Paper - Studies of the intestine and peritoneum in the human foetus - part 5

Embryology - 20 Apr 2024        Expand to Translate
Google Translate - select your language from the list shown below (this will open a new external page)
العربية | català | 中文 | 中國傳統的 | français | Deutsche | עִברִית | हिंदी | bahasa Indonesia | italiano | 日本語 | 한국어 | မြန်မာ | Pilipino | Polskie | português | ਪੰਜਾਬੀ ਦੇ | Română | русский | Español | Swahili | Svensk | ไทย | Türkçe | اردو | ייִדיש | Tiếng Việt    These external translations are automated and may not be accurate. (More? About Translations)

Reid DG. Studies of the Intestine and Peritoneum in the Human Foetus: Part V. (1913) J Anat Physiol. 47(3): 268-281. PMID 17232957

Online Editor

This 1913 paper is the fifth 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: Reid DG. Studies of the Intestine and Peritoneum in the Human Foetus: Part I. (1911) J Anat Physiol. 45(2): 73-84. PMID 17232876 Reid DG. Studies of the Intestine and Peritoneum in the Human Foetus: Part II. (1911) 45(4):406-15. PMID 17232897 Reid DG. Studies of the Intestine and Peritoneum in the Human Foetus: Part III. (1912) 46(4):400-415. PMID17232936 Reid DG. Studies of the Intestine and Peritoneum in the Human Foetus: Part IV. (1913) J Anat Physiol. 47(3): 255-267. PMID 17232956 Reid DG. Studies of the Intestine and Peritoneum in the Human Foetus: Part V. (1913) J Anat Physiol. 47(3): 268-281. PMID 17232957 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 GIT Links: Introduction | Medicine Lecture | Science Lecture | endoderm | mouth | oesophagus | stomach | liver | gallbladder | Pancreas | intestine | mesentery | tongue | taste | enteric nervous system | Stage 13 | Stage 22 | gastrointestinal abnormalities | Movies | Postnatal | milk | tooth | salivary gland | BGD Lecture | BGD Practical | GIT Terms | Category:Gastrointestinal Tract GIT Histology Links: Upper GIT | Salivary Gland | Smooth Muscle Histology | Liver | Gallbladder | Pancreas | Colon | Histology Stains | Histology | GIT Development 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

Historic Disclaimer - information about historic embryology pages

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. Part V

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 Foetus. Part V. By Douglas G. Reid, M.B., Ch.B.

Edin., B.A. Trin. Coll. Camb., Demonstrator of Anatomy in the ‘

University of Cambridge.

THE CoNvoLUTIoNs or THE SMALL INTESTINE (MESENTERIC PLICATIONS).

FOR this study two foetuses, 25 and 37 mm. long, and twenty foetuses, ranging from 12 to 22 cm. in vertex-coccygeal length, were specially examined. The small intestine was carefully drawn in sitn. It was then removed piecemeal, being simply steadied with forceps as this was being done. Thus practically no displacements occurred. The mesentery was not cut. A thin rim of intestine was preserved.

In a former paper I have described the line of the root of the mesentery, and have indicated that this presents an upwardly directed portion upon the fourth stage of the duodenum, and a portion whose direction, at one time transverse, becomes more oblique during, or even before, the descent of the caecum, the result of traction upon, the mesentery by the genito- mesenteric fold. Thus the angle between the two parts opens up. A line which passes downwards through the right end of the third portion of the duodenum to the right deep abdominal ring (the line of the unmodified subduodenal portion of the genito-mesenteric fold), and a line which passes through the junction of the third and fourth parts of the duodenum and the left deep abdominal ring, will serve to map the portion of the abdomen, below the duodeno-jejunal flexure, into a central and right and left lateral regions.

