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Reproduction www.freelivedoctor.com
Reproduction <ul><li>Reproductive System </li></ul><ul><ul><li>Not needed for the survival of the individual </li></ul></u...
Sexual Reproduction <ul><li>Each individual produces gametes </li></ul><ul><ul><li>Formed in gonads by meiosis </li></ul><...
Sexual Determination <ul><li>Each zygote inherits </li></ul><ul><ul><li>23 chromosomes from mother </li></ul></ul><ul><ul>...
Formation of Testes <ul><li>First 40 days after conception the gonads of males and females are similar in appearance. </li...
Formation of Testes <ul><li>Structures in the testes: </li></ul><ul><ul><li>Seminiferous tubules:  43 to 50 days post conc...
Formation of Testes <ul><li>Leydig cells secrete testosterone. </li></ul><ul><ul><li>Begins 8 th  week and peaks at 12-14 ...
Formation of Ovaries <ul><li>Absence of Y chromosome and TDF, female develop ovaries. </li></ul><ul><li>Ovarian follicles ...
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Development of Accessory Sex Organs and Genitalia <ul><li>Presence or absence of testes determines the accessory sex organ...
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Development of Accessory Sex Organs and Genitalia <ul><li>Both duct systems in both sexes  between days 25 and 50 </li></u...
Development of Accessory Sex Organs and Genitalia www.freelivedoctor.com
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Endocrine Regulation of Reproduction <ul><li>First trimester </li></ul><ul><ul><li>Embryonic testes are active endocrine g...
Endocrine Regulation of Reproduction <ul><li>Hypothalamus releases LHRH (GnRH) into hypothalamo-hypophyseal portal vessels...
Endocrine Interactions <ul><li>Primary effects of LH and FSH on gonads: </li></ul><ul><ul><li>Stimulation of spermatogenes...
Endocrine Regulation <ul><li>Negative Feedback: </li></ul><ul><ul><li>Inhibit GnRH from hypothalamus. </li></ul></ul><ul><...
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Onset of Puberty <ul><li>FSH and LH high in newborn, falls to low levels in few weeks. </li></ul><ul><li>Puberty: driven b...
Onset of Puberty <ul><li>FSH and LH </li></ul><ul><ul><li>Brain maturation increases GnRH secretion. </li></ul></ul><ul><u...
Onset of Puberty <ul><li>Stimulate rise in testosterone and estradiol-17  . </li></ul><ul><ul><li>Produce secondary sexua...
Pineal Gland <ul><li>Secretes melatonin. </li></ul><ul><li>Secretion influenced by light-dark cycles. </li></ul><ul><li>In...
4 Phases of Human Sexual Response <ul><li>Excitation phase (arousal): </li></ul><ul><ul><li>Myotonia and vasocongestion.  ...
Male Reproduction System <ul><li>Testes: </li></ul><ul><ul><li>Seminiferous tubules: </li></ul></ul><ul><ul><ul><li>Where ...
Control of LH and FSH Secretion <ul><li>Negative feedback: </li></ul><ul><ul><li>Testosterone inhibits LH and GnRH product...
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Testosterone Secretion <ul><li>Responsible for initiation and maintenance of body changes in puberty. </li></ul><ul><li>St...
Testosterone Secretion <ul><li>Negative feedback of testosterone and inhibin </li></ul><ul><ul><li>Keep relatively constan...
Endocrine function: testes <ul><li>Testosterone: main androgen </li></ul><ul><li>Sertoli and Leydig cells secrete small am...
Spermatogenesis <ul><li>Spermatogonia: </li></ul><ul><ul><li>Replicate initially by mitosis. </li></ul></ul><ul><ul><li>Pr...
Spermiogenesis <ul><li>Maturation of spermatozoa.  </li></ul><ul><li>Cytoplasm is pinched off and ingested by the Sertoli ...
Sertoli Cells <ul><li>Blood-testes barrier: </li></ul><ul><ul><li>Prevents autoimmune destruction of sperm. </li></ul></ul...
Hormonal Control of Spermatogenesis <ul><li>Testosterone required for completion of meiosis and spermatid maturation. </li...
Male Accessory Organs <ul><li>Epididymis:  </li></ul><ul><ul><li>Maturational changes.  </li></ul></ul><ul><ul><li>Resista...
Erection, Emission, and Ejaculation <ul><li>Erection: </li></ul><ul><ul><li>Increased vasodilation of arterioles. </li></u...
Female Reproductive System <ul><li>Ovaries: </li></ul><ul><ul><li>Contain large number of follicles which enclose ova. </l...
Female Reproductive System <ul><li>Fallopian (uterine) tubes: </li></ul><ul><ul><li>Ova drawn into the tube by cilia. </li...
Ovarian Cycle <ul><li>5 mo. gestation  ovaries contain 6-7 million oogonia. </li></ul><ul><li>Oogenesis arrested in propha...
Ovarian Cycle <ul><li>Primary oocytes contained in primary follicles. </li></ul><ul><ul><li>FSH stimulates cell growth. </...
