Category:Keibel Embryo 1420

Franz Keibel (1861 - 1929)

This Embryology category includes pages and images that relate to the Franz Keibel's Embryo 1420 was 5.3 mm greatest length, 4.6 mm nape length, and with 36 pairs of somites (primitive segments). This would be equivalent to a Carnegie Stage 14 to 15.

Fig. 576. Reconstruction of the lower end of the body of a human embryo of 5.3 mm greatest length 4.6 mm nape length, and with 36 pairs of primitive segments. (Embryo 1420, from the collection of Professor Keibel, Freiburg i. Br.) The primary excretory duct has come to lie between the visceral and the parietal roots of the a. umbilicalis. At the level of its opening into the bladder it bends at a right angle and at the bend it pushes out the ureter bud stages of the development of the ureter. The hemispherical ureteric anlage is not exactly in the middle of the dorsal wall of the primary duct, but inclines more and more towards its medial surface, the degree of inclination varying in different embryos. When the anlage later elongates to form a canal it always lies at the middle of the dorsal surface of primary duct and, later on, even on its lateral surface, yet in an embryo of 7.8 mm. greatest length it still opened distinctly on the medial surface.

Fig. 605. Model of the caudal portion of the body of a human embryo of 5.3 mm greatest (Embryo 1420, from the collection of Professor Keibel, Freiburg i. Br.) Position and course of the primary excretory duct, position of its opening with reference to the cloaca and the cloacal membrane, anlage of the ureteric bud.