Theoogoniahave already matured before birth and women are born with a limited number of primary oocyteswhich have already begun, and are suspended in, prophase of the first meiotic division. Each montha small number of these primary oocytes continue meiosis I, usually fromalternating ovaries, and usually only one becomes a secondary oocyte. (Fertility drugs are FSH derivatives and stimulate many follicles, which increases the probability that some will develop into secondary oocytes to be fertilized) It is the secondary oocyte which is ovulated. Surrounding each early primary oocyte is a primordial follicle. These follicles develop along with the oocytes, first becoming primary folliclesand continuing as growing or secondary follicles, and ultimately becoming a mature (a.k.a. Graafian or vesicular) folliclewhich contains the secondary oocyte which is ovulated.


Post a Comment