Stroke volume is the volume of blood:

Correct Answer: C

Rationale: Stroke volume is the amount of blood ejected by a ventricle during a single contraction.

Correct Answer: B

Rationale: The descending aorta (abdominal aorta) ends by branching into the common iliac arteries.

Correct Answer: A

Rationale: The valves of the heart are made up of dense connective tissue, which provides the necessary strength and flexibility to withstand the pressure changes within the heart during the cardiac cycle.

Correct Answer: D

Rationale: The P wave on an ECG signifies atrial depolarization, initiating atrial contraction and subsequent ventricular filling.

Correct Answer: A

Rationale: Systemic circulation delivers blood to all body parts except the lungs, which are part of pulmonary circulation.