File:Shaw1932 fig01.jpg

Fig. 1. Section through region of primitive streak of specimen No. 1

The decidua (C) is necrotic, the vi ii (B) are simple, showing but a minor degree of branching. The magma reticulare (A) intervenes between embryo and trophoblast. The up r of the two vesicles of the embryo is the amnion ; the lower, the yo k sac. Blood islands (E) can be seen in wail of yolk sac. The primitive streak can be distinguished in the embryonic plate. The entoderm (D) has separated from the mesoderm in the preparation of the specimen.

Fig. 2. Specimen No. 1. High power. Section through the region of primitive streak and groove. A, magma reticulare; B, extra-embryonic mesoderm; 0, cells of amnion; D, amniotic sac ; E, entoderm; F, primitive groove; G, embryonic mesoderm ; H, cavity of yolk sac.

Figs. 3 and 4. A, cerebral vesicle; B, heart; 0, coelom; D, intestine; E, primitive kidney; F, limb bud; G, dorsal aorta; H, neural canal; C, chorionic villi ; K, amnion; L, umbilical vessel ; M, mesone hric duct; N, neural canal of the embryo , 0, liver. The smaller embryo has no head, heart, or liver. The area of fusion is in the region of the primit ve kidney and umbilicus. The amnion is single.

Reference

Shaw W. Observations on two specimens of early human ova. (1932) Brit. Med.J., 1: 411-415.

Cite this page: Hill, M.A. (2024, April 19) Embryology Shaw1932 fig01.jpg. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/File:Shaw1932_fig01.jpg

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