Diastolic blood pressure refers to the pressure in the arteries during which part of the cardiac cycle?

• A. Contraction
• B. Relaxation
• C. When heart rate is highest
• D. When arteries are blocked

Answer: (B)

Diastolic pressure is the pressure in the arteries when the heart is relaxed between beats. This relaxation phase, called diastole, is when the heart fills with blood and the arterial pressure falls to its lowest point in the cycle. That’s why diastolic pressure represents the minimum arterial pressure during a heartbeat.

The alternative ideas don’t fit as well: contraction corresponds to systolic pressure, the peak pressure when the heart pumps; heart rate being highest isn’t a specific phase of the cardiac cycle; and arteries being blocked describes a condition, not a normal phase of the cycle.