The primary function of the descending loop of Henle in the kidney is?

Correct Answer: B

Rationale: Descending loop reabsorbs water osmotically not Na+, H+, or K+ (ascending/DCT). This specifies concentrating role, critical for gradient, contrasting with ion processes.

Correct Answer: D

Rationale: Efferent arteriole's narrowness raises glomerular pressure not Bowman's size/shape or afferent narrowness. This explains filtration pressure, key for GFR, contrasting with structural myths.

Correct Answer: B

Rationale: Podocytes are in the visceral layer of the glomerular capsule modified, branching epithelial cells forming filtration slits (e.g., pedicels) around capillaries. The proximal tubule has cuboidal cells reabsorption, not filtration. The distal tubule includes macula densa sensing, not epithelial. The collecting duct has principal/intercalated cells regulation, not filtration. Podocytes' location and structure distinguish them, key to glomerular filtration barrier, unlike tubular or regulatory cells.

Correct Answer: B

Rationale: Prostaglandins D/I/E cause renal vasodilation increase RBF and GFR (e.g., counter sympathetic tone). Vasoconstriction (e.g., PGF) decreases GFR opposite. Sodium reabsorption is tubular not vascular. Capsular pressure isn't prostaglandin-linked. Vasodilation's GFR boost distinguishes it, key to maintaining filtration, unlike constriction or tubular effects.

Correct Answer: A

Rationale: Bladder distension from increased intravesical pressure (filling) produces reflex contraction and sphincter relaxation micturition reflex (e.g., parasympathetic). Decreased pressure retains opposite. Osmolarity affects tubules not bladder. Low volume contracts sphincters delays voiding. Reflex response distinguishes it, key to micturition, unlike retention or tubular errors.