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2012-04-29 21:38:01
male reproductive system

male reproductive system
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  1. describe the structure and fxn of the male external genitalia:
    • scrotum
    • pouch of skin, muscle, connective tissue
    • contains: 2 testes (compartmentalized), spermatic cord (vessels, nerves, ductus deferens), creamaster muscle, ductus deferens, epididymus, testes, dartos muscle
    • fxn: holds testes, keeps @ 35 degrees celcus

    • creamaster muscle
    • when cold, contracts
    • brings testes closer to the body, when warm relaxes

    • dartos muscle
    • same as creamaster muscle
    • contraction decreases surface area
    • decreases heat loss

    • pampiniform plexus
    • network of veins
    • acts as countercurrent heat exchanger
    • removes heat from arterial blood (makes 2 degrees cooler

    • penis
    • deposit semen into vagina
    • 3 types of erectile tissue - tiny blood sinuses fill during erection - corpus cavernosum, corpus spongiosum, prepuce
    • prepuce - removed during circumcision
    • dorsal side = anterior
  2. list the fxn of the reproduction system:
    production of gametes

    • male: produces sperm + inseminate women
    • female: produce eggs + receive sperm, shelters embryo + nourish offspring
  3. describe the primary and secondary sex organs of males and females:
    • primary organs (gonads): male - testes, female - ovaries
    • secondary organs: necessary for reproduction, male - ducts, glands, penis, female - uterine tubes, uterus, vagina
  4. describe the structure and fxn of the testes including sertoli cells and leydig cells:
    fxn: production of sperm + testerone

    • structure
    • seminiferous tubules: sperm production (250M long)
    • rete testis: network of tubes, sperm is partially mature here, sperm move inside by fluid pressure, DO NOT SWIM THERE

    • leydig interstial cells
    • produce testerone

    • sertoli cells
    • protects developing sperm
    • forms blood/teste barrier
    • prevents immune/chemcial destrcution
    • promote sperm development - provides nutrients, growth factors, removes wastes, provides fluid to move sperm along
  5. trace the path of sperm from the site of production thru the spermatic duct system to the exterior of the body:
    • efferent ductules: ~ 12 cillia to propel sperm along
    • epididymis: sperm maturation (~20 days), sperm storage (40-60 days)
    • ductus deferens: most sperm stored
    • ejactuatory duct: passes thru prostate

    pathways: urethra - shared by urinary + reproductive systems (cant pass at the same time)
  6. describe the structure and fxn of the accessory glands (seminal vessicles, prostate gland, bulbourethral gland) including their contributions to semen and their order of contraction:
    • seminal vessicles
    • 2x
    • size of little finger
    • yellowish secretions (60% of semen)

    • prostate gland
    • size of walnut
    • 30% of semen, think milky secretions
    • cancer - 2nd highest in males, high cure rate if found early

    • bulbourethral (cowpers) gland
    • empties ito urethra (inner end of penis)
    • produces clear, slippery fluid during arousal
    • lubriacates head of penis
    • neutralizes acidity of any residual urine
  7. review spermatogenesis including the stages of cell progression from spermatogonia into mature sperm:
    • net result: 4 daughter cells (sperm), each haploid, 23 unpaired chromosomes
    • germ cells > spermatogonia > primary spematocytes > 1st meiotic division > secondary spermatocytes > 2nd meiotic division > spermatides > differentiation - spermatoza **1st meiotic division provides genetic diversity (prophase)

    • some spermatogonia remain behind as stem cells
    • basement membrane of seminiferous tubules
    • type A: replicates
    • type B: differeniates - spermatogonium - outside the blood teste barrier, provides protection against own antibodies, sustentacular cell-sertoli cell
    • primary spermatocyte - inside BTB before meiosis I
    • secondary spermatocyte - meiosis II
    • spermatide - sprouts tail, loses cytoplasm/bridges
    • spermatogensis - 4 spermatids result/spermatogonia (young adult 300K/min, 600 ml/day)

    *migrate to center lumen dividing + differenating, takes ~ 74 days
  8. describe the structure of mature sperm and the fxn of its components:
    • acrosome: contains enzymes needed for fertilization
    • the head: all most all nucleus
    • midpiece of the tail: large, mumerous mitochondria, energy for motility
    • endpiece of tail: propulsion ~ 3mm/min, 30 mins till fallopian tube
    • final maturation/activation occurs in the female
  9. discuss the formation of semen and describe the fnx of the components of semen:
    seed, ~ 2-5 ml/ejaculation

