2. Meiosis  Division of cells (in ovaries and testes) forming haploid gametes Haploid: ½ number of chromosomes ○ Humans: 23 chromos in gametes Gametes: Sex cells (sperm and egg)  Occurs in two divisions (Meiosis I and Meiosis II) which leads to new four cells

4. Testes  Ovoid structures located within the scrotum  Covered in connective tissue Connective tissue also divided internal area into lobules Each lobule has 1-4 seminiferous tubules ○ Function in spermatogenesis  Other cells surrounding tubules are interstitial cells Function in production of male hormones

6. Spermatogenesis  During embryonic development: Spermatogonia in testes go through mitosis and some enlarge to become primary spermatocytes  Starting at puberty: Starting at puberty: Primary spermatocytes go through meiosis becoming secondary spermaocytes (2) and then spermatids (4) Review animation

8. Sperm cells Sperm cells  Acrosome Covering to head of sperm, helps penetrate egg cell  Head Contains the nucleus  Midpiece Many mitochondria to supply energy to support motion  Tail Tail Flagellum that provides movement

10. Epididymis  Tightly coiled tube  Starts on top of the testes and runs along the posterior surface of the testes  Receives immature sperms cells from seminiferous tubules  Matures sperm cells as peristalsis moves them along

11. Vas Deferens  Muscular tube that enters abdominal cavity  Receives sperm from epididymis  Combines with seminal vesicle near prostate gland to become ejaculatory duct

12. Seminal vesicle  Sac-like structure attached to vas deferens near prostate gland  Fluid is alkaline and contains fructose and prostaglandins Alkaline- controls pH Fructose- provides energy for sperm Prostaglandins- stimulates contractions of female reproductive system to move sperm towards egg

13. Prostate Gland  Surrounds urethra just under the urinary bladder  Secretes a thin, milky alkaline fluid Balances pH and enhances motility of sperm

14. Bulbourethral Gland  Within muscle fibers of external urethral sphincter  Secretes a mucous like fluid that lubricates the glans penis

15. Semen  Fluid that leaves the male body  Contains secretions from several gland (as well as the sperm)  One ejaculation: 2-5 ml of fluid 120 million sperm PER ml = 250-500 million sperm per ejaculation

16. Scrotum  Sac enclosing testis  Divided into two chambers by septum  Move towards or away from body depending upon temperature  Optimal temperature is about 36°C

17. Penis  Transfers urine and semen to outside  Body (shaft) Contains 2 corpus cavernosa and 1 corpus spongiosum Where blood accumulates during erection  Glans penis Enlarged, sensitive area at the end of the penis Covered by the prepuce (foreskin) ○ Can be removed by circumcision

18. Erection  Parasympathetic system releases NO (nitric oxide) during sexual stimulation  NO cause arteries in penis to dilate and veins to be compressed (blood collects in penis)  Emission- movement of sperm into urethra  Ejaculation- movement of semen to outside Bulbourethral gland  Prostate gland  Sperm  Seminal vesicle

19. How can you remember???  P- Point= Erection (Parasympathetic)  S- Shoot= Ejaculation (Sympathetic)

21. Hormonal Control  Hypothalamus secrete Gonadotropin- releasing hormone  Pituitary gland releases FSH and ICSH ICSH ○ Stimulates production of testosterone FSH ○ Stimulates seminiferous tubules to respond to testosterone

23. Testosterone  Increases growth of body hair  Enlargement of larynx and thickening of vocal cords  Thickening of skin  Increased muscular growth  Thickening and strengthening of bones

25. Ovaries  Two ovoid structures in the pelvic cavity  Two regions: 1) Medulla- inner area, loose connective tissue, blood vessels, lymphatic vessels, and nerves 2) Cortex- compact tissue with a glandular appearance due to follicles

27. Oogenesis  During embryonic development, several million primordial follicles develop in cortex Each follicle contains a primary oocyte and surrounding follicular cells Primary oocytes begin meiosis Stopped (until puberty – when they complete Meiosis)  Many of the primary oocytes will degenerate and only 400 to 500 will be released during a lifetime

