Reproductive system Notes


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This slideshow is intended for students in Mr. Hildebrandt's anatomy & physiology classes.

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Reproductive system Notes

  1. 1. Essentials of Human Anatomy & PhysiologyThe Reproductive System Anatomy & Physiology Mr. Hildebrandt
  2. 2. Reproductive System Functions• Ensure the continuation of the human species• Designed to produce, store & transport gametes (sex cells).• Gonads (sex organs) carry out meiosis to produce gametes: • Testis – Male gonads produce sperm • Ovaries – Female gonads that produce eggs
  3. 3. Reproductive System Development• Sexual Dimorphism (differentiation) begins soon after fertilization• Dependant upon the development of endocrine & urinary systems• Puberty marks reproductive maturity• Gamete production slows when there is a reduction in sex hormones: • Males – Andropause • Females - Menopause
  4. 4. Male External Genitalia• Scrotum: divided sac that maintains testes at 3°C lower than normal body temperature to protect sperm viability• Penis: • Shaft: contains three areas of erectile tissue • Glans penis (enlarged tip) • Prepuce (foreskin) • Folded cuff of skin around proximal end • Often removed by circumcision
  5. 5. Male Gamete Production• Spermatogenesis (sperm production) begins in the testis and takes 64-72 days• Each lobule of the testis contains 1-4 seminiferous tubules• Interstitial cells in testis produce androgens such as testosterone
  6. 6. Sperm Cell – The male gamete• The only human flagellated cell• DNA is found in the head• Are produced from puberty until death
  7. 7. Male Reproductive System• Testis – male gonad• Epididymis• Ductus (vas) deferens• Seminal vesicles• Prostate gland• Bulbourethral (Cowper’s) gland• Urethra
  8. 8. Semen – designed to survive the female reproductive tract• Mixture of sperm and accessory gland secretions• Advantages of additive secretions: • Fructose provides energy for sperm cells • Alkalinity of semen helps neutralize the acidic environment of vagina • Semen inhibits bacterial multiplication • Elements of semen enhance sperm motility
  9. 9. Male Reproductive System
  10. 10. Female External Genitalia• Vaginal orifice• Vestibule• Clitoris• Labia majora• Labia minora
  11. 11. Female Gamete Production• Oogenesis (egg production) takes place in the ovaries• The total supply of eggs are present at birth• Ability to release eggs begins at puberty• Reproductive ability ends at menopause• Oocytes (female gamete) are matured in developing ovarian follicles
  12. 12. Ovarian Follicle Stages• Primary follicle – contains an immature oocyte• Graafian (vesicular) follicle – growing follicle with a maturing oocyte• Ovulation – when the egg is mature the follicle ruptures • Occurs about every 28 days • Ruptured follicle transforms into corpus luteum
  13. 13. Female Reproductive System• Ovaries• Fallopian tubes• Uterus• Cervix• Vaginal canal
  14. 14. Female Reproductive System
  15. 15. Menstrual (Uterine) Cycle• Pituitary gland secretes follicle stimulating hormone (FSH) into bloodstream.• Ovaries recognize FSH & produce a follicle (egg & supportive cells).• Follicle secretes estrogen into bloodstream.• Estrogen leads is recognized by: • Pituitary gland which stops secreting FSH • Uterus which begins to thicken its lining• Pituitary gland now secretes lutenizing hormone (LH) into bloodstream.
  16. 16. More of the Menstrual Cycle• The ovary recognizes LH and releases an ovum – ovulation.• Supportive cells left behind in the ovary (now called the corpus luteum) secrete progesterone into the bloodstream.• Progesterone is recognized by: • Pituitary gland which stops secreting LH • Uterus which rapidly thickens its lining• If no fertilization occurs, corpus luteum breaks down & stops making progesterone• Without progesterone, the extra uterine lining is shed - menstruation
  17. 17. Hormonal Control of the Ovarian and UterineCycles
  18. 18. Sexual Reproduction• Requires sexual dimorphism• A certain amount of arousal is necessary• Copulation is the transfer of sperm to the female reproductive tract• Fertilization takes place in the female fallopian tubes• Embryo implants in the female uterus• Embryogenesis is comprised of the 23 Carnegie stages of development
  19. 19. Human Fertilization• The oocyte is viable for 12 to 24 hours after ovulation• Sperm are viable for 12 to 48 hours after ejaculation• Sperm cells must make their way to the uterine tube for fertilization to be possible• The membrane of the oocyte does not permit a second sperm head to enter
  20. 20. Human Fertilization
  21. 21. Childbirth (Partition)• Labor – the series of events that expel the infant from the uterus• Initiation of labor: • Estrogen levels rise • Uterine contractions begin • The placenta releases prostaglandins • Oxytocin is released by the pituitary • These hormones produce contractions
  22. 22. Human Mammary Glands• Modified sweat glands: • Alveolar glands – clusters of milk producing glands within lobules • Lactiferous ducts – connect alveolar glands to nipple• Present in both sexes, but only function in females• Stimulated by sex hormones (mostly estrogens) to increase in size