    • 60% seminal vessicle fluid
    • proseminogelin, prostaglandins, alkaline phosphates (enzymes), fructose

    • 30% prostate fluid
    • clotting enzymes, serine protease (enzyme), alkaline mucus

    • 10% sprem/spermatic duct serections
    • 50-120 M/ml
    • trace amount of bulbouretheral fluid

    • seminoglein: clotting enzyme + proseminogelin (precursor), keeps semen in vagina
    • serine protease: aka PSA, secreted 30 min later, breaks down seminogelin, liquifies semen, activating sperm
    • prostagladins: thins vaginal mucus, easier sperm motility, stimulates uterine contractions (helps sperm move up tubes)
    • alkaline phosphate: pH buffer (pH changes from ~ 4 to 7.5), helps activate sperm
    • fructose: sperm energy source
  10. identify the target cells and effects of GnRH, FSH, LH, and inhibin:
    • spermatogensis: activation requires testerone + FSH, to shut down requires inhibin
    • hyopthalamus: secretes GnRH > GnRH in hypothalmo-pituitary protal vessicle> anterior pituitary secretes FSH, LH> FSH stimulates sertolie cell - stiumulates spermatogensis, and produces inhibin (negative feedback on FSH only) > LH stimulates leydig cells- testoerone, stimulates sertoli cell and engative feedback on LH and Hypothalamus
    • 2ndary sex characteristics: reproductive tract + other ograns repsond to testerone
    • inhibin decreases FSH (NOT LH)
  11. list the fnx of testosterone:
    • testosterone
    • 1st trimester: fertilization
    • 2nd trimester: birth (increase)
    • 13 yrs/puberty: increase GnRH, LH, testosterone
    • adult: level secretion
    • 60 yrs: decrease secretion, decrease libido, sperm motility
  12. list the fxn of testicluar andorgens
    testciular androgensgrowth and maintence of sex organsspermatogensisbody growth - protein synthesis, especially bone/muscle/vocal cordspubic/axiallary/facial hair , darker, thicker skinRBCs/metabolismlibido (sex drive)+ aggression
  13. desribe the phases of the male sexual cycle including regulation by the nervous system:
    • emotions: powerful part of stimulation
    • increased HR, BP, ventilation
    • stimulation > increased PSNS > nitrous oxide - vasodilation (increase blood flow) > trabecular muscle of erectile tissue, relaxes; allows for engorgement of erectile tissue > penis becomes erect
  14. Which of the following are the male primary sex organs? (Choose all that apply)

    seminal vesicles
    vas deferens
  15. Which of the following are mechanisms used by the body to COOL the testicles? (Choose all that apply)

    relaxation of dartos muscle
    contraction of the cremaster muscle
    decreased blood flow
    countercurrent heat exchange
    • relaxation of dartos muscle
    • countercurrent heat exchange
  16. Which of the following produce testosterone?

    Leydig cells
    sperm cells
    anterior pituitary
    Sertoli cells
    Leydig cells
  17. Which of the following produces fluid to neutralize urine in the urethra?

    efferent ductules
    sustentacular cells
    bulbourethral glands
    seminal vesicles
    prostate gland
    bulbourethral glands
  18. In spermatogenesis, before meiosis I occurs, the __________ must first move inside the blood-testes barrier. At the end of meiosis II a total of four ________ are produced.

    spermatids, spermatogonium
    secondary spermatocytes, spermatids
    spermatogonia, primary spermatocytes
    spermatids, mature sperm cells
    primary spermatocytes, spermatids
    primary spermatocytes, spermatids
  19. Which of the following ensures semen does not flow out of the vagina?

    a large sperm count
    vaginal mucus
    serine protease
    anti-gravity skivvies
  20. Which of the following suppresses FSH secretion?

    follicle stimulating hormone by negative feedback
    lutenizing hormone
    androgen-binding protein
    gonadotropin-releasing hormone
  21. Which of the following stimulates the production of pubic hair and facial hair?

  22. Erectile tissues become engorged with blood when the _______ triggers the release of the signaling molecule _______, which causes relaxation/dilation of the arteries in the penis.

    somatic nervous system; seminogelin
    SNS; serine protease
    PSNS; nitric oxide
    PSNS; prostaglandin
    SNS; bicarbonate
    PSNS; nitric oxide