Part 1 of Essay
The Hypothalamus releases the gonadotropin-releasing hormone(GnRH). This hormone actives the pituitary gland to release the follicle-stimulating hormone(FSH) and the luteining hormone(LH). FSH is carried by the blood to the ovaries, where the follicle development is stimulated. The follicles secretes estrogen which initia ....

Part 2 of Essay
.... to expell the endometrium. However, if the egg is fertilized the level of estrogen and progesterone must remain high so the endometrium is not shed. The outer layer of the egg mass(blastocyct) produces a hormone(HCG) to maintain the corpus luteum for the first 3 months of pregnancy so it can provide high levels of estrogen and progesterone. After the third month the placenta provides enough estrogen and progesterone to maintain the endometrium and also to inhibit further ovulation. Conception is when the eg ....