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63 Cards in this Set
- Front
- Back
What parts of the body make up the HPG axis?
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hypothalamus
anterior pituitary gonads |
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What are the steps leading to the release of the ovarian and testicular hormones?
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hypothalamus synthesize and secrete gonadotropin releasing hormone (GnRH)
GnRH stimulates anterior pituitary to release luteinizing hormone (LH) and follicle stimulating hormone (FSH) LH and FSH stimulate gonads to release ovarian and testicular hormones |
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What modulates the secretion of GnRH?
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neural input form CNS
circulating gonadal hormones |
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What type of secretion does GnRH have?
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pulsatile
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Why dose secretion of GnRH have to be pulsatile?
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pulsatile stimulate release of FSH and LH
nonpulsatile inhibit release of LH and FSH |
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What are the clinical uses of GnRH?
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diagnostic studies to distinguish between hypogonism due to pituitary or hypothalamus
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What am I:
a GnRH analog longer acting used for non-pulsatile secretion to inhibit release of LH and FSH? |
leuprolide
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What type of pituitary cells are LH and FSH produced from?
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gonadotrophs
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What hormone is produced by the placenta?
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human chorionic gonadotropin (hCG)
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What is leuprolide used for?
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diagnosis of prostate and ovarian cancer
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What chain (alpha or beta) do all 3 gonadotrpins have in common?
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alpha chain
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What chain (alpha or beta) is different in each gonadotropin?
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beta chain
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What chain of the gonadotropin provides specificity for receptor interactions?
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beta chain
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What type of receptors are gonadotropin receptors?
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g protein coupled
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Which gonadotropin receptor binds to LH and hCG?
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LH receptor
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What am I:
in women, stimulate growth of ovariam follicles in men, regulate spermatogenesis |
FSH
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What am I:
in women, regulate production of estrogen and progesterone, is required for ovulation in men, stimulates lefdig cells of testest to produce testosterone |
LH
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What is the clinical use of LH and FSH?
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women: ovulation induction
men: treatment of infertility |
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What ovarian hormone does not have positive feedback?
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progesterone
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Where do ovarian hormones feedback to?
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hypothalamus
anterior pituitary |
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What hormone is produced by ovaries?
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progesterone and estrogen
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What are the natural estrogens?
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17-beta-estradiol
estrone estriol |
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What natural estrogen is the most biologically active?
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estradiol
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What natural estrogen is formed in the liver on in the peripheral tissues of some androgen?
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estrone
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What natural estrogen is produced in large amounts during pregnancy by the placenta and the fetal adrenal glands - is not found in men?
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estriol
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What type of receptors are estrogen receptors?
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nuclear receptors
there are 2 types |
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What are circulating estrogens mostly protein bound to?
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alpha globulin
sex hormone binding globulin albumin |
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How do estrogens become unbound (activated)?
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metabolized to active metabolite in liver
undergo entero-hepatic cycling in small intestine |
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What are the synthetic estrogens?
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ethinyl estradiol
estradiol valerate |
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What are the clinical uses of synthetic estradiol?
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oral contraceptives - increase oral effectiveness when compared to natural estrogens
hormone replacement therapy |
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What is the mechanism of action of estrogen?
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free estrogen diffuse across membrane and bind to ER-alpha or ER-beta in the nucleus or cytosol
ER-estrogen dimerize and bind to ERE to regulate target gene transcription/translation |
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What are teh CV and CNS effects of estrogen?
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maintain blood vessel function
increase bone density increase liver synthesis of coagulation factors behavioral and mood effects |
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What are the side effects of estrogen therapy?
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uterine bleeding
carcinogenic action increased blood coagulation factors |
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What are the renal effects of progesterone?
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competes with aldosterone at minercortocoid recepter
decrease sodium reabsorption |
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What are the synthetic progestins?
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hydroxyprogesterone
medroxyprogesterone L-norgestrel desogestrel |
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What are the clinical uses of progestins?
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contraceptives
hormone replacement therapy |
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What is the MOA of progesterone?
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similiar to estrogen, but with PR-alpha, PR beta, PRE
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What are the endometrial effects of progesterone?
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decreases estrogen-driven endometrial proliferation leading to developement of secretory changes in endometrial cells
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What are the CNS effects of progesterone?
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increase basal body temp
causes drowsiness |
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What is the side effect of progesterone?
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increase bp
synthetic progestins have adrogenic effects |
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What are the combination oral contraceptives?
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ethinyl estradiol
L-Norgestril Desogestrel |
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What is the mechanism of action of combination oral contraceptives?
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inhibits FSH and LH from anterior pituitary resulting in inhibition of ovulation
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What results from the chronic use of combination oral contraceptives?
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depressed ovarian function
decrease ovarian size |
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What are the side effects of combination oral contraceptives?
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Nausea
edema headache DVT/PE, MI, stroke in smokers reduce risk of endometrial and ovarian cancers with estrogen alone |
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what are the progestrin only contraceptives?
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L-Norgestrel
medroxyprogestrone |
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What is the MOA of progestin only contraceptives?
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thickening of cervical mucus and endometrial changes
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What are the side effects of progestin only contraceptives?
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irregular/unpredictable bleeding
acne headache mood changes weight gain |
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What am I:
hormone replacement therapy used for postmenopausal women with a uterus |
estrogen + progestin
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What is the benefit of using estrogen + progestrin?
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reduce risk of estrogen-induced uterine cancer
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What am I:
hormone replacement therapy used for postmenopausal women without a uterus? |
estrogen alone
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What is the benefit of using estrogen alone in women without a uterus?
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risk of estrogen-induced uterine cancer no longer exist
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What estrogens are used for hormone replacement therapy?
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ethinyl estradiol
conjugated equine estrogen (Premarin) |
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True or False:
premarin is a prodrug that is converted into estradiol |
True
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What is the side effects of equilin and equilenin (minor forms of premarin)?
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cytotoxins that cause DNA damage
cause cancer |
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What is the major form of premarin?
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estrone
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What testicular hormone is the main stimulus for LH secretion?
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testoterone
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How is testerone activated?
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coverted to dihydor-testosterone by 5-alpha-reductase
coverted to estradiol by aromatase |
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What is the MOA of testosterone and DHT?
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binds to androgen receptors (AR)
results in changed protein synthesis |
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What has a higher binding affinity to androgen receptors, DHT or testosterone?
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DHT
|
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What is required for the development and function of male reproductive organs and development of male secondary sexual characteristics?
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testoterone and DHT
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Testosterone effect is mediated through what hormone?
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estradiol
|
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What are the anabolic steroids?
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alkylated androgens
methytestosterone oxandrolone nandrolone |
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What are the side effects of anabolic steroids?
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diminished fertility
hepatic dysfunction |