HSCI 100 Lecture Notes - Lecture 20: Chorionic Villi, Human Chorionic Gonadotropin, Zona Pellucida

• School: Simon Fraser University
• Department: Health Sciences
• Course: HSCI 100
• Professor: Nienke Van Houten

Document Summary

*throughout all these stages the combination of genetics and environment contribute to health and disease. Cleavage cells undergo mitotic division (2,4,8etc) without the embryo increasing in size. Growth cells undergo mitotic division as well as increase in size. Morphogenesis the embryo begins to take shape as cells migrate. Differentiation when cells take on specific structure and function (the nervous system is the first visible system of the embryo) Step 1: secretions from the female reproductive tract alter the surface of the plasma membrane of the sperm. Step 2: the sperm contacts the corona radiate, & enzymes spill out of the acrosome. Step 3: the enzymes disrupt cellular attachment, allowing passage of the sperm through the corona radiate & then the zona pellucida. Step 4: the sperm contacts the plasma membrane of the secondary oocyte, & their plasma membranes fuse. Step 5: the sperm enters the cytoplasm of the secondary oocyte.