New York State Basic Emergency Medical Technician (EMT-B) Practice Exam

What is the correct statement about diastolic blood pressure?

1. Exists when heart left ventricle is refilling

2. Due to the contraction of the ventricles of the heart

3. Caused by contraction of the atria of the heart

4. Caused by relaxation of the walls of the major arteries

The correct answer is: Caused by relaxation of the walls of the major arteries

Diastolic blood pressure refers to the pressure in the arteries when the heart is at rest, specifically during the filling phase of the heart's ventricles. This occurs after the ventricles contract and push blood into the arteries, creating systolic pressure. During diastole, the heart muscle relaxes, allowing the chambers to fill with blood. The correct statement about diastolic blood pressure relates to the period when the heart's ventricles are refilling with blood. During this phase, the major arteries are not under the direct pressure effects of ventricular contraction but are instead experiencing a pressure that is maintained by the elastic recoil of the arterial walls after the heart has pumped. This allows for a continuous flow of blood even when the heart is not actively contracting. The incorrect options misattribute the nature of diastolic blood pressure to different cardiac activities or conditions. The contraction of the ventricles directly relates to systolic blood pressure; the contraction of the atria has minimal impact on overall blood pressure measurement, as it primarily assists in filling the ventricles; and while relaxation of arterial walls influences blood flow, it is primarily the stable pressure from the arterial system during diastole that defines diastolic pressure.