USMLE STEP 1 RENAL Questions and Answers with Complete Solutions 2024

USMLE STEP 1 RENAL Questions and Answers with Complete Solutions 2024 anatomy of bowmans capsule - ANSkidney and ureters are retroperitoneal ureters are BEHIND vas deferens, BEHNID uterine artery water distribution in body compartments - ANS... glomerular filtration barrier components - ANSFenestrated capillary endothelium (size barrier) Fused basement membrane with heparan sulfate (negative charge barrier) Epithelial layer consisting of podocyte foot processes THE BASEMENT MEMBRANE LAYER IS LOST IN NEPHROTIC SYNDROME - LOST CHARGE BARRIER --> albuminuria, hypoproteinemia, generalized edema, and hyperlipidemia BM = type IV collagen, made by visceral epithelial/podocyte renal clearance + GFR - ANSCL = UV/P in mL/min NL ~ 100 mL/min creatinine moderately overestimates GFR (some secretion) inulin accurately measures GFR in pregnancy and early diabetic nephropathy --> INCR in Cr CL in elderly and acute/chronic renal dz --> DECR in Cr CL effective renal plasma flow (ERPF) - ANSCL = UV/P use PAH as proxy ERPF can be estimated using PAH CLEARANCE bc it is both FILTERED and actively SECRETED (CARRIER MEDIATED TRANSPORT) in the proximal tubule + ALL PAH entering the kidney is EXCRETED --> typically underestimates renal plasma flow by 10% RBF = RPF/(1 - Hct) filtration fraction + load - ANSFF = GFR/RPF NL ~ 20% filtered load = GFR x plasma concentration modulators of afferent + efferent arteriole - ANS... effect of plasma protein concentrati