File:Cullen1916 fig02.jpg

Fig. 2. A More Advanced Stage in the Formation of the Umbilical Region

(Human embryo, 1.7 mm. long. - Mall series, 391.) (This embryo has been very carefully described by Dr. Walter E. Dandy (Amer. Jour. Anat., 1910, x, 85).

Note the advancing approach of the cranial and caudal portions of the yolk-sac and its division into a main cavity and two recesses, the fore-gut and the hind-gut, into the latter of which the allantois now opens. The vitelline arteries and veins are clearly seen on the embryonic side of the yolk-sac. The amnion is now gradually enveloping the embryo. Compare the situation of the coelom in this with that in the subsequent pictures. There is as yet no umbilical cord. For the first stage of its development, See Fig. 3. folding of the exocoe1om. The arrows indicate the direction that it will follow later.

Reference

Cullen TS. Embryology, anatomy, and diseases of the umbilicus together with diseases of the urachus. (1916) W. B. Saunders Company, Philadelphia And London.

Cite this page: Hill, M.A. (2024, May 19) Embryology Cullen1916 fig02.jpg. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/File:Cullen1916_fig02.jpg

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