Answer
Pressure is force per unit area
Blood pressure is the force exerted on blood vessel wall by the blood within them
A blood pressure of 120 mmHg , means that that pressure would support a column of mercury 120 mm tall in a mercury barometer at sea level
Work Step by Step
Systolic pressure is practically the pressure exerted on the walls of a large blood vessel near the heart when the left ventricle contracts. The compliance of the large elastic vessel allows it to expand and to pass the pressure down the system of blood vessels Normal systolic value is usually quoted as 12o mmHg for healthy adults
Diastolic pressure. Then the ventricles relax and te aortic valve closes the large elastic artery recoils a d drops to its lowest pressure --enough to keep the blood moving. This is the diastolic pressure usually given a normal range of 70 to 80 mm Hg in an adult