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Ovarian Cycle <ul><li>Secondary oocyte: </li></ul><ul><li>Under FSH stimulation: </li></ul><ul><ul><li>Theca cells secrete...
Ovulation  <ul><li>Graafian follicle forms bulge on surface of ovary. </li></ul><ul><li>Extrudes secondary oocyte into the...
Menstrual Cycle <ul><li>3 phases: Ovarian </li></ul><ul><ul><li>Follicular Phase </li></ul></ul><ul><ul><li>Ovulation </li...
Follicular Phase <ul><li>FSH: </li></ul><ul><li>Stimulates production of FSH receptors on granulosa cells. </li></ul><ul><...
Follicular Phase <ul><li>Rapid rise in estradiol: </li></ul><ul><ul><li>Negative feedback on LH and FSH. </li></ul></ul><u...
Follicular Phase <ul><li>Positive feedback: </li></ul><ul><ul><li>LH surge begins 24 hours before ovulation. </li></ul></u...
Ovulation <ul><li>Under FSH, graafian follicle grows large and thin-walled. </li></ul><ul><ul><li>Triggers LH surge. </li>...
Luteal Phase <ul><li>LH stimulates formation of the empty follicle into corpus luteum. </li></ul><ul><li>Corpus luteum sec...
Luteal Phase <ul><li>Corpus luteum regresses unless fertilization occurs:  </li></ul><ul><ul><li>Estradiol decreases. </li...
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Endometrial Changes <ul><li>3 phases of endometrium changes: </li></ul><ul><ul><li>Proliferative phase. </li></ul></ul><ul...
Proliferative Phase <ul><li>Ovary is in follicular phase. </li></ul><ul><li>Estradiol stimulate growth of endometrium. </l...
Secretory Phase <ul><li>Ovary is in luteal phase. </li></ul><ul><li>Progesterone stimulates development of uterine glands,...
Menstrual Phase <ul><li>Progesterone cause constriction of spiral arteries. </li></ul><ul><li>Necrosis and sloughing of en...
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Menopause <ul><li>Cessation of ovarian activity.  </li></ul><ul><li>Age ~ 50 years. </li></ul><ul><li>Ovaries depleted of ...
Fertilization <ul><li>Ejaculation 300 million sperm, 100 reach (uterine) fallopian tube. </li></ul><ul><li>Fertilization o...
Fertilization <ul><li>As fertilization occurs, secondary oocyte completes 2 nd  meiotic division. </li></ul><ul><li>Sperm ...
Blastocyct Formation <ul><li>Cleavage: </li></ul><ul><ul><li>30-36 hrs. after fertilization the zygote divides by mitosis....
Implantation <ul><li>6 th  day after fertilization, blastocyst attaches to uterine wall. </li></ul><ul><li>Blastocyst secr...
hCG <ul><li>Human chorionic gonadotropin. </li></ul><ul><li>Trophoblast cells secrete hCG. </li></ul><ul><li>Signals corpu...
Placenta <ul><li>Syncytiotrophoblast secretes enzymes that create blood filled cavities in the maternal tissue. </li></ul>...
Placental Changes <ul><li>Decidual reaction: </li></ul><ul><ul><li>Endometrial growth. </li></ul></ul><ul><ul><li>Accumula...
Amnion <ul><li>Envelop the embryo. </li></ul><ul><li>Amnionic fluid contains sloughed cells of the fetus. </li></ul>www.fr...
Placenta Function <ul><li>Gas exchange: </li></ul><ul><ul><li>0 2  and C0 2 . </li></ul></ul><ul><li>Nutrient exchange. </...
Placental Hormones <ul><li>hCS: </li></ul><ul><li>Chorionic somatomammotropin. </li></ul><ul><li>GH effects. </li></ul><ul...
Placental Hormones <ul><li>Fetal-placental unit: </li></ul><ul><ul><li>Placenta must cooperate with the adrenal cortex in ...
Placental Hormones <ul><li>Progesterone: </li></ul><ul><ul><li>Suppresses uterine contractions. </li></ul></ul><ul><ul><li...
Parturition <ul><li>Estrogen in late pregnancy: </li></ul><ul><ul><li>Increases amount of oxytocin stored. </li></ul></ul>...
Lactation <ul><li>Hypothalamus releases PRH. </li></ul><ul><li>Anterior pituitary releases prolactin: </li></ul><ul><ul><l...
