What is the difference between systolic and diastolic blood pressure?

Systolic and diastolic blood pressures are key components of the cardiovascular system's function. Systolic blood pressure is the measurement taken when the heart contracts, pushing blood into the arteries, representing the pressure in the arteries at this moment of peak force. Conversely, diastolic blood pressure reflects the pressure in the arteries when the heart is in between beats, or in a resting phase, allowing the chambers to refill with blood. Understanding these definitions clarifies why the distinction is crucial for assessing cardiovascular health.

The choice that states systolic is during heartbeats and diastolic is resting pressure accurately captures the physiological processes involved. It emphasizes the dynamic nature of blood pressure changes in relation to the cardiac cycle, where systolic pressure is always higher than diastolic pressure because of the active force exerted by the heart compared to its resting state.

Other options do not correctly define these pressures. One suggests that systolic is associated with resting pressure, which misrepresents the active role of systolic pressure during heart contractions. Another option incorrectly states that both refer to relaxing heart pressure, which conflates two distinct and critical phases of the cardiac cycle. Finally, claiming that diastolic pressure is higher than systolic pressure contradicts fundamental hemod