Physiology 5 RS problem set

  1. In the first 10 days of the menstrual cycle, how does estrogen affect the pulsatile release of GnRH from the hypothalamus?
    - decreases GnRH release but does not alter its pulsatile pattern
  2. Withdrawal of which of the following hormones results in menstruation?
  3. Immunization to produce antibodies that would bind to FSH and negate its activity is being investigated as a potential male contraceptive. Men immunized in this manner would exhibit ____.
    decreased sperm levels
  4. An adult male who can not produce testosterone since early childhood and who has not been treated for this condition will ____.
    be taller than average - he will grow taller than average because closure of the epiphysial plates is dependent on testosterone.
  5. The two essential hormones for the production of sperm (spermatogenesis) are _____.
    FSH and testosterone
  6. In males and females, secretion of luteinizing hormone (LH) by the pituitary is regulated by ____.
    Gonadotrophin Releasing Hormone (GnRH)
  7. In a female patient with an inactivating mutation of the estrogen receptor genes (both alpha and beta), one would expect _____.
    A low progesterone receptor content in all estrogen target cells; high circulating estrogen, LH and FSH concentrations; and no mid-cycle LH and FSH surge
  8. Steroid hormones such as estrogen and progesterone _____.
    freely diffuse through cell membranes.
  9. Explain the roles of GnRH, LH and FSH in the production of gametes in the human male and female. What hormone(s) are negatively regulated by inhibin in the male and in the female?
    • GnRH from the hypothalamus increases secretion of LH and FSH from the pituitary in both sexes.
    • LH promotes the secretion of testosterone from the theca cells of the female and from the Leydig cells of the male.
    • FSH is necessary for the development of the ovarian follicle (granulosa cells) that surround the ova in the female and for the development of the sperm in the males.
    • Inhibin negatively regulates FSH in the male and in the female.
  10. In polycystic ovary disease the ovaries fail to ovulate. This is due to high circulating levels of androgens. What cell type in the ovary secretes androgens? What hormone triggers ovulation?
    Theca Interna; mid cycle LH spike
  11. Hormonal therapy of prostate cancer showed that 50% of DHT was left in the prostate of males who had their testicles removed. Yet 95% of their blood testosterone levels were reduced by castration. In the absence of testicles, what other tissue source continued to provide androgens to the prostate?
    The adrenal glands secrete DHEA which is converted to DHT within the prostate. In normal males, this is a minor source of androgen.
  12. Predict the level of FSH in the post-menopausal female.
    Increased b/c have lost a negative feedback loop
  13. Why do athletes who dose themselves with excess amounts of weak androgens (such as DHEA) develop breast tissue? What enzyme is involved?
    Increase of estrogen in breast tissue b/c of aromatase
  14. In a young boy diagnosed with precocious puberty, puberty is best delayed by the administration of a long-lasting ____. Why?
    GnRH receptor agonist – binds to receptor and makes work so pushing the axis but will increase the negative feedback so down regulate LH and FSH

    Don't want to push Testosterone receptor agonist – bc will make even more male
Card Set
Physiology 5 RS problem set