The origin and development of the umbilical cord, and its relation to the amnion / by James Foulis, M.D.

  • Foulis, James.
Date:
[1900]
Catalogue details

Licence: In copyright

Credit: The origin and development of the umbilical cord, and its relation to the amnion / by James Foulis, M.D. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

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    by the splitting of the lateral mesoblast into two layers, one of which joins with the epiblast to form the somatopleure, Som, while the other joins the hypoblast to form the splanch- nopleure Spl, which encloses the intestinal tube In, and which Fig. 3- Am = Amnion. Coe = CcElom. Cho = Chorion. In = Intestine. Fig. 4. Som = Somatopleure. Spl = Splanchnopleure. Yolk = Yolk sac. is Still in communication with the yolk sac by the vitelline foramen. In this figure the lateral somatopleure folds are seen rising up and closing over the dorsum of the embryo ; and in Fig. 4 they are represented as having come together in the middle line ; and as the line of junction gradually absorbs, the true and false amnion are thus formed. The true amnion, Am, im- mediately surrounds the embryo. Its cavity is lined by the epiblast. The outer or false amnion, or chorion, is hned by the mesoblast layer, while the epiblast is on the outside. In both figures the dotted lines represent the mesoblastic layers which are always opposed to each other in the encasing mem- branes. The mesoblast of the one is separated from that of the other by a space occupied by fluid and continuous with the coelom, with which, in fact, it remains continuous until the body- walls of the embryo have entirely grown round and coalesced on the ventral surface, the final point of coalescence being the umbilicus. , In the latter stages of gestation the space between the