Reproductive System…

1. Reproductive System… Purpose: to produce offspring

2. Parts: • Gonads: • testes/ovaries • produce gametes (sperm/egg)through meiosis • produce sex hormones (testosterone/estrogen/progesterone) • Accessory reproductive organs

3. Sex hormones: • for development/function of reproductive organs • sexual behavior/drives.

4. Male function: • To make/deliver sperm to female

5. Male reproductive system I. Testes (gonads) A. Seminiferous tubules • Make sperm (gametes) B. Interstitial cells • Surround seminiferous tubules • Produce testosterone

6. II. Accessory ducts A. Epididymis- temporary storage for sperm. • gain ability to swim • walls contract to propel sperm to ductus deferens

7. B. Ductus deferens (vas deferens) – runs up and over bladder; enclosed in spermatic cord, empties into ejaculatory duct. • Function: propel sperm into urethra **(vasectomy) C. urethra: urinary/reproductive function

10. III. Accessory glands Make semen: • Combination of sperm and fluid • Fluid • transport medium • nutrients for sperm. • Alkaline (basic)pH (7.2-7.6) neutralizes acid environment (3.5-4) of female vagina (sperm are sluggish in acidic conditions)

11. A. Seminal vesicles(2) – behind bladder; most seminal fluid; joins ductus deferens; provides fructose (ATP production by sperm);

12. B. Prostate– just below bladder 1. produces seminal fluid – contains citric acid (used by sperm for ATP production via Krebs cycle) 2. Hypertrophy strangles urethra

13. C. Bulbourethral gland– 2 functions: cleanse urethra & lubricate

14. IV External genitalia A. Scrotum: 1. Divided sac of skin 2. responds to temperature to produce viable sperm B. Penis: 1. shaft, glans penis (enlarged tip) , prepuce (foreskin – removed during circumcision) 2. Internally: erectile tissue – fills with blood to cause erection.

15. Male infertility: • Semen analysis: sperm count, motility (how well they move), morphology (what they look like), semen volume, pH, fructose content • Normal sperm count= 50-100 million sperm in 2-5 mL of semen • Sperm count of 20 million or less makes impregnation improbable.

16. PICTURES IN TEXT • MALE: • P1058, 1060 (cadaver) • p1059 (cross section – diagram – penis)

17. Female function: • Produces ova (eggs) • provide protective environment for embryo/fetus

18. Female reproductive anatomy I. Ovaries – • produce eggs (gametes) and estrogen and progesterone (hormones)

19. Ovaries • Contains tiny saclike structures -ovarian follicles- which contain an oocyte (immature egg). • When the egg is mature it is ejected from the ovary – ovulation. (approximately every 21-35 days) • Ovaries are held in place by ligaments: suspensory, ovarian and the broad ligament.

22. Fetal pig

24. II. Accessory ducts: A. Uterine tubes (fallopian tubes)- not continuous with ovaries • Receive ovulated egg and transport it to uterus • Provide site of fertilization 3. contain fimbria – fingerlike projections that “catch” ovulated egg.

25. B. Uterus- 1. In pelvis between bladder and rectum 2. Function: receive, retain, nourish fertilized egg 3. 3 parts: body, fundus (top), cervix (narrow opening to vagina)

26. 4. Wall of uterus has 3 layers: endometrium (inner layer) – fertilized egg implants in it or sloughs off during menstruation. myometrium (middle layer) – smooth muscle that contracts during labor epimetrium (outer layer)- prevents friction with surrounding body cavity

27. Cervical cancer – cancer of the uterine cervix Risk group: women between the ages of 30-50 Risk factors: frequent cervical inflammation, sexually transmitted diseases, active sex life with many partners. Screening: yearly pap smear starting age 18 or when 1st sexually active.

28. C. vagina -extends from cervix to body exterior -passageway for the delivery of an infant (birth canal) and for menstrual flow

30. III. External female genitalia: Vulva A. Mons pubis: Fatty, rounded area overlying the pubic symphysis B. Labia: Labia majora (outer skin folds) and labia minora (inner skin folds) C. Vestibule: region that includes the external openings of the urethra (anterior) and vagina (posterior)

31. D. Greater vestibular glands: one on each side of vagina for lubrication during intercourse E. Clitoris: anterior to vestibule, contains sensitive erectile tissue that becomes swollen with blood during sexual excitement

32. Menstrual Cycle: • Days 1-5: thick endometrial lining is detaching. Detached tissues and blood pass through vagina as menstrual flow. • Days 6-14: Rising estrogen levels from growing follicles (in ovaries) stimulate endometrium to become repaired with increased blood supply. Ovulation happens at the end of this stage (due to surge in FSH, LH, and estrogen).

33. Days 15-28: Old ruptured follicle (corpus luteum) produces rising levels of progesterone that increases blood supply of endometrium more. • fertilization occurs: the embryo produces a hormone that causes the corpus luteum to continue producing progesterone. • no fertilization: the corpus luteum degenerates & ovarian hormones in blood drop. Blood vessels of endometrium spasm and kink, depriving the endometrial cells of oxygen and nutrients = cell death …menstruation resumes

35. Secondary sex characteristics MALE: Deepening of voice Increased hair growth (facial, axillary, pubic) Enlargement of skeletal muscles Increased heaviness of skeleton

36. FEMALE: • Enlargement of accessory organs (uterine tubes, uterus, vagina, external genitals) • Breast development • Axillary and pubic hair • Increased deposits of fat • Widening of pelvis • Onset of menstrual cycle

37. Sperm vs. egg SPERM: Tiny Equipped with tails for locomotion Very little nutrient-containing cytoplasm Millions in 1 ejaculation EGG Large Does not move by itself (nonmotile) Abundant nutrient reserves in cytoplasm 1 per month…usually

38. Review question • What are the parts of the duct system in males?

39. IN VITRO FERTILIZATION

40. fertilization • Copulation around ovulation • Sperm attracted to egg by chemicals • Many sperm release enzymes from tip of sperm to get to egg plasma membrane. • 1 sperm enters (not the 1st to arrive) • Cell membrane depolarizes to block polyspermy

43. Fertilized egg = zygote: undergoes rapid mitotic cell division - cleavage • After 2 days: 4 cells • After 3 days 16 cells • Produce morula – solid sphere of cells

44. Blastocyst • ball-like circle of cells • Begins at about the 100 cell stage • Secretes human chorionic gonadotropin (hCG) to prod corpus luteum to continue producing progesterone • Attaches to endometrium – implantation (about day 7)

46. AMNION • Amnion surrounds embryo • Filled with amniotic fluid – filtrate of mother’s blood and baby urine • Shock absorber, fetal temperature homeostasis • (amniocentesis – needle procedure to sample fluid that has baby cells in it)

47. Placenta • Connected to fetus by umbilical cord • Forms a barrier between mother and embryo (blood is not exchanged) • Delivers nutrients and oxygen • “after-birth”

48. Effects of pregnancy on mother • Pregnancy – period from conception until birth (270 days; 40 weeks; 10 lunar months) • Anatomical changes • Enlargements of the uterus • Accentuated lumbar curvature • Relaxation of the pelvic ligaments and pubic symphysis due to production of relaxin

49. Effects of pregnancy on mother continued… • Physiological changes • Gastrointestinal system • Morning sickness is common due to elevated progesterone • Heartburn is common because of organ crowding by the fetus • Constipation is caused by declining motility of the digestive tract

50. Physiological changes • Respiratory System • Nasal mucosa becomes congested and swollen • Respiratory rate increases • Urinary System • Kidneys have additional burden and produce more urine • The uterus compresses the bladder