Reproduction Physiology

1. Reproductive Physiology By: Dr. T. Simbini

14. Spermatogenesis Spermatogonia Primary spermatocyte Secondary spermatocyte Spermatids Spermatozoa Mitosis (46) 1 st meiotic division (23) 2 nd meiotic division (23) Differentiation Stages from spermatogonia to spermatids appear to be androgen independent. The maturation of spermatids to spermatozoa depends on androgens acting on the Sertoli cells in which the developing spermatozoa are embedded. FSH acts on the Sertoli cells to facilitate the last stages of spermatid maturation. Spermatozoa leaving the testicle are not fully mobile. Continue maturation and acquire motility during passage through the epididymis. Motility is further improved by relaxin (prostate?). Capacity of sperm to fertilise is further enhanced in the female genital tract. Capacitation enhances sperm adherence to the ovum.

37. CONTROL OF TESTICULAR FUNCTION HYPOTHALAMUS ANTERIOR PITUITARY GnRH + TESTES SERTOLI CELL LEYDIG CELL TESTOSTERONE INHIBIN SPERMATOGENESIS FSH LH local - - - Rhythmic release of GnRH from the hypothalamus initiated at puberty

40. Vagina Figure 26.16

47. The Ovaries Figure 26.14a

53. Follicular Phase Figure 26.20

58. Gonadotropins, Hormones, and the Ovarian and Uterine Cycles Figure 26.22a, b

65. Gonadotropins, Hormones, and the Ovarian and Uterine Cycles Figure 26.22c ,d

70. CONTROL OF FSH AND LH SECRETION DURING FOLLICULAR PHASE HYPOTHALAMUS ANTERIOR PITUITARY GRH + OVARY LOW LEVELS OF ESTROGEN INHIBIN FSH LH

71. CONTROL OF LH SURGE AT OVULATION HYPOTHALAMUS ANTERIOR PITUITARY GNRH + OVARY HIGH LEVELS OF ESTROGEN OVULATION FSH LH MATURE FOLLICLE

72. FEEDBACK CONTROL DURING LUTEAL PHASE HYPOTHALAMUS ANTERIOR PITUITARY GNRH + OVARY HIGH LEVELS OF PROGESTERONE LH CORPUS LUTEUM MODERATE LEVELS OF ESTROGEN