An older client has been diagnosed with chronic venous insufficiency. To promote venous return, the nurse encourages the client to take which action?

Correct Answer: A

Rationale: Sitting at the side of the bed for 15 minutes before standing promotes venous return in chronic venous insufficiency (CVI) by allowing gradual adjustment to upright posture, reducing venous pooling. CVI impairs vein valves, causing blood to stagnate in the legs. This technique, part of dependent positioning, helps the circulatory system adapt, minimizing edema and discomfort. While leg elevation is ideal, it wasn't an option; socks/shoes aid skin protection but not return directly, and warm compresses could worsen dilation, making sitting the best choice.

Correct Answer: B

Rationale: Prostaglandin F (PGF) causes renal vasoconstriction, reducing renal blood flow (RBF) and glomerular filtration rate (GFR). This contrasts with prostaglandins D, I, and E, which vasodilate. By constricting afferent and efferent arterioles, PGF decreases the pressure driving filtration, serving as a regulatory mechanism under certain conditions like inflammation. It does not directly affect sodium or water reabsorption, making B the correct function.

Correct Answer: B

Rationale: Principal cells are found in the collecting tubules (or ducts), where they regulate water and sodium balance via ADH and aldosterone. ‘Connecting tubules' likely refers to the collecting system in this context. Intercalated discs are cardiac structures, macula densa is in the distal tubule, and juxtaglomerular cells are in arterioles, making B the correct answer.

Correct Answer: C

Rationale: Peptides in the proximal convoluted tubule are reabsorbed via endocytosis. Filtered peptides are taken up by apical microvilli into tubular cells, where they're broken down into amino acids and released into the blood. This receptor-mediated process differs from facilitated diffusion (glucose), active transport (Na⁺), or passive diffusion (urea), making C correct.

Correct Answer: C

Rationale: Increased alveolar ventilation expels more CO₂, reducing blood PCO₂. Per the Henderson-Hasselbalch equation (pH = 6.1 + log([HCO₃⁻]/[0.03 × PCO₂])), lower PCO₂ increases pH (respiratory alkalosis) and decreases extracellular H⁺ concentration, as H⁺ binds with HCO₃⁻. Options A, B, and D misalign with this, making C correct.