Endocrinology/Exam 1 sample questions
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1. Oxytocin that acts on the lactotropes is secreted by what cells?
a. Magnocellular neurons of the paraventricular nucleus b. Magnocellular neurons of the supraoptic nucleus c. Parvocellular neurons of the paraventricular nucleus d. Parvocellular neurons of the supraoptic nucleus e. Dopamine-secreting cells of the arcuate nucleus
2. Which area produces a hormone with tonic inhibitory influence on prolactin secretion?
a. Arcuate nucleus b. Paraventricular nucleus c. Supraoptic nucleus d. Medial preoptic nucleus e. Periventricular nucleus
3. Where is GnRH produced?
a. Medial preoptic nucleus b. Ventromedial hypothalamus c. Arcuate nucleus d. A and B e. A and C
4. Which hormone does not require a second messenger system for its activity?
a. Gonadotropin-releasing hormone b. Corticotropin c. Growth hormone d. Progesterone e. Prolactin
5. All of the following statements about GH secretion and its pulsatility are true EXCEPT:
a. Testosterone causes higher peaks. b. Testosterone causes lower troughs. c. Testosterone elevates somatostatin levels. d. GH levels decrease after the onset of sleep. e. Basal GH levels are higher in females than males.
6. Which of the following is most directly responsible for stimulating growth in utero?
a. GH b. IGF-1 c. IGF-2 d. HPL (human placental lactogen) e. HCS (human chorionic somatomammotropin)
7. All of the following would inhibit human growth hormone secretion EXCEPT:
a. Hypolipidemia b. Hyperglycemia c. HPL d. HCS e. Stress
8. All of the following might be expected in a patient with Laron dwarfism EXCEPT:
a. Increased GH b. Increased IGF-1 c. Decreased stature d. Decreased muscle growth e. GH resistance
9. Regarding the pituitary gonadotropins, which of the following statements is true?
a. GnRH stimulates FSH release more than it stimulates LH release. b. Long-loop negative feedback from LH inhibits GnRH release. c. Ultrashort-loop negative feedback from LH inhibits GnRH release. d. Inhibin is produced by Sertoli cells and inhibits LH secretion. e. Testosterone inhibits LH secretion more than it inhibits FSH secretion.
10. All of the following statements are true EXCEPT:
a. LH and FSH are released in a pulsatile manner. b. Long-loop negative feedback is not required for LH and FSH pulsatility. c. Pulsatile LH and FSH release is necessary to avoid receptor desensitization. d. An ovarectomized rat will not exhibit pulsatile LH and FSH release. e. Pulsatility of LH and FSH release is governed by the medial preoptic and arcuate nuclei.
11. Regarding ovarian secretions, all of the following statements are true EXCEPT:
a. The principal hormonal secretions of theca cells are testosterone and androstenedione. b. Theca cells contain large amounts of aromatase. c. Granulosa cells contain large amounts of aromatase. d. Theca lutein cells produce estrogens. e. Granulosa lutein cells produce progesterone.
12. Regarding the modulation of GnRH release, which statement is false?
a. Beta-endorphin stimulates GnRH release. b. Stress inhibits the release of GnRH by stimulating the release of beta-endorphin. c. Norepinephrine stimulates GnRH release more so than does epinephrine. d. Neurons that release GnRH receive modulatory input. e. LH and FSH exert short-loop negative feedback on GnRH release.
13. At physiologically low levels of estrogen, which of the following is true?
a. GnRH release is not pulsatile. b. GnRH release is inhibited by long-loop positive feedback. c. GnRH release from the medial preoptic nucleus is feedback-stimulated. d. GnRH release from the arcuate nucleus is feedback-inhibited. e. GnRH release is inhibited more by progesterone than by estrogen.
14. At physiologically high levels of estrogen in females, all of the following are true EXCEPT:
a. Estrogen negatively feeds back on the arcuate nucleus. b. Negative long-loop feedback from estrogen on the arcuate nucleus becomes positive. c. Negative long-loop feedback from estrogen on the medial preoptic nucleus becomes positive. d. The GnRH surge depends upon high estrogen levels in a rising phase. e. A surge in FSH levels results.
Answers:
1. c 2. a 3. e 4. d 5. d 6. c 7. a 8. b 9. e 10. d 11. b 12. a 13. d 14. b