The liver rested upon and concealed a portion of the small intestine. On viewing the small bowel from the front, and before any part of the liver had been removed, I noted that the superficial parts of the intestine in the central region sometimes have as a whole a vertical direction (see fig. 1). This was well marked in Nos. XVII., IX., and XX. On examining these foetuses (see figs. 3, 4:, 5) after the small intestine had been removed it is seen that the loops in the central region lie vertically and are simple. This was especially the case in No. XVII.—13 cm. long. Here fifteen simple loops, parts of which are deeply placed, are present. They are all of practically equal size. Their long axes are parallel to one another and at right angles to the line of the root of the mesentery. Studies of the Intestine and Peritoneum in the Human Foetus 269

Two classes of cases may be recognised according to the arrangement of the “superficial” (anterior) parts of the small intestine in the central region as a Whole. The first class is characterised by vertically directed pieces of bowel, and may be termed the primitive. The second is charac-

FIG. 1.—Foetus 19 cm. long. The figures in this figure and in fig. 2 show the parts of small intestine and mesentery which correspond to one another. (In this foetus the left root fossa was relatively a. deep one (4 mm.), and a piece of small intestine could easily be introduced into it.)

terised by loss of parallelism, general irregularity, or preponderance of

horizontal parts, and may be termed the secondary. The foetus 37 mm.

long (see fig. 18, A) may already be put in the secondary class. P0siti0n.——There are no intrapelvic coils. In the 25 mm. embryo the 270 . :_ Mr Douglas G. Reid

4‘

intestinal loop lies in the umbilical cord (coelom). In the 37 mm. foetus the caecum lies in the middle line in the upper part of the umbilical orifice; and in this orifice are also vertically disposed terminal parts of the ileum (parts numbered (11) and (12) in fig. 18, A). These parts are therefore still in a somewhat more anterior plane than the rest of the intestine.

FIG. 2. —-The same foetus as that from which fig. 1 was drawn. The figures in this figure and in fig. 1 indicate the parts of the mesentery and small intestine which correspond.

“Embryos of 40 mm. long either have the intestine in the cord or in the

peritoneal cavity ” (Mall). F0rm.—Two forms, primitive and secondary, of small intestine may be recognised depending on the presence of any small loops upon the

longer loops. No. XVII. (fig. 3) is a primitive form. Studies of the Intestine and Peritoneum in the Hum-an F oetus 271

FIG, 3. —F(etus N0. XVII., 13 cm. long. The 1i11e of the root of the mesentery is indicated by the interrupted line. In this and in the succeeding diagrams the originally left lamina of the mesentery is indicated by the stippling.

Duodenum

Caacum

FIG. 4.—F0etus N0. IX.

VOL. XLVIT. (THIRD SER. VOL. VIII.)—APRIL 1913. 20 272 Mr Douglas G. Reid

N 0 large loops of pelvic colon are present in this specimen. The secondary forms are variable.

Dz"recti0n.—In the left lateral area the loops have a horizontal direction, tending to become vertical in the lower part of this region (see, e.g., fig. 7).

FIG. 6.—Foetus No. II.

Speaking generally, they are placed at right angles to a line drawn parallel to the root of the mesentery upon the fourth portion of the duodenum. The upper horizontal loops are concealed chiefly by the transverse colon and mesocolon and liver and to some extent by the stomach; sometimes, in addition, the lower of these are covered by parts of vertical loops of small Studies of the Intestine and Peritoneum in the Human Foetus 273

FIG. 8.—Foetus No. XVIII. The retro-duodenal fossa is indicated by the non-stippled I area. It lies behind the fourth portion of the duodenum.

intestine. The originally right lamina of the mesentery of the first loop is anterior (see, e.g., figs. 3, 4) in twelve foetuses (60 per cent. of cases).

