physiology notes:

1. Path of sperm in male:

Testes (sperm production)→ epididymis→ sperm duct (vas deferens)→seminal vesicles, prostate, bulbourethral gland → urethra.

2. 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.

4. Erection process:
   1. Relaxed penis is flaccid
   2. Excitation: parasympathetic system→ nitric oxide that relaxes smooth muscle; arterioles dilate, blood fills erectile bodies.
5. Ejaculation:
   1. Sympathetic control→accessory glands contraction
   2. Constriction of bladder sphincter (no urine release)
   3. Semen expelled → orgasm
6. Meiosis I
   1. Prophase: synapsis of chromosomes; crossing over
   2. Metaphase: tetrads line up in equator
   3. Anaphase: sister chromatids remain attached with division
   4. Telophase: interkinesis

7. Meiosis II: 4 haploid daughter cells produced with second division.
8. Primary spermatocytes: formed from spermatogonia; become 4 sperm cells
9. 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:

a. facial hair
b. deepening voice
c. facial hair

16. Egg release pathway: ovaries→fallopian tubes→uterus

17. Oogenesis:

Oogonia produced in ovary form into primary oocytes; first meiotic division
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:

a. 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.

22. 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.