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Formation&Development Of Reproductive System

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Transcript of "Formation&Development Of Reproductive System"

  1. 1. Reproduction www.freelivedoctor.com
  2. 2. Reproduction <ul><li>Reproductive System </li></ul><ul><ul><li>Not needed for the survival of the individual </li></ul></ul><ul><ul><li>Species survival </li></ul></ul><ul><li>Sexual reproduction </li></ul><ul><ul><li>Genes from two individual </li></ul></ul><ul><ul><li>Combine at random </li></ul></ul><ul><ul><li>Creates new combinations </li></ul></ul><ul><ul><li>Increases chances of species survival </li></ul></ul>www.freelivedoctor.com
  3. 3. Sexual Reproduction <ul><li>Each individual produces gametes </li></ul><ul><ul><li>Formed in gonads by meiosis </li></ul></ul><ul><ul><ul><li>Male: testes produce: </li></ul></ul></ul><ul><ul><ul><ul><li>Sperm </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Testosterone </li></ul></ul></ul></ul><ul><ul><ul><li>Female: ovaries produce: </li></ul></ul></ul><ul><ul><ul><ul><li>Ova </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Estrogens, Progesterone </li></ul></ul></ul></ul><ul><li>Gametes unite in process of fertilization </li></ul><ul><ul><li>Restores diploid number </li></ul></ul><ul><ul><li>Forms zygote </li></ul></ul>www.freelivedoctor.com
  4. 4. Sexual Determination <ul><li>Each zygote inherits </li></ul><ul><ul><li>23 chromosomes from mother </li></ul></ul><ul><ul><li>23 chromosomes from father. </li></ul></ul><ul><ul><li>23 pairs of homologous chromosomes. </li></ul></ul><ul><ul><ul><li>alleles </li></ul></ul></ul><ul><li>Kinds of chromosomes </li></ul><ul><ul><li>1-22 pairs of chromosomes: autosomal </li></ul></ul><ul><ul><li>23 rd pair are sex chromosomes. </li></ul></ul><ul><ul><ul><li>Male: XY </li></ul></ul></ul><ul><ul><ul><li>Female: XX </li></ul></ul></ul><ul><li>Chromosomal gender of zygote determined by fertilizing sperm. </li></ul>www.freelivedoctor.com
  5. 5. Formation of Testes <ul><li>First 40 days after conception the gonads of males and females are similar in appearance. </li></ul><ul><li>During this time: </li></ul><ul><ul><li>Spermatogonia and oogonia migrate from yolk sac to developing embryonic gonads </li></ul></ul><ul><ul><li>Gonads could become either. </li></ul></ul><ul><li>TDF (testis-determining factor): </li></ul><ul><ul><li>hypothetical </li></ul></ul><ul><ul><li>promotes the conversion to testes: </li></ul></ul><ul><ul><ul><li>gene located on short arm of Y, called SRY (sex determining region of Y chromosome) </li></ul></ul></ul><ul><ul><ul><li>Found in all mammals </li></ul></ul></ul>www.freelivedoctor.com
  6. 6. Formation of Testes <ul><li>Structures in the testes: </li></ul><ul><ul><li>Seminiferous tubules: 43 to 50 days post conception </li></ul></ul><ul><ul><ul><li>Germinal cells: sperm. </li></ul></ul></ul><ul><ul><ul><li>Nongerminal cells: Sertoli cells (sustentacular cells). </li></ul></ul></ul><ul><ul><li>Leydig cells (interstitial cells): </li></ul></ul><ul><ul><ul><li>Appear about day 65. </li></ul></ul></ul><ul><ul><ul><li>Endocrine function: secrete androgens </li></ul></ul></ul><ul><ul><ul><ul><li>Main: Testosterone </li></ul></ul></ul></ul>www.freelivedoctor.com
  7. 7. Formation of Testes <ul><li>Leydig cells secrete testosterone. </li></ul><ul><ul><li>Begins 8 th week and peaks at 12-14 th week. </li></ul></ul><ul><ul><li>Masculinizes embryonic structures. </li></ul></ul><ul><li>Testosterone then declines to very low levels until puberty. </li></ul><ul><ul><li>Decline occurs by end of second trimester </li></ul></ul><ul><li>Testes descend into scrotum shortly before birth. </li></ul><ul><ul><li>Temp about 3 degrees below internal temp </li></ul></ul><ul><ul><li>35 degrees C </li></ul></ul>www.freelivedoctor.com
  8. 8. Formation of Ovaries <ul><li>Absence of Y chromosome and TDF, female develop ovaries. </li></ul><ul><li>Ovarian follicles do not appear until 2 nd trimester. </li></ul>www.freelivedoctor.com
  9. 9. www.freelivedoctor.com
