Human Reproduction Chapter 15 pp 485 Image credit: Dennis KunkelDennis Kunkel

Male Anatomy Diagram 487 ***** sex organs - testes

Testes suspended in an external sac - scrotum develop in the abdominal cavity and normally descend before birth temp 1.5 degrees lower

Sex cells - sperm –swim by flagella –develop in seminiferous tubules –stored in the epidiymis

Sperm con’t –fluids produced by seminal vessicles, prostate gland and Cowper’s gland –sperms + fluids = semen –travel from the epididymis to urethra by vas deferens

Female Anatomy Diagram - page 490 ***** Sex organs - ovaries

Ovaries In abdominal cavity groups of cells called follicles surround the egg and cause them to mature eggs travel from the ovary to the uterus through the oviducts (fallopian tubes)

Uterus the uterus is a thick-walled muscular organ in which the embryo develops (womb) the lining of the uterus is the endometrium the small opening at the lower end of the uterus is the cervix the cervix open to the vagina (birth canal) –note: the vagina is separate from the urethra which excretes urine.

Fertilization: the union of a monoploid (haploid) egg and sperm forming a diploid zygote. Ovum can only be fertilized for about hours after release sperm can survive for 3-5 days in a woman’s reproductive tract

Sequence of events in fertilization: Millions of sperm ejaculated into the vagina –as ovulation approaches cervical mucus becomes watery allowing sperm to swim through If egg is fertilized, the implanted embryo produces Human Chorionic Gonadotrophin (HCG)

Sequence of events con’t HCG keeps the corpus luteum viable and allows continued production of progesterone. –Progesterone production continues during pregnancy. 1st by CL, then by placenta. –Progesterone inhibits FSH