文档介绍：Chapter 13
The purpose of reproduction is to produce offspring. The physiological processes of reproduction include fertilization, pregnancy and delivery. Reproduction is modulated by the neuroendocrine system of hypothalamus-adenohypophysis-gonadal axis.
The testes must descend out of the abdomen to function properly. Spermatozoa are produced by mitosis, followed by meiosis, and then followed by spermatogenesis. The main hormones of spermatogenesis are LH, testosterone, and FSH, together with several auxillary hormones.
The first half of the ovarian cycle involves follicular development, which is estrogen-dominated and is separated by a short ovulatory phase from the progesterone-dominated second half, or luteal phase, which prepares the uterus for implantation. All of a woman's primary oocytes (2 million) are present at birth; no more are made afterwards. The ovarian cycle consists of one of the several follicles developing into a primary follicle, then Graafian follicle, then a corpus luteum under the influences of FSH and LH. Ovulation is triggered by a powerful surge of gonadotrophins. The ovarian cycle is "shadowed" by the menstrual cycle during which the uterine endometrium is firstly proliferative (due to estrogen) then secretory (due to estrogen and progesterone). Decline in progesterone and estrogen when the corpus luteum degenerates precipitates a menstruatio