endocrine - Memory Flashcards
venous drainage of adrenals
Similar to testicles; L into L renal vein, R directly into IVC
similarities in the alpha subunit of pituitary hormones
FSH, LH, hCG, and TSH
delta cells release
somatostatin; can have somatostatinoma with hyper/hypoglycemia, gallstones, steatorrhea, etc.
positive regluators of insulin
GH and hyperglycemia; beta agonists
Negative regulators of insulin
somatostatin, hypoglycemia and cortisol; alpha-2 agonists inhibit insulin
Prolactin
promotes milk production; inhibits GnRH; Negative feedback by stimulating dopamine
GH regulators
somatostatin and glucose inhibit; exercise and sleep increase it
GH function
increases Linear bone growth through somatomedin and muscle mass. Increases Insulin resistance
Rate limiting enzyme in Adrenal steroid synthesis
Desmolase; inhibited by antifungal drug ketoconazole; activated by ACTH
Cortisol mechanism for anti-inflammation
inhibits PL-A2 and COX-2, decreases neutrophil adhesion (will see neutrophilia), blocks histamine release, reduces eosinophils, Blocks IL-2 production
Cortisol function
upregulates alpha-1 receptors for blood pressure, increases insulin resistance, increases gluconeogenesis
Metyrapone
inhibits 11-beta hydroxylase; increases ACTH surge because a decrease in cortisol. The 17-hydroxy corticosteroid will be produced and can be found in urine
Hashimoto Thyroiditis pathogenesis
antimicrosomal antithyroglobulin antibodies, HLA-DR5, increased risk of non-hodgkin’s lymphoma
Hashimoto histology
Hurthle cells, lymphocytic infiltrate with germinal centers
Hashimoto presentation
hypothyroid (can be hyper early), PAINLESS, high antiperoxidase tighters
Cretinism presentation
Pot bellied, pale, puffy-faced child with protruding umbilicus and protuberant
Subacute Thyroiditis (de Quervain’s)
follows flu-like illness, HLA-B35. Histo: granulomatous mixed cellular (vs. hashimoto), no antiperoxidase (vs. hashimoto)
Subacute thyrotoxicosis (granulomatous thyroiditis)
painful goiter, thyrotoxicosis followed by hypothyroidism.
Riedel’s thyroiditis
thyroid is replaced by fibrous tissue “hard as rock”. Painless, Anti thyroid peroxidase. Macrophages and eosinophils (vs. hashimoto)
toxic multinodular goiter
follicles are distended with colloid and lined by flattened epithelium with areas of fibrosis and hemorrhages. The focal patches of hyperfunctioning follicular cells are working independently of TSH due to mutation in TSH receptor.
Papillary carcinoma
Radiation, psammoma, orphan annie, RET BRAF
Follicular Carcinoma
Hematogenous spread, invades capsule, hurthle cells, RAS
Medullary carcinoma
Parafollicular cells. Amyloid calcitonin, MEN 2A 2B, RET
Struma Ovarii
Thyroid releasing teratoma
Hyper PTH clinical
Bones, Moans, Grones, and stones; Osteitis fibrosa cystica - cystic bone spaces filled with borwn fibrous tissue.. Bones of pelvic girdle, pectoral girdle, and limbs, subperiosteal thinning, salt an pepper appearance of skin. Increased calcium stimulates gastrin secretion -> peptic ulcers
secondary hyper PTH
presents with hypocalcemia and is due to renal failure mostly, with increased levels of phosphorous and decreased calcium. The bone lesions in secondary are Renal osteodystrophy
Causes of secondary hyperthyroid
Testicular cancer or neoplasm releasing hCG which shares alpha subunit with TSH and can increase thyroid
how does alkalosis cause functional hypocalcemia
More negative charge to albumin so more binding of free calcium which can lead to tetany but total body calcium levels remain same.
Treatment for Nephrogenic DI
hydrochlorothiazide (paradoxical antidiuretic effect), Indomethacin (prostaglandins inhibit ADH so inhibit prostaglandin synthesis), amiloride
Treatment for SIADH
Demeclocycline and H2O restriction
SIADH sodium and volume status
euvolemic hyponatremia; initial increase in volume inhibits renin and reduces aldosterone to deplete excess volume and therefore euvolemia and hyponatremia
SIADH causes
Ectopic (small cell lung cancer), Lung diseases, CNS disorder, Drugs (cyclophosphamide)
Causes of hypopituitarism
Sheehan syndrome (hemorrhagic infarct postpartum bleeding; presents w failure to lactate), craniopharyngioma (Rathke’s pouch), empty sella syndrome, pituitary apoplexy (acute bleeding into preexisting adenoma, acute depletion of ACTH and cortisol can lead to cardiovascular collapse)
