Pulse pressure and mean arterial pressure definitions:

• A. Pulse pressure = systolic − diastolic; MAP ≈ diastolic + 1/3 pulse pressure; both depend on stroke volume and arterial compliance.
• B. Pulse pressure = diastolic − systolic; MAP ≈ systolic + 1/2 pulse pressure; both depend on heart rate.
• C. Pulse pressure = systolic + diastolic; MAP equals average of systolic and diastolic; neither depends on compliance.
• D. Pulse pressure is unrelated to arterial pressures; MAP equals diastolic pressure.

Answer: (A)

Pulse pressure is the difference between systolic and diastolic pressures, and it captures how much pressure the heart generates with each beat. Mean arterial pressure is the average pressure in the arteries over the cardiac cycle and is best approximated by diastolic pressure plus about one third of the pulse pressure (equivalently, SBP + 2×DBP divided by 3). This weighting comes from the fact that the heart spends more time in diastole, so MAP sits closer to diastolic pressure.

These definitions also reflect physiology: pulse pressure grows when stroke volume is large or arterial walls are less compliant, because the systolic peak rises while diastolic pressure may fall with stiffer arteries. MAP changes with the overall flow and resistance of the systemic circulation, and is influenced by cardiac output and vascular tone as well as arterial compliance.

The other statements don’t fit because pulse pressure isn’t diastolic minus systolic, and MAP isn’t simply the arithmetic average of systolic and diastolic. The idea that neither pressure depends on arterial compliance ignores how stiffness of the arteries and the distance the pressure wave travels shape both pulse pressure and MAP.