Pressure

Sphygmomanometer is an instrument for measuring blood pressure in the arteries. It consists of an inflatable cuff connected via a rubber tube to a column of mercury with a graduated scale. The cuff is applied to a limb (usually the arm) and inflated to exert pressure on a large artery until the blood flow stops. The pressure is then slowly released and, with the aid of a stethoscope to listen to the pulse, it is possible to determine both the systolic and diastolic pressures (which can be read on the scale).