  10. 10. Development of Accessory Sex Organs and Genitalia <ul><li>Presence or absence of testes determines the accessory sex organs and external genitalia. </li></ul><ul><li>Male accessory organs derived from wolffian ducts.( mesonephric ) </li></ul><ul><li>Sertoli cells secrete MIF(mullerian inhibition factor). </li></ul><ul><li>Female accessory organs derived from mullerian ducts. ( paramesonephritic ) </li></ul>www.freelivedoctor.com
  11. 11. www.freelivedoctor.com
  12. 12. Development of Accessory Sex Organs and Genitalia <ul><li>Both duct systems in both sexes between days 25 and 50 </li></ul><ul><ul><li>Regression of mullarian ducts begins about day 60 </li></ul></ul><ul><li>Testosterone </li></ul><ul><ul><li>responsible for development of male accessory sex organs </li></ul></ul><ul><ul><li>External genitalia identical first 6 weeks, then testosterone stimulates development of penis </li></ul></ul><ul><ul><li>Not the active agent in all cells </li></ul></ul><ul><ul><ul><li>converted to dihydrotestosterone (DHT) in some target cells </li></ul></ul></ul><ul><ul><ul><li>Needed for penis, spongy urethra, scrotum, prostrate </li></ul></ul></ul><ul><ul><li>Testosterone directly needed for wolfian derivatives: </li></ul></ul><ul><ul><ul><li>Epididymis, ductus deferens, ejaculatory duct, SV </li></ul></ul></ul>www.freelivedoctor.com
  13. 13. Development of Accessory Sex Organs and Genitalia www.freelivedoctor.com
  14. 14. www.freelivedoctor.com
  15. 15. Endocrine Regulation of Reproduction <ul><li>First trimester </li></ul><ul><ul><li>Embryonic testes are active endocrine glands </li></ul></ul><ul><ul><ul><li>Secrete large amounts of testosterone </li></ul></ul></ul><ul><ul><li>Embryonic ovaries not mature until third trimester </li></ul></ul><ul><li>Time of birth: </li></ul><ul><ul><li>Gonads in both sexes relatively inactive </li></ul></ul><ul><li>Before puberty: </li></ul><ul><ul><li>Low levels of sex steroids in both </li></ul></ul><ul><ul><li>Due to lack of stimulation </li></ul></ul><ul><li>Puberty: </li></ul><ul><ul><li>Increased stimulation from gonadotropic hormones </li></ul></ul><ul><ul><li>Induce increase in sex steroids </li></ul></ul>www.freelivedoctor.com
  16. 16. Endocrine Regulation of Reproduction <ul><li>Hypothalamus releases LHRH (GnRH) into hypothalamo-hypophyseal portal vessels. </li></ul><ul><li>Anterior pituitary secretes: </li></ul><ul><ul><li>LH: luteinizing hormone. </li></ul></ul><ul><ul><ul><li>In male: interstitial-cell stimulating hormone (ICSH) </li></ul></ul></ul><ul><ul><li>FSH: follicle-stimulating hormone. </li></ul></ul><ul><li>Secreted in pulsatile fashion to prevent desensitization and down regulation of receptors. </li></ul>www.freelivedoctor.com
  17. 17. Endocrine Interactions <ul><li>Primary effects of LH and FSH on gonads: </li></ul><ul><ul><li>Stimulation of spermatogenesis and oogenesis. </li></ul></ul><ul><ul><li>Stimulation of gonadal hormone secretion. </li></ul></ul><ul><ul><li>Maintenance of gonadal structure. </li></ul></ul>www.freelivedoctor.com
  18. 18. Endocrine Regulation <ul><li>Negative Feedback: </li></ul><ul><ul><li>Inhibit GnRH from hypothalamus. </li></ul></ul><ul><ul><li>Inhibit anterior pituitary response to GnRH. </li></ul></ul><ul><ul><li>Inhibin secretion inhibit anterior pituitary release of FSH. </li></ul></ul><ul><ul><ul><li>By sertoli cells </li></ul></ul></ul><ul><li>Female: estrogen and progesterone. </li></ul><ul><li>Male: testosterone. </li></ul>www.freelivedoctor.com
  19. 19. www.freelivedoctor.com
  20. 20. Onset of Puberty <ul><li>FSH and LH high in newborn, falls to low levels in few weeks. </li></ul><ul><li>Puberty: driven by increased secretion of FSH and LH </li></ul>www.freelivedoctor.com
  21. 21. Onset of Puberty <ul><li>FSH and LH </li></ul><ul><ul><li>Brain maturation increases GnRH secretion. </li></ul></ul><ul><ul><li>Decreased sensitivity of GnRH to negative feedback. </li></ul></ul><ul><li>LH: </li></ul><ul><ul><li>Increased secretion triggers puberty </li></ul></ul><ul><ul><li>Late puberty, pulsatile secretion of LH and FSH increase during sleep. </li></ul></ul><ul><li>Stimulate a rise in sex steroid secretion. </li></ul>www.freelivedoctor.com
  22. 22. Onset of Puberty <ul><li>Stimulate rise in testosterone and estradiol-17  . </li></ul><ul><ul><li>Produce secondary sexual characteristics. </li></ul></ul><ul><li>Age of onset related to the amount of body fat and physical activity in the female </li></ul><ul><li>Leptin secretion from adipocytes may be required for puberty. </li></ul>www.freelivedoctor.com
