What defines blood pressure?

Blood pressure is defined as the pressure exerted by circulating blood upon the walls of blood vessels. This definition encompasses how blood flows through arteries, veins, and capillaries, and how the force of this flow impacts the structure of those vessels. Blood pressure is typically measured in millimeters of mercury (mmHg) and is represented by two values: systolic pressure, which occurs when the heart contracts and pumps blood, and diastolic pressure, which occurs when the heart is at rest between beats.

Understanding blood pressure is crucial for assessing cardiovascular health. Elevated blood pressure, or hypertension, can lead to adverse health outcomes such as heart disease and stroke.

The other choices do not accurately define blood pressure. The first choice incorrectly focuses on the heart rather than the blood vessels. The third choice refers to blood volume within the heart, which relates to different physiological measurements, such as preload, but does not define blood pressure itself. The fourth option discusses blood circulation rate, which is more related to cardiac output and blood flow dynamics rather than the concept of blood pressure.