Identify the vessels that branch off the aortic arch.

Correct Answer: A

Rationale: The aortic arch branches into the brachiocephalic, left common carotid, and left subclavian arteries (A). B is descending aorta, C are veins, D is ascending aorta.

Correct Answer: C

Rationale: The kidneys receive ~25% (C) of cardiac output (~1.2 L/min of 5 L/min) for filtration. A, B are too low, D too high.

Correct Answer: D

Rationale: The T wave (D) represents ventricular repolarization. P wave (A) is atrial depolarization, QRS (B) is ventricular depolarization, and U wave (C) is minor/uncertain.

Correct Answer: C

Rationale: Resting cardiac output is ~5.25 L/min (C, 70 ml × 75 bpm). A and B are too low, D too high for rest.

Correct Answer: C

Rationale: S₂ (C) has a longer, sharper sound (~0.08 s) than S₁ (~0.07 s) due to semilunar valve closure. A is S₁, B is true but not unique, D is secondary.