NBME 22 Flashcards
explain all the problems that can happen with the posterior cord of the brachial plexus or parts of it
axillary –> deltoid paralysis
radial –> saturday night palsy, wrist drop
posterior –> wrist drop
how does the clostridium perfringens alpha toxin work
lecithinase –> splits lecithin into phosphorylcholine and diglyceride
what do prostaglandins do to the kidney
prostaglandins cause vasodilation of the afferent arteriole
-NSAIDs then cause vasoconstriction
what does angiotensin 2 do to the kindey
vasoconstriction of the efferent arteriole
-ACEi cause vasodilation of the efferent arteriole
what are the H2 blockers and how do they work
H2 blockers –> cimetidine, ranitidine, famotidine, nizatidine
-work by blocking the H2 receptor which works via Gs and cAMP which then induces the H+/K+ ATPase to work
what type of medication is first line for benign prostatic hyperplasia and what type of receptor does it work on
prazosin, terazosin, doxazosin, tamsulosin
-alpha 1 blocker (works on post synaptic cells)
what is the life span of an erythrocyte
120 days
how does the small intestine look on x-ray
feathery due to the vili and greater mucosal surface area
what enzymes do fluorouracil and methotrexate work on respectively
FU (prodrug is capecitabine): thymidylate synthase
MTX: dihydrofolate reductase
patient has had previous chemo for hodgkins…. years later they have numerous blast forms seen in their blood. what do they have?
AML (you will see auer rods)
how do the potassium sparing diuretics work
work by blocking Na+ channel (ENaC)
-decrease the luminal permeability to Na+ in the cortical collecting duct
first vs second vs third degree burn
First –> superficial, through epidermis (common sunburn), painful, erythematous, blanching
Second –> partial-thickness burn through epidermis and dermis, skin is blistered and usually heals without scarring, painful, erythematous, blanching
Third –> full-thickness burn through epidermis, dermis, and hypodermis, skin scars with healing, painless, waxy, leathery appearance, nonblanching
what is osteitis deformans
another name for pagets disease of bone
what do laxatives do to the body
pt will have an increased anion gap metabolic acidosis and hypokalemia
pt has isolated thrombocytopenia… what do you think of?
immune thrombocytopenic purpura
where is the epileptic seizure if a pt smells burning rubber before the event
olfactory hallucination –> usually due to aura of TEMPORAL LOBE epilepsy and in brain tumors
what type of medication do you give to a pt with nephrogenic diabetes insipidus
hydrochlorothiazide
-note that if the nephrogenic DI is due to lithium then use amiloride for the pt
explain postpartum thyroiditis
self-limited thyroiditis arising up to 1 year after deliver. presents as transient hyperthyroidism, hypothyroidism, or hyper followed by hypothyroidism
- majority of women are euthyroid following resolution
- thyroid usually painless and normal in size
- histology –> lymphocytic infiltrate with occasional germinal center formation
what does an increase in dATP do
inhibits ribonucleotide reductase used in DNA synthesis
what effect does testosterone have on the kidney
it stimulates EPO and increases levels of hemoglobin
how does parvo cause anemia
interruption of erythrocyte precursors
how does nicotinic acid (niacin/vitamin B3) work
inhibits lipolysis (hormone sensitive lipase) in adipose tissue -reduces hepatic VLDL synthesis
In I-cell disease what happens to the stuff that can’t be taken to the lysosomes for degradation
it ends up being secreted from the cells into the extracellular space
egophony
increased resonance of voice sounds heard when auscultating the lungs, often caused by lung consolidation and fibrosis
-It is due to enhanced transmission of high-frequency sound across fluid, such as in abnormal lung tissue, with lower frequencies filtered out
normal pressure vs ex vacuo hydrocephalus
normal pressure –> affects the elderly and CSF pressure is only elevated episodically, expansion of ventricles distorts the fibers of the corona radiata –> triad of urinary incontinence, gait apraxia, and cognitive dysfunction (WET, WOBBLY, AND WACKY)
ex vacuo –> appearance of increased CSF on imaging but is actually due to decrease in brain tissue and neuronal atrophy. ICP is normal
undialyzed renal failure leads to what acid base disorder
metabolic acidosis
-as a result bicarb gets depleted as it tries to buffer the accumulation of organic acids
pt presents after spontaneous abortion with thrombosis and elevated PT and aPTT
antiphospholipid syndrome
- treat with systemic anticoagulation
- you can also expect to see anticardiolipin antibodies which can cause false-positive VDRL/RPR
- lupus anticoagulant can cause prolonged PTT that is not corrected by the addition of normal platelet-free plasma
pneumonics for sensitivity and specificity
SN-N-OUT –> sensitivity rules out
SP-P-IN –> specificity rules in
what equation do you use to determine the infusion rate of a drug (maintenance dose)
(CL x Css) / F
loading dose equation
(Css x Vd) / F
lateral corticospinal tracts
MOTOR (descending)
-voluntary movement of contralateral limbs
what are the ascending tracts in the spinal cord
dorsal column
-pressure, vibration, fine touch, proprioception
spinothalamic tract
- lateral –> pain, temp
- anterior –> crude touch, pressure
how does kaposi sarcoma look on histology
slit like vascular spaces with plump spindle shaped stromal cells
inheritance patterns of protein structural genes vs enzyme deficiencies
protein structural genes –> AD
enzyme deficiencies –> AR
when do babies develop a social smile and start cooing
2 months
when do babies lift their head while prone
1 month
side effect of nitrates
headache
-also hypotension and dizziness
