BIOM20002 Lecture Notes - Lecture 68: Osteoporosis, Follicular Phase, Corpus Albicans
Document Summary
5 month old fetus has all the primary follicles. If fertilisation does not occur after ovulation the corpus luteum will degenerate and stop producing hormones. Follicle: surface epithelium and theca and granulosa cells. Myometrium is muscle responsible for contracting to deliver baby. Ruptured follicle transforms into corpus luteum in preparation for pregnancy. Endometrium secretory: need implantation after fertilisation because endometrium must be able to support pregnancy. Menses: no pregnancy, bleeding from uterus as endometrium is shed. Proliferative phase: new layer of endometrium in preparation of pregnancy. Secretory phase: conversion of endometrium to secretory structure to promote implantation. A small increase in basal body temp occurs just after ovulation. Slight increase in fsh stimulates follicle to grow and mature into secondary and tertiary follicle. Lh stimulates thecal cells to produce androgens, which are converted to estrogen by aromatase in granulosa cells under stimulation by fsh.
