivision are widely separated (figs. 7 and 8). The ducts from the bottom of each sinus, together with those which grow out from the lateral walls of each sinus, may be regarded as forming the lateral lobe of that sinus. The branches of the ducts from the bottom and outer Wall of one sinus probably do not meet those of the other side behind, though the branches of the ducts from the inner walls of the sinus (the inferior horizontal ducts, figs. 2 and 3, I.H.D.) do so.

The branches of the two largest ducts (the ducts of the third lobe, figs. 2 and 3, 3rd L.D.) come together in the middle line behind, and these with the two smaller ducts immediately above them form a centrally placed lobe above the level of the point of entrance of the genital cord. This is the third lobe; it consists of ducts derived from both sides of the prostate, and cannot therefore be regarded as an azygos structure.

Development of the Ducts

Certain of these are formed by a pinching oil" of a portion of the urethral lining membrane in its long axis. This fold or tuck eventually separates from the urethra, except at its lower end, where it remains attached to, and in communication with, the urethra: the process of separation begins at the upper end. Ducts developed in this manner possess a lumen from the outset.


Evatt1909 fig08.jpg

Fig. 8. A, B, C, D, a series of the. transverse sections through the “lower subdivision” of the prostate, passing in that order from below upwards. A.D., anterior ducts; Pr.S., prostatic sinus.


With reference to the development of the prostatic ducts, Pallin observes “so betrachte ich es als im hochsten Grade Wahrscheinlich, obschon nicht ganzlich bewiesen, dass auch diese hinteren und demnach alle menschlichen Prostatadriisen durch Abschniirung \'OIl longitudinalen Falten an der Urethralwand angelegt werden ” (p. 142, Archie fitr Anatomie, 1901).

As regards the ducts which pass up and do not branch, Pallin’s statement of their mode of origin is probably correct. The inferior horizontal ducts (figs. 2 and 3, I.H.D.), which Pallin does not seem to have observed, and the large ducts of the third lobe, cannot have been separated as longitudinal folds.

I have not been able to satisfy myself that any of the prostatic ducts grow out as“ solid buds.” On the contrary, I am inclined to believe that even at the distal end of a given duct the presence of a lumen can be postulated from the radial disposition of the cells lining the duct.

The Miillerian ducts coalesce for a short distance before entering the posterior wall of the urethra upon the summit of the crista, between the Wolflian ducts ; they then extend backwards as a bicornuate structure. The left cornu as compared with the right is enormously developed and flattened from side to side; it extends above and below the right, which is small and flattened from above downwards (fig. 2, M.D.). At three and a half months the Miillerian ducts enter the urethra at right angles to its long axis; at birth it is seen to enter obliquely from above downwards and forwards.

The Wolffian ducts are also seen to enter the urethra at right angles to its long axis and in the same horizontal plane with the Miillerian ducts.

The vesiculae seminales are observed growing out from the Wolflian ducts as small, sac—shaped diverticula; at three and a half months they lie in the genital cord outside the prostate (figs. 1, 2, '3, 4, and 5). It is only with the further development of the latter that they come to lie in it.

The stroma of the prostate consists of white fibrous tissue and smooth muscle; the latter is disposed in the periphery of the gland, but a few of the fibres penetrate into the core of the gland. These muscle fibres can be readily recognised at three and a half months. The stroma of the prostate is derived from the mesenchyme of the urogenital sinus ; there appears to be no morphological continuity between the stroma of the prostate and the mesenchyme of the genital cord.

The prostatic capsule is derived entirely from the pelvic fascia, with which it corresponds in structure. At birth this capsule is so sharply marked off from the contained prostate that one could almost imagine the prostateito move freely within it.

Lying deep to the anterior segment of the capsule, that is, within the capsule, is a lamella of striated muscular tissue, “the musculus prostaticus.” Its fibres pass transversely, and, in adaptation to the anterior surface of the prostate, it is spoon-shaped; laterally, it gains attachment to the deep surface of the capsule and blends with the stroma of the prostate; when traced below, the muscle is seen to be continuous with the compressor urethrae; superiorly, it terminates a little below the neck of the bladder. This muscle is well marked at birth and is always present in the adult. On mesial section it appears biconvex in outline; the thickest part of the muscle (one—quarter inch in the adult) lies below the plane of the utriculus.

Bibliography

BRYCE, Quain’s Elements of Anatomy, vol. i. “ Embryology,” 1908.

DIXON, Text-Book of Anatomy, edited by Cunningham, 1902.

KEITH, Human Embryology and Morpholngy, 1904.

GUSTAF PALLIN, Archiv fair Anatomie, 1901, “ Anatomie und Embryologie der Prostata und der Samenblasen.” In the Archiv a very complete literature on the development of the prostate may be found.

STOHR, Text-Book of Histology, translated by Dr Alfred Schaper, p. 346.

J. W. THOMSON WALKER, Jour. of Anat. and Phys., vol. xl., April 1906, “On the Surgical Anatomy of the Prostate.”


Cite this page: Hill, M.A. (2019, October 23) Embryology Paper - A contribution to the development of the prostate in man. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Paper_-_A_contribution_to_the_development_of_the_prostate_in_man

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