  23. 23. Pineal Gland <ul><li>Secretes melatonin. </li></ul><ul><li>Secretion influenced by light-dark cycles. </li></ul><ul><li>Inhibit gonadotropin secretion. </li></ul><ul><li>Role in humans not established. </li></ul>www.freelivedoctor.com
  24. 24. 4 Phases of Human Sexual Response <ul><li>Excitation phase (arousal): </li></ul><ul><ul><li>Myotonia and vasocongestion. </li></ul></ul><ul><ul><li>Engorgement of a sexual organ with blood. </li></ul></ul><ul><ul><li>Erection of the nipples. </li></ul></ul><ul><li>Plateau phase: </li></ul><ul><ul><li>Clitoris becomes partially hidden. </li></ul></ul><ul><ul><li>Erected nipples become partially hidden by swelling of areolae. </li></ul></ul><ul><li>Orgasm: </li></ul><ul><ul><li>Uterus and orgasmic platform of vagina contract. </li></ul></ul><ul><ul><li>Contractions accompanying ejaculation. </li></ul></ul><ul><li>Resolution phase: </li></ul><ul><ul><li>Body return to preexcitation conditions. </li></ul></ul><ul><li>Refractory period </li></ul><ul><ul><li>In males </li></ul></ul><ul><ul><li>Erection possible, but not ejaculation </li></ul></ul>www.freelivedoctor.com
  25. 25. Male Reproduction System <ul><li>Testes: </li></ul><ul><ul><li>Seminiferous tubules: </li></ul></ul><ul><ul><ul><li>Where spermatogenesis occurs. </li></ul></ul></ul><ul><ul><ul><li>Contain receptor proteins for FSH in Sertoli cells. </li></ul></ul></ul><ul><ul><li>Leydig cells: </li></ul></ul><ul><ul><ul><li>Secrete testosterone. </li></ul></ul></ul><ul><ul><ul><li>Contain receptor proteins for LH. </li></ul></ul></ul>www.freelivedoctor.com
  26. 26. Control of LH and FSH Secretion <ul><li>Negative feedback: </li></ul><ul><ul><li>Testosterone inhibits LH and GnRH production. </li></ul></ul><ul><ul><li>Inhibin inhibits FSH secretion. </li></ul></ul><ul><ul><li>Aromatization reaction producing estadiol in the brain is required for the negative feedback effects of testosterone on LH. </li></ul></ul><ul><ul><li>Brain is a target organ for testosterone </li></ul></ul><ul><ul><ul><li>Converted to derivatives </li></ul></ul></ul>www.freelivedoctor.com
  27. 27. www.freelivedoctor.com
  28. 28. Testosterone Secretion <ul><li>Responsible for initiation and maintenance of body changes in puberty. </li></ul><ul><li>Stimulate growth of muscles, larynx, and bone growth until sealing of the epiphyseal discs. </li></ul><ul><li>Promote hemoglobin synthesis. </li></ul><ul><li>Acts in paracrine fashion and is responsible for spermatogenesis. </li></ul>www.freelivedoctor.com
  29. 29. Testosterone Secretion <ul><li>Negative feedback of testosterone and inhibin </li></ul><ul><ul><li>Keep relatively constant levels of gonadotropins </li></ul></ul><ul><ul><li>Results in relatively constant levels </li></ul></ul><ul><ul><li>Different in female </li></ul></ul><ul><ul><ul><li>At menopause: no more sex steroids </li></ul></ul></ul><ul><ul><li>In males, gradual decrease </li></ul></ul>www.freelivedoctor.com
  30. 30. Endocrine function: testes <ul><li>Testosterone: main androgen </li></ul><ul><li>Sertoli and Leydig cells secrete small amounts of estradiol. </li></ul><ul><ul><li>Have receptors for estradiol (as do other male structures) </li></ul></ul><ul><ul><li>May be needed for spermatogenesis </li></ul></ul><ul><li>Estradiol may be responsible for: </li></ul><ul><ul><li>Negative feedback in brain. </li></ul></ul><ul><ul><li>Sealing of epiphyseal plates. </li></ul></ul><ul><ul><li>Regulatory function in fertility. </li></ul></ul>www.freelivedoctor.com
  31. 31. Spermatogenesis <ul><li>Spermatogonia: </li></ul><ul><ul><li>Replicate initially by mitosis. </li></ul></ul><ul><ul><li>Produce two cells </li></ul></ul><ul><li>One becomes a primary spermatocytes undergoes meiosis: </li></ul><ul><ul><li>2 nuclear divisions. </li></ul></ul><ul><ul><li>2 nd meiotic division produce 4 spermatids. </li></ul></ul>www.freelivedoctor.com
  32. 32. Spermiogenesis <ul><li>Maturation of spermatozoa. </li></ul><ul><li>Cytoplasm is pinched off and ingested by the Sertoli cell cytoplasm. </li></ul>www.freelivedoctor.com
