Hormone feedback loop mechanisms and reproductive cycle physiology tested on USMLE Step 1, distinct from the disease-focused Endocrine and Reproductive Medicine decks.
About this set
34 basic cards for USMLE Step 1 Physiology. Set 3 of 9 in USMLE Physiology. It opens with "In the HPA axis, the hypothalamus releases ____, which stimulates the anterior" and "What is the principal negative feedback target of cortisol in the HPA axis?". Study it alongside the other USMLE Step 1 sets below.
34 cards · basic cards · AI-written, checked twice. Edit anything.
- In the HPA axis, the hypothalamus releases ____, which stimulates the anterior pituitary to secrete ACTH.
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CRH- What is the principal negative feedback target of cortisol in the HPA axis?
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The hypothalamus and anterior pituitary (suppressing CRH and ACTH release)- In the HPT axis, TRH from the hypothalamus stimulates the anterior pituitary to release ____.
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TSH- What effect do circulating T3 and T4 have on TSH and TRH secretion?
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Negative feedback, they suppress TSH and TRH release- What pattern of GnRH secretion is required to stimulate normal LH and FSH release?
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Pulsatile secretion- What happens to LH and FSH secretion when GnRH is given continuously instead of pulsatile?
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LH and FSH secretion decreases due to receptor downregulation- Which hormone surge directly triggers ovulation?
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LH surge- Under what estrogen condition does estrogen switch from negative to positive feedback on GnRH and LH release?
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When estrogen is high and sustained for about 48 hours, in the late follicular phase- What effect does estrogen have on gonadotropin release at low to moderate levels?
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Negative feedback, it suppresses LH and FSH release- How does progesterone affect GnRH pulse frequency during the luteal phase?
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It decreases GnRH pulse frequency (negative feedback)- Which ovarian cell type is the principal target of FSH?
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Granulosa cells- According to the two cell, two gonadotropin theory, theca cells make androgens under LH stimulation, which granulosa cells convert to ____ under FSH stimulation.
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estrogen- What enzyme converts androgens to estrogens in granulosa cells?
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Aromatase- What is the function of inhibin B secreted by granulosa cells?
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It selectively inhibits FSH secretion- Which four hormones share a common alpha subunit?
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LH, FSH, TSH, and hCG
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