Flashcards in Endocrine random facts Deck (58)
What can you use to treat HIV associated lipodystrophy?
Tesamorelin (a GHRH analog)
What are epinephrine's effects on the pancreas?
Stimulates both beta-2 and alpha-2, but alpha-2 inhibitory effect predominates so overall inhibitory effect. Pretreatment with an alpha-2 blocker would cause epinephrine's effect on beta-2 to be predominant and increase insulin secretion
How are prolactin and the thyroid hormones related?
TRH increases prolactin secretion (eg. in primary or secondary hypothyroidism)
What is the other name for IGF-1?
What is the effect of growth hormone on blood sugar?
GH increases insulin resistance (diabetogenic)
What do ghrelin and leptin do?
Ghrelin stimulates hunger and GH release and is produced by the stomach. Leptin is the satiety hormone produced by adipose tissue. Sleep deprivation leads to decreased leptin production
What regulates ADH?
Osmoreceptors in hypothalamus (primary), hypovolemia (secondary)
How does cortisol increase blood pressure?
1. Upregulates alpha-1 receptors on arterioles leading to increased sensitivity to norepinephrine and epinephrine, 2. At high concentrations, can bind to mineralocorticoid receptors
Why does excess cortisol give you striae?
Decreases fibroblast activity
Relationship between pH and calcium homeostasis
Increase in pH causes an increased affinity of albumin to bind to calcium which causes hypocalcemia (cramps, pain, paresthesias, carpopedal spasm)
What type of cells secrete PTH?
Chief cells of the parathyroid
Where in the kidney does PTH cause the excretion of Ca and PO4?
Ca in the DCT, PO4 in the PCT
Where is calcitonin from?
Parafollicular cells of the thyroid
Which hormones act through cAMP?
FSH, LH, ACTH, TSH, CRH, hCG, ADH (V2 receptor), MSH, PTH, calcitonin, GHRH, glucagon
FLAT ChAMP (plus a few more)
Which hormones act through cGMP?
ANP, BNP, NO (EDRF)
Which hormones act through IP3?
GnRH, Oxytocin, ADH (V1 receptor), TRH, Histamine (H1 receptor), Angiotenin II, Gastrin
Which hormones act through an intracellular receptor?
Vitamin D, Estrogen, Testosterone, T3/T4, Cortisol, Aldosterone, Progesterone
Which hormones act through an intrinsic tyrosine kinase?
Insulin, IGF-1, FGF, PDGF, EF
MAP kinase pathway
Which hormones act through a receptor-associated tyrosine kinase?
Prolactin, Immunomodulators (eg, cytokines IL-2, IL-6, IFN), GH, G-CSF, Erythropoietin, Thrombopoietin,
What converts T4 to T3
What is the enzyme responsible for oxidation and organification of iodide as well as coupling of monoiodotyrosine (MIT) and di-iodotyrosine (DIT)?
Peroxidase (propylthiouracil inhibits both peroxidase and 5'deiodinase. Methiazole inhibits peroxidase only)
What is the Wolff-Chiakoff effect?
Excess iodine temporarily inhibits thyroid peroxidase leading to decreased iodine organification and decreased T3/T4 production
What should you think of if you see Homer-Wright pseudo rosettes?
Presentation of neuroblastoma?
Irregular mass crossing the midline OR opsoclonus-myoclonus syndrome ("dancing eyes-dancing feet"). HVA and VMA increased in the urine. Bombazine and neuron-specific annuals positive
What mutation is neuroblastoma associated with?
Overexpression of N-myc oncogene
Treatment for pheo?
Alpha blockers THEN beta blockers THEN surgical resection
Histologic findings in Hashimoto's
Hurthle cells, lymphoid aggregate with germinal centers
Empty-appearing nuclei with central clearing, nuclear grooves
Papillary thyroid carcinoma, increased risk with RET and BRAF mutations, childhood irradiation, excellent prognosis
Cancer invading the thyroid capsule
Follicular carcinoma, good prognosis