  33. 33. Sertoli Cells <ul><li>Blood-testes barrier: </li></ul><ul><ul><li>Prevents autoimmune destruction of sperm. </li></ul></ul><ul><ul><li>Produce FAS ligand which binds to the FAS receptor on surface to T lymphocytes, triggering apoptosis. </li></ul></ul><ul><li>Secretes inhibin. </li></ul><ul><li>Phagocytize residual bodies: </li></ul><ul><ul><li>Transmit information molecules from germ cells to Sertoli cells. </li></ul></ul><ul><li>Secrete ABP (androgen-binding protein): </li></ul><ul><ul><li>Binds to testosterone and concentrates testosterone in the tubules. </li></ul></ul>www.freelivedoctor.com
  34. 34. Hormonal Control of Spermatogenesis <ul><li>Testosterone required for completion of meiosis and spermatid maturation. </li></ul><ul><li>Testes secrete paracrine regulators: </li></ul><ul><ul><li>IGF-1. </li></ul></ul><ul><ul><li>Inhibin. </li></ul></ul><ul><li>FSH necessary in the later stages of spermatid maturation. </li></ul>www.freelivedoctor.com
  35. 35. Male Accessory Organs <ul><li>Epididymis: </li></ul><ul><ul><li>Maturational changes. </li></ul></ul><ul><ul><li>Resistance to pH changes and temperature. </li></ul></ul><ul><ul><li>Storage. </li></ul></ul><ul><li>Prostate secretes: </li></ul><ul><ul><li>Alkaline fluid. </li></ul></ul><ul><ul><li>Citric acid. </li></ul></ul><ul><ul><li>Ca ++ . </li></ul></ul><ul><ul><li>Coagulation proteins. </li></ul></ul><ul><li>Seminal vesicles secrete: </li></ul><ul><ul><li>Fructose. </li></ul></ul>www.freelivedoctor.com
  36. 36. Erection, Emission, and Ejaculation <ul><li>Erection: </li></ul><ul><ul><li>Increased vasodilation of arterioles. </li></ul></ul><ul><ul><li>NO is the NT. </li></ul></ul><ul><ul><li>Blood flow into the erectile tissues of the penis. </li></ul></ul><ul><ul><li>Parasympathetic </li></ul></ul><ul><li>Emission: </li></ul><ul><ul><li>Movement of semen into the urethra. </li></ul></ul><ul><ul><li>Sympathetic </li></ul></ul><ul><li>Ejaculation: </li></ul><ul><ul><li>Forcible expulsion of semen from the urethra out of the penis. </li></ul></ul><ul><ul><li>Sympathetic </li></ul></ul>www.freelivedoctor.com
  37. 37. Female Reproductive System <ul><li>Ovaries: </li></ul><ul><ul><li>Contain large number of follicles which enclose ova. </li></ul></ul><ul><ul><li>Extensions called fimbriae partially cover each ovary. </li></ul></ul><ul><ul><li>At ovulation, secondary oocyte is extruded. </li></ul></ul>www.freelivedoctor.com
  38. 38. Female Reproductive System <ul><li>Fallopian (uterine) tubes: </li></ul><ul><ul><li>Ova drawn into the tube by cilia. </li></ul></ul><ul><li>Uterus: </li></ul><ul><ul><li>Womb. </li></ul></ul><ul><ul><li>Endometrium shed during menstruation. </li></ul></ul><ul><li>Vagina: </li></ul><ul><ul><li>Cervical mucus plug. </li></ul></ul>www.freelivedoctor.com
  39. 39. Ovarian Cycle <ul><li>5 mo. gestation ovaries contain 6-7 million oogonia. </li></ul><ul><li>Oogenesis arrested in prophase of 1 st meiotic division (primary oocyte). </li></ul><ul><li>Apoptosis occurs: </li></ul><ul><ul><li>2 million primary oocytes at birth. </li></ul></ul><ul><ul><li>400,000 primary oocytes at puberty. </li></ul></ul><ul><li>400 oocytes ovulated during the reproductive years. </li></ul>www.freelivedoctor.com
  40. 40. Ovarian Cycle <ul><li>Primary oocytes contained in primary follicles. </li></ul><ul><ul><li>FSH stimulates cell growth. </li></ul></ul><ul><li>Develop into secondary follicles. </li></ul><ul><li>Fusion of its vesicles into the antrum. </li></ul><ul><li>Mature graafian follicle: </li></ul><ul><li>1 st meiotic division completed (secondary oocyte). </li></ul>www.freelivedoctor.com
  41. 41. www.freelivedoctor.com
  42. 42. Ovarian Cycle <ul><li>Secondary oocyte: </li></ul><ul><li>Under FSH stimulation: </li></ul><ul><ul><li>Theca cells secrete testosterone. Granulosa cells: contain the enzyme aromatase to convert testosterone into estrogen. </li></ul></ul>www.freelivedoctor.com
  43. 43. Ovulation <ul><li>Graafian follicle forms bulge on surface of ovary. </li></ul><ul><li>Extrudes secondary oocyte into the uterine tube. </li></ul><ul><li>Empty follicle becomes corpus luteum and secretes: </li></ul><ul><ul><li>Progesterone. </li></ul></ul><ul><ul><li>Estrogen. </li></ul></ul><ul><ul><li>If not fertilized becomes corpus albicans. </li></ul></ul>www.freelivedoctor.com
