Caption: Sphygmomanometer
Text: A sphygmomanometer is a device used to measure blood pressure. It consists of an inflatable cuff with an attached manometer for measuring pressure in the cuff. The cuff is placed around the upper arm and pumped up to a pressure that exceeds arterial pressure, so that arterial inflow to the arm is stopped. As the blood pressure cuff is slowly deflated, the person taking the reading uses a stethoscope to listen to sounds transmiitted through the brachial artery at the elbow. As pressure in the cuff falls below systolic blood pressure, blood begins to flow in the brachial artery causeing distinct sounds of pulsation that can be heard in the stethoscope. With continued deflation, the sounds disppear when diastolic pressure is reached. The operator simply watches the gauge on the manometer and takes note of the pressure when the sounds appear and then disappear, denoting systolic and diastolic blood pressure.