- Path of sperm in male:
Testes (sperm production)→ epididymis→ sperm duct (vas deferens)→seminal vesicles, prostate, bulbourethral gland → urethra.
- Semen function:
-acid liquid environment for sperm (prostaglandins,
hyaluronidase, prostate-specific antigen or PSA)
-nutrients for sperm (fructose)
3. Accessory glands for semen: seminal vesicles (fructose, prostaglandins); prostate: fibrinolysin, PSA); bulbourethral (Cowper’s gland): lubricates penis; neutralization of urine in urethra.
- Relaxed penis is flaccid
- Excitation: parasympathetic system→ nitric oxide that relaxes smooth muscle; arterioles dilate, blood fills erectile bodies.
- Sympathetic control→accessory glands contraction
- Constriction of bladder sphincter (no urine release)
- Semen expelled → orgasm
- Meiosis I
- Prophase: synapsis of chromosomes; crossing over
- Metaphase: tetrads line up in equator
- Anaphase: sister chromatids remain attached with division
- Telophase: interkinesis
- Meiosis II: 4 haploid daughter cells produced with second division.
- Primary spermatocytes: formed from spermatogonia; become 4 sperm cells
- Spermiogenesis: transformation of spermatid →spermatozoan
-acrosome: forms cap with lysosomes; midpiece; tail with flagellum and mitochondria.
10 Sertoli cells: give nutrients to spermatids; streamline body for swimming.
11. Gonadotropin releasing hormone: hypothalamic factor that prompts release of FSH and LH.
12. FSH: stimulates
spermatogenesis via testosterone receptivity
LH: causes release of testosterone
13. Testosterone inhibits GnRH release; inhibin monitors sperm production; ↑ sperm = > levels of inhibin that depresses sperm production
14. Dihydrotestosterone: a form of testosterone that must be present for some receptor binding sites (prostate gland); other areas of the brain require transformation into estrogen.
15. Male secondary characteristics:
b. deepening voice
c. facial hair
16. Egg release pathway: ovaries→fallopian tubes→uterus
Oogonia produced in ovary form into primary oocytes; first meiotic
Produces secondary oocyte and first polar body; if not fertilized, the secondary Oocyte degenerates. If fertilized by sperm, it continues to divide into ootid and Second polar body, then into ovum which is now called a zygote.
18. Function of polar bodies:
to expel extra chromosomes
b. to allow the oocytes to remain larger for stored food
19. Cell fertilized by sperm: secondary oocyte
20. Ovulation prompted by: rise in estrogen blood levels causes release of additional LH hormone which cause ovulation
21. Menstrual phase: uterus sheds endometrial lining; lasts 3-5 days
Proliferative phase: rebuilding of endometrium; due to
estrogen; progesterone receptors induced to form; ovlulation takes
place; Graafian follicle becomes corpus luteum
Secretory phase: endometrium prepares for implantation; nutrients produced, Cervical plug prevents sperm entry; if no fertilization, progesterone↓ causing increase of lysosome activity→ menstruation again.
Additional role of estrogen: accelerated growth during puberty;
secondary sex characteristics: breasts, fat on hips, widening of pelvis
Progesterone: pregnancy hormone (placental); prepares breasts for lactation
23. Indifferent gonad: primordial germ cells invade gonadal ridge; if XY male is present, invasion of sex cords occur; if XX, outer cortex cells invaded.24. Menopause: ovaries less responsive to Gonadotropins; decrease in oocyte production; ovulation and menses stop generally from age 46 and up.