  44. 44. Menstrual Cycle <ul><li>3 phases: Ovarian </li></ul><ul><ul><li>Follicular Phase </li></ul></ul><ul><ul><li>Ovulation </li></ul></ul><ul><ul><li>Luteal Phase </li></ul></ul><ul><li>Duration approximately 28 days. </li></ul><ul><li>Day 1 is the first day of menstruation. </li></ul>www.freelivedoctor.com
  45. 45. Follicular Phase <ul><li>FSH: </li></ul><ul><li>Stimulates production of FSH receptors on granulosa cells. </li></ul><ul><ul><li>Follicles grow and become secondary follicle. </li></ul></ul><ul><li>Granulosa cells secrete estradiol. </li></ul><ul><li>Increases sensitivity of FSH receptors. </li></ul><ul><li>FSH and estradiol stimulate production of LH receptors in graafian follicle. </li></ul>www.freelivedoctor.com
  46. 46. Follicular Phase <ul><li>Rapid rise in estradiol: </li></ul><ul><ul><li>Negative feedback on LH and FSH. </li></ul></ul><ul><li>Hypothalamus increase frequency of GnRH pulses. </li></ul><ul><li>Augments the ability of anterior pituitary to respond to GnRH to increase LH secretion. </li></ul>www.freelivedoctor.com
  47. 47. Follicular Phase <ul><li>Positive feedback: </li></ul><ul><ul><li>LH surge begins 24 hours before ovulation. </li></ul></ul><ul><ul><li>Triggers ovulation. </li></ul></ul><ul><li>FSH increase stimulates development of new follicles. </li></ul>www.freelivedoctor.com
  48. 48. Ovulation <ul><li>Under FSH, graafian follicle grows large and thin-walled. </li></ul><ul><ul><li>Triggers LH surge. </li></ul></ul><ul><li>Wall of graafian follicle ruptures. </li></ul><ul><li>Day 14. </li></ul><ul><li>Ist meiotic division is completed. </li></ul>www.freelivedoctor.com
  49. 49. Luteal Phase <ul><li>LH stimulates formation of the empty follicle into corpus luteum. </li></ul><ul><li>Corpus luteum secretes: </li></ul><ul><ul><li>Progesterone: </li></ul></ul><ul><ul><li>Plasma concentration rapidly rises. </li></ul></ul><ul><ul><li>Estradiol. </li></ul></ul><ul><li>Negative feedback on LH and FSH. </li></ul><ul><li>Inhibin: suppress FSH. </li></ul>www.freelivedoctor.com
  50. 50. Luteal Phase <ul><li>Corpus luteum regresses unless fertilization occurs: </li></ul><ul><ul><li>Estradiol decreases. </li></ul></ul><ul><ul><li>Progesterone decreases. </li></ul></ul><ul><li>Withdrawal of estradiol and progesterone cause menstruation to occur. </li></ul>www.freelivedoctor.com
  51. 51. www.freelivedoctor.com
  52. 52. www.freelivedoctor.com
  53. 53. Endometrial Changes <ul><li>3 phases of endometrium changes: </li></ul><ul><ul><li>Proliferative phase. </li></ul></ul><ul><ul><li>Secretory phase. </li></ul></ul><ul><ul><li>Menstrual phase. </li></ul></ul>www.freelivedoctor.com
  54. 54. Proliferative Phase <ul><li>Ovary is in follicular phase. </li></ul><ul><li>Estradiol stimulate growth of endometrium. </li></ul><ul><li>Spiral arteries develop. </li></ul><ul><li>Stimulate production of receptor proteins for progesterone. </li></ul><ul><li>Cornification of vaginal epithelium occurs. </li></ul>www.freelivedoctor.com
  55. 55. Secretory Phase <ul><li>Ovary is in luteal phase. </li></ul><ul><li>Progesterone stimulates development of uterine glands, which become engorged with glycogen. </li></ul><ul><li>Endometrium becomes thick, vascular and spongy. </li></ul><ul><li>Cervical mucus thickens and becomes sticky. </li></ul>www.freelivedoctor.com
  56. 56. Menstrual Phase <ul><li>Progesterone cause constriction of spiral arteries. </li></ul><ul><li>Necrosis and sloughing of endometrium occurs. </li></ul><ul><li>Lasts 1-5 days. </li></ul>www.freelivedoctor.com
  57. 57. www.freelivedoctor.com
  58. 58. Menopause <ul><li>Cessation of ovarian activity. </li></ul><ul><li>Age ~ 50 years. </li></ul><ul><li>Ovaries depleted of follicles. </li></ul><ul><li>Estradiol and inhibin withdrawl causes hot flashes, and atrophy of the vaginal wall. </li></ul><ul><li>LH and FSH increase. </li></ul>www.freelivedoctor.com
  59. 59. Fertilization <ul><li>Ejaculation 300 million sperm, 100 reach (uterine) fallopian tube. </li></ul><ul><li>Fertilization occurs in the uterine tubes </li></ul><ul><li>Acrosomal reaction: </li></ul><ul><ul><li>Acrosome of sperm contains hyaluronidase, an enzyme that digests a channel through zona pellucida. </li></ul></ul><ul><li>Sperm fuses with ovum cell membrane. </li></ul>www.freelivedoctor.com
