Pathoma - 15 (Endocrine)

arold001's version from 2015-12-27 18:25

Section 1

Question Answer
Why does a prolactinoma produce amenorrhea?prolactin inhibits GnRH --> decrease LH/FSH --> decrease estrogen
Why do pts with acromegaly also develop secondary diabetes?GH induces liver gluconeogenesis
how are GH and IGF-1 related in pts with acromegaly?GH goes to the liver and causes increase production of IGF-1 --> its actually IGF that mediates the growth of tissues
post-partum pt presents with poor lactation, LOSS OF PUBIC HAIRsheehans syndrome
why do pts with Sheehans syndrome hypopituarism) show loss of pubic hair?pubic hair is dependent on LH and androgens for growth
what causes empty sella syndrome?herniation of arachnoid and CSF into sella compresses and destroys the pituitary
whats the tx for central diabetes inspidus?desmopressin = ADH analog
name 2 drugs whose side effect causes nephrogenic diabetes inspidus?lithium and demeclocycline
whats the most common cause of SIADH?small cell lung carcinoma
what drug can cause SIADH?carbamazepine and cyclophosphamide (alkylating agent)
whats the tx of SIADH?water restriction and demeclocycline

Section 2

Question Answer
base of tongue mass?lingual thryoid
why do pts with hyperthyroidism show increased BMR?increased synthesis of Na+/K+ ATPase
why do pts with hyperthyroidism show increased sympathetic nervous system?increase expression of beta-1 receptors
hyperthryoidism or hypothyroidim: hypocholesterolemia and hyperglycemia?hyperthyroidism
why do you see hyperglycemia in pts with HYPERthyroidism?thyroid hormone stimulates gluconeogenesis and glycogenolysis --> hyperglycemia
most common cause of hyperthyroidism?graves disease = autoantibody IgG that stimulates TSH receptor
why do pts with graves disease present with diffuse goiter?constant TSH stimulation leads to thyroid hyperplasia and hypertrophy
what makes up glycosaminoglycan?chrondroitin sulfate and hyaluronic acid
histology shows SCALLOPED COLLOIDGraves disease
whats the MOA of thyroid medication "thioamide"?blocks peroxidase
name 3 different ways to treat graves disease? (3 drugs)beta blockers, thioamide, radioiodine ablation
what causes multinodular goiter?iodine deficiency
infant presents with mental retardation, short stature, coarse facial features, enlarged tongue and UMBILICAL HERNIAcretinism = hypothyroidism
whats a HY cause of cretinism?dyshormonogenetic goiter = thyroid peroxidase deficiency --> defect in thyroid hormone production
what is myxedema?hypothyroidism in adults
what is myxedema present as?accumulation of glycosaminoglycans in skin and soft tissue -> deepening of voice and enlarged tongue
hyperthryoidism or hypothyroidim: hypercholesterolemia?hypothyroidism
what are the 2 most common causes of myxedema (hypothyroidism)?iodine deficiency and hashitmotos thyroiditis
what condition is characterized by autoimmune destruction of the thyroid gland?hashimotos thyroiditis
HLA-DR5hashimotos thyroiditis
what HLA is a/w hashimotos?HLA-DR5
antithyroglobulin and antimicrosomal Abhashimotos thyroiditis
what cancer is a/w hashimotos?B-cell marginal zone lymphoma
tender thyroid with transient hyperthyroidismsubacute granulomatous de quervain thyroiditis
hypothyroidism with hard as wood nontender thyroidreidel fibrosing thyroiditis

Section 3

Question Answer
increased I-131 radioactive uptake (HOT nodule) are seen in what 2 conditionsgraves disease or nodular goiter
decreased I-131 radioactive uptake (COLD nodule) are seen in what 2 conditionsadenoma and carcinoma = need biopsy!!
name the 4 types of thyroid carcinomas?papillary, follicular, medullary, anaplastic thyroid carcioma
whats the most common type of thyroid carcinoma?papillary carcinoma
ionizing radiation is a major risk factor for which thyroid carcinoma?papillary carcinoma
orphane annie eye and nuclear groves, psammoma bodiespapillary carcinoma
malignant proliferation of parafollicular C cells (cells adj to follicle cells)medullary carcinoma of thyroid
whcih cells secrete calcitonin?parafollicular C cells of the thyroid
biopsy shows sheets of malignant cells in an amyloid stroma...diagnosis? and whats the amyloid made of?medullary carcinoma of the thyroid. calcitonin myloid
MEN2A?medullary carcinoma of thyroid
parathyroid adenomas
MEN2Bmedullary carcinoma of thyroid
oral neuromas
what procedure should be done if you find RET mutation?thyroidectomy!

