Peripheral vascular resistance can be best gauged by

Correct Answer: C

Rationale: Peripheral vascular resistance (PVR) is best reflected by diastolic blood pressure, as it represents the baseline pressure maintained by arteriolar tone when the heart isn’t pumping. Pulse pressure reflects arterial elasticity, mean arterial pressure balances systole/diastole, and systolic pressure peaks with ventricular contraction, not resistance.

Correct Answer: B

Rationale: The visceral serous pericardium is the inner layer of the pericardial sac, adhering to the heart’s surface, and is synonymous with the epicardium (B). The endocardium (A) lines the heart chambers, fibrous pericardium (C) is the outer tough layer, and myocardium (D) is the muscular layer.

Correct Answer: B

Rationale: The heart wall (myocardium) is supplied oxygenated blood by coronary arteries (B) branching from the aorta. Blood in chambers (A) doesn’t nourish the wall, cardiac veins (C) drain it, and pulmonary arteries (D) supply lungs.

Correct Answer: C

Rationale: Systole (C) is heart muscle contraction (atrial or ventricular). Diastole (A) is relaxation, peristalsis (B) is GI movement, and spasm (D) is involuntary contraction.

Correct Answer: D

Rationale: Capillaries (D) are thin-walled, allowing gas, nutrient, and waste exchange between blood and tissues. Arteries (A), arterioles (B), and venules (C) transport, not exchange.