Female & Male Reproductive Systems

Puberty Females: - pituitary gland secretes FSH (follicle stimulating hormone) and LH (luteinizing hormone) which target the ovaries - LH & FSH stimulate the maturation of ovaries and female sex hormones (estrogen) - Estrogen stimulates changes in Primary and Secondary sexual characteristics (see textbook) Males: - pituitary gland secretes FSH and LH which target the testicles - LH & FSH stimulate the production of spermatozoa and male sex hormones (testosterone) - Testosterone stimulates changes in Primary and Secondary sexual characteristics(see textbook)

Oogenesis Oogensis process of ovum production by meiosis 700 000 cells could become ova at puberty Oocyte surrounded by ovarian follicle Ovarian follicle starts to mature Oocyte undergoes meiosis I produces 2 haploid cells(1 dies) 2. Middle of cycle: ovarian follicle bursts releasing oocyte into fallopian tube(ovulation) 3. Oocyte undergoes meiosis II, 2 haploid cells (1 dies) 4. If ovum not fertilized, then expelled during menstruation If fertilized, then zygote forms, implants in uterus, develop embryo

Ovarian cycle Process whereby a single ovarian follicle matures and changes into a corpus luteum. Days 1-12 1. Pituitary gland- releases more FSH, stimulates growth of ovarian follicle 2. Ovarian follicle develops, secretes more estrogen Day 13-14 3. Estrogens stimulate pituitary gland to increase LH, FSH (surge!)(day 13) 4. Ovulation occurs!(day 14) 5. Ovarian follicle becomes Corpus Luteum that secretes progesterone 6. Progesterone inhibits production of LH,FSH (thickening endometrium) 7. Not fertilized, corpus luteum disintegrates, less progesterone, menstruation 8. If fertilized corpus luteum makes progesterone, until placenta takes over

Menstrual cycle Represents all periodic changes in the uterine endometrium 1. Menstrual phase(days 1-5) – progesterone decreases, bleeding occurs as as endometrium and unfertilized ovum expelled 2. Proliferation phase(days 6-14)- New ovarian follicle produces estrogen, - Endometrium begins to thicken 3. Secretory Phase (days 15-28)- Corpus luteum increases progesterone production, - Endometrium continues to thicken

Fertile Period Fertile period about 4 days- Ovum lives 12-24 hours, sperm lives 24 hour - about 3 days before, 1 after Menopause- women over 40 years, haven’t menstruated for 1 year. - ovarian and menstrual cycles come to end - hot flashes, mood swings, bone loss (may treat with hormone supplements)

Male Reproduction Spermatogenesis: - the process of sperm production by meiosis - spermatogonium (seminiferous tubules) undergo Meiosis I - then undergo Meiosis II to produce 4 haploid sperm - 120 million sperm/day

Erection Erection:- the increase in volume and rigidity of the penis as a result of sexual arousal - corpora cavernosa, spongiosa fill with blood, - swelling of tissues, erection of penis

Ejaculation The expulsion of semen by the penis See assignment Semen accumulates at bulge of urethra near prostate Causes pressure Contractions of penis & muscles around urethra cause semen to project out Releases: 3.5 mL semen, 350 million sperm (see table 5.36, page 150 for semen components)

Andropause Men get older, hormone levels go down, sperm production decreases Physical and psychological changes, doesn’t affect fertility