  60. 60. Fertilization <ul><li>As fertilization occurs, secondary oocyte completes 2 nd meiotic division. </li></ul><ul><li>Sperm enters ovum cytoplasm. </li></ul><ul><li>Ovum nuclear membrane disappears, zygote formed. </li></ul>www.freelivedoctor.com
  61. 61. Blastocyct Formation <ul><li>Cleavage: </li></ul><ul><ul><li>30-36 hrs. after fertilization the zygote divides by mitosis. </li></ul></ul><ul><li>Blastocyst develops: </li></ul><ul><ul><li>Inner cell mass: fetus. </li></ul></ul><ul><ul><li>Surrounding chorion: trophoblasts form placenta. </li></ul></ul>www.freelivedoctor.com
  62. 62. Implantation <ul><li>6 th day after fertilization, blastocyst attaches to uterine wall. </li></ul><ul><li>Blastocyst secretes enzymes that allow blastocyst to burrow into endometrium. </li></ul><ul><li>Trophoblast cells secrete hCG. </li></ul>www.freelivedoctor.com
  63. 63. hCG <ul><li>Human chorionic gonadotropin. </li></ul><ul><li>Trophoblast cells secrete hCG. </li></ul><ul><li>Signals corpus luteum not to degenerate until placenta secretes adequate [hormone]. </li></ul><ul><li>Effects similar to LH. </li></ul><ul><li>Basis of pregnancy test. </li></ul>www.freelivedoctor.com
  64. 64. Placenta <ul><li>Syncytiotrophoblast secretes enzymes that create blood filled cavities in the maternal tissue. </li></ul><ul><li>Cytotrophoblast then from projections (villi) that grow into the venous blood. </li></ul><ul><ul><li>Producing chorion frondosum on the side that faces the uterine wall. </li></ul></ul><ul><li>Other side of chorion bulges into the uterine cavity. </li></ul>www.freelivedoctor.com
  65. 65. Placental Changes <ul><li>Decidual reaction: </li></ul><ul><ul><li>Endometrial growth. </li></ul></ul><ul><ul><li>Accumulation of glycogen. </li></ul></ul><ul><li>Decidua basalis: maternal tissue in contact with the chorion frondosum. </li></ul><ul><li>Maternal and fetal blood do not mix. </li></ul>www.freelivedoctor.com
  66. 66. Amnion <ul><li>Envelop the embryo. </li></ul><ul><li>Amnionic fluid contains sloughed cells of the fetus. </li></ul>www.freelivedoctor.com
  67. 67. Placenta Function <ul><li>Gas exchange: </li></ul><ul><ul><li>0 2 and C0 2 . </li></ul></ul><ul><li>Nutrient exchange. </li></ul><ul><li>Waste exchange. </li></ul><ul><li>Synthesis of proteins and enzymes. </li></ul>www.freelivedoctor.com
  68. 68. Placental Hormones <ul><li>hCS: </li></ul><ul><li>Chorionic somatomammotropin. </li></ul><ul><li>GH effects. </li></ul><ul><li>Diabetic-like effect: </li></ul><ul><ul><li>Glucose sparing effect. </li></ul></ul><ul><ul><li>Polyuria. </li></ul></ul><ul><ul><li>Lipolysis. </li></ul></ul>www.freelivedoctor.com
  69. 69. Placental Hormones <ul><li>Fetal-placental unit: </li></ul><ul><ul><li>Placenta must cooperate with the adrenal cortex in the fetus to produce estrogen. </li></ul></ul><ul><li>Estrogen stimulates: </li></ul><ul><ul><li>Endometrial growth. </li></ul></ul><ul><ul><li>Inhibit prolactin secretion. </li></ul></ul><ul><ul><li>Growth of mammary ducts. </li></ul></ul><ul><ul><li>Enlargement of mother’s uterus. </li></ul></ul>www.freelivedoctor.com
  70. 70. Placental Hormones <ul><li>Progesterone: </li></ul><ul><ul><li>Suppresses uterine contractions. </li></ul></ul><ul><ul><li>Stimulates uterine growth . </li></ul></ul><ul><ul><li>Suppresses LH and FSH. </li></ul></ul><ul><ul><li>Stimulate development of alveolar tissue of the mammary gland. </li></ul></ul>www.freelivedoctor.com
  71. 71. Parturition <ul><li>Estrogen in late pregnancy: </li></ul><ul><ul><li>Increases amount of oxytocin stored. </li></ul></ul><ul><ul><li>Stimulate production of oxytocin receptors in myometrium. </li></ul></ul><ul><ul><li>Stimulate prostaglandin production. </li></ul></ul><ul><li>Uterine contractions: </li></ul><ul><ul><li>Oxytocin. </li></ul></ul><ul><ul><li>Prostaglandins. </li></ul></ul>www.freelivedoctor.com
  72. 72. Lactation <ul><li>Hypothalamus releases PRH. </li></ul><ul><li>Anterior pituitary releases prolactin: </li></ul><ul><ul><li>Stimulate milk production. </li></ul></ul><ul><li>Oxytocin needed for “milk letdown”. </li></ul>www.freelivedoctor.com
  73. 73. www.freelivedoctor.com
  74. 74. www.freelivedoctor.com
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