HELP! Oogenesis?!

sas473 · Dec 7, 2008

Maturation from primitive germ cell to mature gamete is called Oogenesis... primordial germ cells form oogonia. After repeated mitotic divisions, some of these arrest in prophase of meiosis 1 to form primary oocytes. By the 7th month, nearly all oogonia have become atretic, and only primary oocytes remain surrounded by a layer of follicular cells derived from the surface epithelium of the ovary. Together they form the primordial follicle. At puberty, a pool of growing follicles is recruited and maintained from the finite supply of primordial follicles. Everyday 15-20 follicles begin to grow, and as they mature, they pass through 3 stages: 1) primary or preantral 2) secondary or antral (vesicular, Graafian) and 3) preovulatory. The primary oocyte remains in prophase of the first meitoc division until the secondary follicle is mature. At this point, a surge in luteinizing hormone (LH) stimulates preovulatory growth: meiosis 1 is completed and a secondary oocyte and polar body are formed. Then, The secondary oocyte is arrested in metaphase of meosis II approximately 3 hours before ovulation and will not complete this cell division until fertilization.

~Langman's Medical Embryology

Daytonite, BSN, RN · Dec 7, 2008

A concept map.