29. Oogenesis (cont)  During each cycle after puberty, primary oocyte finishes Meiosis I dividing into large secondary oocyte and very small first polar body  After fertilization, secondary oocyte will undergo Meiosis II to form the zygote and a second polar body

30. Comparison: Spermatogenesis vs. Oogenesis Comparison: Spermatogenesis vs. Oogenesis MaleFemale Can occur before birth, occurs everyday until death Timing Before birth, egg development continues during puberty, halts during menopause (~50 yo) Testis Location Ovary 4 haploid sperm cells Produced 1 haploid egg cell, 3 polar bodies

31. Spermatogenesis Oogenesis

32. Follicular maturation and Ovulation  Follicular maturation leads to secondary oocyte and organized layers of follicle cells  Follicle cells bath oocyte in follicular fluid and enventually pushes oocyte against the ovary wall to form a blister  Ovulation occurs when the ovary wall ruptures releasing the secondary oocyte

34. Uterine Tubes  Also called fallopian tubes  Tube expands near the ovary in an area called infundibulum with finger-like extensions called fimbriae  Cilia and peristalsis move the oocyte down the tube

35. Uterus  Hollow organ that protects and supports developing embryo  Uterine tube connects at the dome of the uterus  Neck, or cervix, of the uterus opens into the vagina  Three layers: 1) Endometrium- inner mucous layer 2) Myometrium- thick, muscular layer 3) Perimetrium- outer serous layer

37. Vagina  Fibrous, muscular tube connecting uterus to the outside  Hymen Epithelium and connective tissue that partially covers the vaginal opening  Three layers: 1) Mucosal layer- no mucous glands 2) Muscular layer 3) Fibrous layer

38. Vulva  Labia Majora Outer folds protecting openings to urethra and vagina met together anteriorly at the mons pubis  Labia Minora Inner folds with pinkish color met anteriorly to form clitoris hood  Clitoris Small projection rich in nerves  Vestibule Space enclosed by labia minora  Vestibular glands Located on either side of the vagina, secrete mucous

39. Mammary Glands  Adipose and glandular tissue  Responsible for lactation after birth  Milk moves from the alveolar ducts to lactiferous ducts to the nipple which is surrounded by the areola

40. Changes during Sexual Stimulation  Release of NO (nitric oxide)  Release of mucous to lubricate the vestibule and vagina

41. Female Sex Hormones Female Sex Hormones  Hypothalamus releases gonadotropin releasing hormone  Pituitary gland releases FSH and LH FSH: stimulates maturation of the follicle ○ Maturing follicle produces estrogens LH: stimulates ovulation, promotes formation of corpus luteum  Corpus luteum secretes progesterone and estrogen

43. Climacteric  Males: Decrease in testosterone as age  Females: Decrease in estrogen and lack of progesterone Menses cease (menopause)

44. Birth Control  Types: 1) Timing ○ Ex: Withdrawal before ejaculation, abstinence 2) Mechanical ○ Ex: male condom, intrauterine device, female diaphragm 3) Chemical ○ Ex: creams, foam, jellies with spermicidal properties ○ Create unfavorable conditions for sperm to live

45. Birth Control  Types: 4) Hormonal ○ Ex: birth control pill (injection, oral pills, patch) ○ If used correctly, can be 100% effective ○ Cause: nausea, breast tenderness, skin pigmentation 5) Surgical ○ Ex: vasectomy (males) – remove small section of vas deferens; tubal ligation (females) – uterine tubes are cut and ligated

47. Pregnancy  Gestation: 38 weeks  Divided into three trimesters  Changes in circulatory system: Developing fetus is nourished by umbilical cord Two arteries carrying deoxygenated blood, one vein carrying oxygenated blood Some blood goes to liver while the rest bypasses it using the ductus venosus Foramen ovale- opening between the atria that allows decreased blood flow to the lungs during fetal development

49. Disorders and Diseases  PCOS: Polycystic ovarian syndrome Cysts grow on external layers of ovary Prevent ovulation and hormone production  Endometrious Tumors on lining of uterus Can cause infertility  Prostate and Breast Cancer Rapidly dividing cells inside prostate and mammary gland tissue  Pelvic inflammatory disease Usually caused by STD Infection of uterus, fallopian tubes and/or vagina in women Can cause infertility