BIO380H5 Chapter 1: Chapter 1 - Part #1
Document Summary
Bio 380 human development textbook notes. Gametogenesis consists of four phases in which phase i is identical in both sexes: phase i the migration of the primordial germ cells (pgc) to the gonads. After the 24th of fertilization, the pgc (precursor of gametes) exit endodermal layer of the yolk sac that is filled with alkaline phosphatase and into the hindgut epithelium. From the hindgut, it passes through the dorsal mesentery and into the primordia gonads. Usually when the pgc"s fail to arrive at the gonads, they die, but those that live form teratomas which are growths that contain differentiated tissues such teeth, hair, etc. Teratomas in the sacrococcygeal region are quite common; while some can be removed, others end up killing the child: phase ii the cells undergo mitosis division (different in the sexes) Once the pgc reaches the gonads, it is called spermatogonia in the testis and oogonia in the ovaries.