Section 4

Question Answer
which cells secrete PTH?chief cells of the parathyroid
how does PTH regulate bone resorption?PTH activates osteoblast, which activates osteoclast --> resorb bone
whats the most common cause of PRIMARY hyperparathyroidism?parathyroid adenoma
whats is nephrocalcinosis?deposition of calcium in renal tubules --> sign of primary hyperparathyroidism
whats a HY complication of primary hyperparathyroidism?acute pancreatits! think of Ca+2 as enzyme activator
why do you see increase ALKP in primary hyperparathyroidism?PTH activates osteoblasts which produces alkaline phosphate needed to lay down bone
what pathway does PTH go thru? (JAK-STAT, cAMP, TK?)Gs --> AC --> increased cAMP
whats the most common cause of secondary hyperparathyroidism?chronic renal failure --> increase phosphate levels binds to and lowers calcium levels which increases PTH
what the cause of pseudohypoparathyroidism?end-organ resistance to PTH a/w defect in Gs protein!
pt presents with signs of hypocalcemia, short stature and short 4th/5th digitspseudohypoparathyroidism

Section 5

Question Answer
where are beta cells located in the islet?center!
what glucose transport is located in skeletal muscles and adipose tissue?GLUT4
what hypersensitivity reaction in DM1?Type IV HSN
what causes DM1?autoimmune destruction of beta-cells by T-LYMPHOCYTES!
What HLA is associated with DM1? Hashimotos?DM1: HLA-DR3 and HLA-DR4
Hashimotos: HLA-DR5
What complication is associated with DM1?DKA = diabetic ketoacidosis
what 3 processes does glucagon upregulate to increase glucose?glycogenolysis, gluconeogeneis, lipolysis
whats the pathogenesis of DKA?arises with stress --> Epi stimulates glucagon secretion increases lipolysis (along with gluconeogenesis ad glycogenolysis) --> increased lipolysis leads to FFA --> liver converts FFA to KETONES!
what causes DM2?end organ insulin RESISTANCE
why does obesity lead to DM2?obesity leads to decreased NUMBER of insulin receptors on skeletal and adipose tissue
which diabetes is associated with genetics?DM2
histology shows amyloid deposition in islets...which diabetes?DM2
which diabetes is a/w hyperosmolar non-ketotic coma?DM2
whats the leading cause of death in diabetics?cardiovascular disease due to NEG of vessels leading to atherosclerosis
diabetic hyaline arteriosclerosis prefers which renal arteriole?EFFERENT arteriole
which enzyme converts glucose to sorbitol?aldose reductase
what causes treatment-resistant peptic ulcers?gastrinoma = zollinger ellison syndrome (pancreatic neoplasm)
cause of watery diarrhea, hypokalemia, achorhydria?VIPomas (VIP inhibits gastric acid secretion)
pt presents with achlorhydria (due to inhibition of gastrin) and cholithiasis with steatorrhea (due to inhibition of CCK)somatostatinoma

Section 6

Question Answer
Why do you see muscle weakness in pts with cushing syndrome?cortisol breaks down muscle for gluconeogenesis
pt with hypercortisolism with BL adrenal atrophy...diagnosis?exogenous cortisol use
pt with hypercortisolism with atrophy of uninvolved adrenal gland...diagnosisprimary adrenal adenoma, hyperplasia or carcinoma
pt with hypercortisolism with BL adrenal hyperplasia...which 2 conditions?ACTH-secreting pituitary adenoma and paraneoplastic ACTH secretion (small cell lung carcinoma)
What is conns syndrome?hyperaldosteronism
difference btw primary and secondary hyperaldosteronismprimary hyperaldosteronism: LOW renin (high blood pressure goes thru kidney and downregulates renin secretion).
secondary hyperparathyroidism: HIGH renin
what is waterhouse-fridrichsem syndrome?adrenal insufficiency due to hemorrhagic necrosis of the adrenal glands due to DIC (neisseria)
what is addisons disease?chronic adrenal insufficiency due to desruction of adrenal gland
name 3 common causes of addisons disease?autoimmune destruction of adrenal gland, TB, metastatic carcinoma from lung
pt presents with hypotension, hyponatremia and hypovolemic, HYPERPIGMENTATION (due to increased ACTH) after TB infectionaddisons disease = chronic adrenal insufficiency (not making aldosterone, cortisol or sex steroids)
where does lung cancer love to spread to?ADRENAL GLANDS!! can cause adrenal insufficiency
why do we see hyperpigmentation in pts with adrenal insufficiency?low cortisol --> INCREASE ACTH production --> increase MSH!
Where is the adrenal medulla derived from?neural-crest derived chromaffin cells
brown tumor of adrenal medullapheochromocytoma
urine shows increase metanephrines and vanillylmandelic acidpheochromocytoma
what are the rules of 10 for pheochromocytoma?10% bilateral, familial, malignant, located outside adrenal medulla (bladder)
associated with MEN2A, MEN2B, VHL, NF-1pheochromocytoma

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