Medicine: Blood Pressure: 10¢

To a physician a person's blood pressure is only one of several physiological facts needed for making an intelligent diagnosis. The physician measures the blood pressure by wrapping around the patient's upper arm a hollow rubber cuff to which is connected a graduated column of mercury. Applying a stethoscope over an artery in the forearm, the doctor pumps air into the hollow cuff until it stops circulation. At this instant the air pressure in the cuff equals the maximum (systolic) blood pressure in the arteries of the arm, and the doctor hears...

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