1. NOTES: CH 46 – Animal Reproduction (part 1)

3. MALE REPRODUCTIVE SYSTEM
Functions:
Produce sperm;
Deliver sperm to female repro. tract;
Produce androgens (male sex hormones).

4. MALE REPRODUCTIVE SYSTEM - Anatomy
● TESTES
-develop in abdomen; descend into scrotum before birth;
-made up of tightly coiled tubes (SEMINIFEROUS TUBULES) where sperm are formed;
-scattered between tubules are the LEYDIG CELLS (produce testosterone and other androgens).

5. (Leydig cells)
TESTIS

6. ● SCROTUM:
-a pouch of skin that encloses the testes for protection and temperature regulation

7. MALE REPRODUCTIVE SYSTEM - Anatomy
● EPIDIDYMIS
-6 meters of tubes; sperm cells are here for approx. 20 days;
-location where sperm become motile, gain ability to fertilize.

8. MALE REPRODUCTIVE SYSTEM - Anatomy
● VAS DEFERENS (muscular tube)
● EJACULATORY DUCT
● URETHRA
-tube that drains both repro. & excretory products

9. MALE REPRODUCTIVE SYSTEM - Anatomy
● PENIS
-3 cylinders of erectile tissue (when filled with blood, penis becomes erect);
-head of penis = glans penis; has thinner covering; is covered by foreskin.

11. MALE REPRODUCTIVE SYSTEM
There are 3 sets of accessory glands (add secretions to semen):
1) SEMINAL VESICLES (2):
● produce 60% of semen volume/fluid;
● fluid contains mucus, fructose sugar (energy!), coagulating enzyme, prostaglandins.

12. MALE REPRODUCTIVE SYSTEM
Accessory glands (continued):
2) PROSTATE GLAND:
● secretes thin, milky, slightly alkaline fluid;
● fluid helps to balance the pH environment of the vagina.

13. MALE REPRODUCTIVE SYSTEM
Accessory glands (continued):
3) BULBOUREHTRAL GLANDS (2):
● secrete viscous mucus PRIOR to ejaculation
● fluid neutralizes any acidic urine in the urethra;
● carries some sperm;
● a.k.a. Cowper’s glands.

14. SEMEN
● consists of: sperm cells and secretions from the seminal vesicles, prostate gland, bulbourethral glands
*typical semen production = 2-5 mL;
*semen first coagulates; then thins & sperm begin to swim through the female reproductive tract…

15. FEMALE REPRODUCTIVE SYSTEM
Functions:
Produce egg cells;
Produce female hormones;
Nurture & protect developing fetus.

16. FEMALE REPRODUCTIVE SYSTEM - Anatomy
● OVARIES:
-about size & shape of almonds
-contains many FOLLICLES…

17. The follicles… *surround, nourish, protect egg cells;
*produce estrogens;
*mature and release egg during monthly cycle (1 follicle per month, starting at puberty and ending at menopause)…this is OVULATION;
*each becomes a CORPUS LUTEUM following ovulation;
*disintegrate if egg is not fertilized.

18. FEMALE REPRODUCTIVE SYSTEM - Anatomy
● OVIDUCTS (“FALLOPIAN TUBES”):
-cilia “pull” the egg cell in and convey the egg down the duct;
-fertilization occurs HERE!!!
● UTERUS (“womb”):
-thick, muscular organ; expands du ring pregnancy;
-inner lining = ENDOMETRIUM, which contains many blood vessels

19. FEMALE REPRODUCTIVE SYSTEM - Anatomy
● CERVIX (neck of uterus)
● VAGINA (birth canal)
-thin-walled chamber where sperm are deposited;
-hymen = vascularized membrane which covers vaginal opening from birth until it is ruptured

20. FEMALE REPRODUCTIVE SYSTEM - Anatomy
● BARTHOLIN’S GLANDS
-small glands near vaginal opening;
-secrete mucus during sexual arousal response.
● LABIA MINORA / LABIA MAJORA
-enclose and protect vaginal opening / urethral opening

22. Sexual Response:
Two types of physiological reactions predominate in both sexes during sexual arousal/response:
● Vasocongestion: filling of a tissue with blood
● Myotonia: increased muscle tension

23. GAMETE PRODUCTION: ● Spermatogenesis: production of sperm cells
● Oogenesis: development of ova
-see figures (pg )

26. Differences between spermatogenesis & oogenesis:
● All 4 meiotic products develop into mature sperm
● Sperm cells continue to develop throughout a male’s life
● Stages of meiosis occur continuously, in an uninterrupted sequence

28. Differences between spermatogenesis & oogenesis:
● Uneven cytokinesis; most cytoplasm goes to 2° oocyte (becomes ovum); the other products (polar bodies) disintegrate
● Female is born with all of her egg cells
● Has long “resting” periods of meiosis