The course taken by the bowel immediately succeeding the duodeno- jejunal flexure is most variable. Almost any direction may be taken 274« Mr Douglas G. Reid

FIG. 10. —Foetus No. XII. The pelvic colon is indicated by an interrupted line.

except directly upwards or backwards. In many cases, but not all (see fig. 1), the horizontal parts of the loops in the left lateral region could be recognised before the intestines had been removed (i.e. “ superficially ”), and formed quite a characteristic feature of the left lateral region. Studies of the Intestine and Peritoneum in the Human Foetus 275

In the central region the coils of small intestine are usually placed vertically, at right angles to the line of the corresponding portion of the root of the mesentery. The central area may be invaded by loops Whose

FIG. 11.—Foetus No. X.

FIG. 12.—Foetus No. III.

necks are placed either in the left or (as in No. II. see fig. 6) in the right lateral region.

In No. II. there are two large horizontal loops which are directed by the

liver and colon into the central area, the lower encroaching upon the left lateral area. 276 Mr Douglas G. Reid

In the right lateral region the loops are usually vertical and at right angles to the line of the corresponding root of the mesentery. In a foetus 6 cm. long the loops of intestine in the left lateral area also

FIG. 13,-Foetus No. VIII. The thick interrupted line indicates the pelvic colon. The arrows indicate the direction of the movement referred to.

FIG. 14.—Foetus No. VIII. The bend referred to has been undone. The arrows» indicate the direction in which the movement had occurred.

present a horizontal direction, the loops to the right of this being vertically disposed.

In a foetus 37 mm. long these directions have also already been acquired to some extent, although it is the superficial parts of the small intestine in the left lateral area that present the horizontal disposition (see Studies of the Intestine and Peritoneum in the Human Foetus 277

fig. 18, A), and the horizontal direction is not so apparent when the direc-

tion of the intestinal border of the mesentery is studied as a Whole (see fig. 18, B).

FIG. 15.—Foetus No. XV.

FIG. 16.—Foetus No. I.

I shall now describe a special variation in the form of the small intestine. This variation, which is present in Nos. XI., XII, XIV-, and XVIII. (see figs. 7, 8, 9, 10), is associated With the M-Shaped form 278 I Mr Douglas G. Reid

of pelvic colon, or with the compressed omega form. Little or no room exists between the limbs of these forms of pelvic colon. A large loop of small intestine lies in the right part of the abdominal cavity. Upon it are a number of small loops. Its mesentery is moulded over the right loop of the M—shaped pelvic colon in XI. and XVIII., and over the compressed omega in XII. and XIV. Its right limb lies partly in front of the caecum, and is related to the genito-mesenteric fold.

The arrangement of the “superficial” parts of the loops of small intestine in Nos. XII. and XIV. Was characteristic. Immediately over the middle line were vertical folds of intestine, and on either side of these

FIG. 17.—Foetus No. VII.

tiers of horizontally placed folds. The horizontal parts on the left were parts of the horizontal loops of the left lateral area of the abdomen; and those on the right Were smaller loops lying upon the large colic loop of small bowel. In No. X. (see fig. 11), where there is an M—shaped form of pelvic colon, this type of arrangement is not present; but the caecum is placed relatively higher than in the foetuses with this arrangement. If the M—shaped or compressed omega forms of pelvic colon are relatively small, they may then not be associated with any special arrangement of the coils. There is no form especially characteristic of the primitive omega, because of the size of the space between the limbs of this form of colon. The modifications produced here were of the nature of bends. This is Well seen in Nos. III. and VIII. (see figs. 12, 13, 14) in relation to Studies of the Intestine and Peritoneum in the Human Foetus 279

the curved right limb of the omega. Bent loops are also shown in relation to the liver (see, 6.5)., figs. 3, 5, 11)., In VIII. an extensive bending has taken place.

