What does a Net Filtration Pressure of -10 mmHg indicate?

Correct Answer: C

Rationale: A -10 mmHg NFP means no filtration forces opposing (oncotic + capsular, 40 mmHg) exceed driving force (hydrostatic, 30 mmHg), halting GFR (e.g., shock). Normal filtration needs positive NFP (~10 mmHg). Increased filtration requires higher positive e.g., hypertension. High reabsorption is tubular not glomerular. Lack of filtration distinguishes it, critical for acute renal failure risk, unlike normal or enhanced filtration.

Correct Answer: C

Rationale: Capsular space isn't part of the filtration membrane it's the filtrate receptacle (Bowman's space). Fenestrated endothelium, visceral membrane (podocytes), and filtration slits (with basement membrane) form the barrier plasma filters through. Space as destination distinguishes it, critical for filtration anatomy, unlike structural components.

Correct Answer: A

Rationale: Glomerular hydrostatic pressure (~55 mmHg) pushes fluid out drives filtration (e.g., Starling force). Back into vessels is oncotic/capsular opposes. No effect ignores its role false. Varying with oncotic misaligns independent. Outward push distinguishes it, critical for GFR, unlike opposing or neutral errors.

Correct Answer: A

Rationale: The proximal tubule is the primary site for organic ion secretion e.g., urate, creatinine via transporters (e.g., OATs). Loop of Henle concentrates minimal secretion. Distal tubule secretes H /K less organic. Collecting duct adjusts not primary. Proximal dominance distinguishes it, key to waste excretion, unlike later segments.

Correct Answer: B

Rationale: Proximal tubule reabsorption is isosmotic water follows Na (e.g., ~65% reclaimed), maintaining osmolarity. Leaky epithelium is permeable false. Na uses transcellular/paracellular not only transcellular. Chloride rises in lumen drives later reabsorption. Isosmotic nature distinguishes it, key to bulk reabsorption, unlike permeability or ion errors.