Question

What is meant by blood pressure? How does systolic pressure differ from diastolic pressure?

Answer 1

The pressure of circulating blood against the walls of blood vessels is known as blood pressure or BP. The heart pumping blood through the circulatory system results in most of the pressure formed. The blood pressure is usually expressed in terms of systolic pressure over diastolic pressure in the cardiac cycle. It is measured in terms of millimeters of mercury or mmHg, above the surrounding atmospheric pressure.

Complete answer:
Pressure of blood within the arteries can be termed as the blood pressure. Blood pressure is primarily produced by contraction of heart muscle. The measurement of blood pressure is recorded by two numbers; the first is the systolic pressure, which is measured after the heart contracts and is highest. The second is the diastolic pressure, which is measured before the heart contracts and lowest. To measure the pressure, a blood pressure cuff is used. Hypertension is the elevation of blood pressure.
When the heart is beating actively, blood is ejected out into the arteries, known as systole. The pressure within arteries rises due to the dynamic ejection of blood into the arteries. Systolic blood pressure is the peak blood pressure reached during an active cardiac contraction. For a normal person sitting quietly, the systolic blood pressure is $120{\text{ }}mmHg$ or below.
The pressure that blood exerts within the arteries in between heartbeats is known as diastolic blood pressure, which is, when the heart is not actively ejecting blood into arteries. The cardiac ventricles relax momentarily after the heart is finished contracting, so that it can be refilled with blood, for the preparation of the next contraction. This period of ventricular relaxation is called diastole and the blood pressure during diastole is known as diastolic blood pressure. The diastolic blood pressure of a normal person during quiet rest is about $80{\text{ }}mmHg$ or below $1$. The diastolic blood pressure is often increased during quiet rest in hypertension.

Note:
The systolic and diastolic blood pressure, which is the highest and the lowest blood pressure reached during any given cardiac cycle, can change substantially from minute to minute depending upon the state of activity, state of stress, state of hydration, and several other factors of a person. The pressures within the blood vessels during different parts of the cardiac cycle are represented by systolic and diastolic blood pressure.