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USMLE- Endocrine and physiology

rename
jamakumi's version from 2016-06-28 08:57

Section 1

Question Answer
What structure secretes prolactin?anterior pituitary
What is the function of prolactin?Stimulates milk production in breast, inhibits ovulation in females and spermatogenesis in males by inhibiting GnRH synthesis and release
What substance inhibits the secretion of prolactin from pituitary?dopamine from hypothalamus. Prolactin in turn inhibits its own secretion by increasing dopamine synthesis and secretion from hypothalamus
What substance stimulates the secretion of prolactin?TRH from hypothalamus
What class of drug is use to inhibit prolactin secretion and tx of prolactinoma?dopamine agonists (bromocriptine)
What is a prolactinoma?the most common type of pituitary tumor that is a PRL-secreting tumor
What drugs are use to stimulate prolactin secretion?dopamine antagonists (most antipsychotics) and estrogens (OCP, pregnancy)
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Section 2

Question Answer
What is the other name of growth hormone?somatotropin
What structure is responsible for the secretion of GH?anterior pituitary
What is the function of GH?stimulates linear growth and muscle mass through IGF-1/somatomedin secretion. increase insulin resistance (diabetogenic)
What substance stimulates the secretion of GH?GH is released in pulses in response to GHRH, secretion increase during exercise and sleep
What substances inhibit secretion of GH?glucose and somatostatin
Is it true to say that an excess secretion of GH (pituitary adenoma) may cause acromegaly (adults) or gigantism (children)?yes, it's true
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Section 3

Question Answer
What structure is responsible for the secretion of cortisol?adrenal zona fasciculata
What is the mnemonic for the function of cortisol?Cortisol is BBIIG: Blood pressure, Bone formation, Anti-Inflammatory, Insulin resistance, Gluconeogenesis
What is the function of cortisol on blood pressure?Maintains blood pressure (upregulates alpha1-receptors on arterioles->increase sensitivity to NE and Epinephrine
What is the function of cortisol on bone formation?cortisol decrease bone formation
What is the function of cortisol on Anti-inflammatory/Immunosuppressive?1)inhibits production of leukotrienes and prostagladins 2)inhibits leukocyte adhesion->neutrophilia 3)blocks histamine release from mast cells 4) reduces eosinophils 5)blocks IL-2 production
What is the function of cortisol on insulin resistance?cortisol increases insulin resistance (diabetogenic)
What is the function of cortisol on Gluconeogenesis?Cortisol increases gluconeogenesis, lipolysis and proteolysis, It's also inhibiting fibroblasts (causes striae)
What substances cause cortisol production in adrenal zona fascicula?CRH (hypothalamus) stimulates ACTH release (pituitary)
What is the impact if there is an excess of cortisol?diminution of CRH, ACTH and cortisol secretion
What is the impact of chronic stress on cortisol?chronic stress induces prolonged secretion
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