Popeâs Homily at Vespers on Eve of New Year âHoly Mother Church teaches us to end the year and also our days with an examination of conscience â¦ to be grateful and to ask for forgivenessâ December 31, 2014 ZENIT Staff Francis
Progesterone causes the endometrial glands to secrete, preparing the endometrium for blastocyst implantation. If the oocyte is fertilized, the corpus luteum enlarges to form a corpus luteum of pregnancy and increases hormone production. With pregnancy, chorionic gonadotropin, secreted by the trophoblast of the chorion, prevents degeneration of the corpus luteum.
When estrogen peaks it causes an LH surge which leads to ovulation (release of egg from follicle) and causes the corpus luteum to develop. The corpus luteum produces estrogen and progesterone, which promotes growth and maintenance of the uterine lining (endometrium). When the corpus luteum deteriorates, due to a drop in LH, estrogen production decreases. This triggers menstruation.