The upper extremity (opposite B in fig. 13) of a loop had apparently

FIG. 18.—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 opposite the lower border of the liver (cf. fig. 1). In B the interrupted line indicates the course of the duodenum. The parts of 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 descending colon are in contact with, and completely concealed in front by, small intestine. But the posterior abdominal wall l1as been straightened by traction exerted upon it through the hook, and they are thus rendered visible.

at one time occupied a position (indicated by A in figs. 13 and 14) in the neighbourhood of the caecum, and has been displaced by the right limb of the pelvic colon. It had moved through half a circle downwards along the right limb of the omega, then upwards (in front of a central loop of small intestine), so that it comes now to lie between the limbs of the 280 Mr Douglas G. Reid

primitive pelvic colon and in front of another loop (see fig. 13). Unusual distension of the small intestine with meconium rounds off the dihedral

angles formed by the plications of the mesentery along the vertices of

which lie blood—vessels (see fig. 15).

Is there evidence of a constant tendency towards the acquisition of an arrangement such as described by Mall ?1 I examined the small intestine of a 25 mm. foetus, and found that the drawing which I had made of the small intestines was exactly similar, except as regards the relative length of some of the loops, to that given by Mall for an embryo 24 mm. long.

The bends and the direction of the intestine, as Well as the foldings of the mesentery, are exactly similar in my foetus to what is figured by Mall (plate ii. fig. 6).

There appears, then, to be primarily no haphazard arrangement. But already in a foetus (obtained from Dr Yolland of Bromley) 37 mm. long I cannot recognise the primitive loops which Mall has described. At first (see fig. 18, A) it seemed that the part numbered (1) was Mall’s second loop. But careful examination showed that it was only a small part of a relatively large loop 2 (see fig. 18, B), and, moreover, its mesentery was turned in the “ wrong ” direction. (The bowel immediately succeeding the duodeno—j ejunal flexure—Which lay in its adult position—went markedly forwards.) Where, then, are the six primitive loops that Mall has described?

The arrangement of the small intestine in a foetus 6 e111. long I found was similar, and as complex as in the older foetuses. It shows no closer resemblance to the arrangement described by Mall than do the majority of the older foetuses.

In the larger foetuses (from 12 to 22 cm. long) which I have examined up to the present, the modifications which have taken place quite obscure in most cases the six loops of small intestine which Mall describes, if they ever existed, although in some cases (see, e.g., fig. 1) an approach towards the arrangement which he figures, a11d which is sometimes found in’ the adult, may be seen.

Zlfec/cel’s D/ivertIiculum.—-This is present in two out of twenty—one foetuses (96 per cent.) specially examined for it; but since January 1907 I have met With it only in three foetuses and in two adults. It is not present in either the 25 or the 37 mm. foetuses.

It projects from the more caudally situated portion of the ileum

1 “Development of the Human Intestine and its Position in the Adult,” by Franklin P. Mall, The J ohns Hopkins Hospital Bulletin, Nos. 90—91, September—October 1898.

2 It will be seen that it is essential to determine the arrangement of the Whole mesentery. To my mind certain of Mall’s figures do not adequately show this. For this reason I cannot accept all that he asserts regarding the arrangement of the small intestine in these

specimens. Studies of the Intestine and Peritoneum in the Human Foetus 281

(opposite + in fig. 3). It is cylindrical in form, with no smaller pouches upon it; and is 6 mm. long in No. XVII. (13 cm. long) and about 10 mm. long in No. XIX. (20 cm. long). Its diameter is equal to that of the bowel into which it opens, but is somewhat constricted at its base in No. XIX.

It arises from the anterior wall of the intestine, and takes a rectilinear course towards the umbilicus in No. XVII. and towards the anterior abdominal wall in No. XIX.

Its extremity is free.

In No. XVII. a branch of the superior mesenteric artery crosses the front of the ileum and lies upon the process along the line of a slight fold of peritoneum. '

While none of my specimens showed any features inconsistent with the generally received theory of its origin from the vitelline duct, there is no satisfactory explanation of the origin of the comparable duodenal pouches, an example of which I have described in the Journal of Anatomy and Physiology, vol. xlii. p. 194.