DaVita Patient Care Technician (PCT) Practice Exam

The sphygmomanometer is the instrument specifically designed for measuring blood pressure. It typically consists of an inflatable cuff that is placed around the patient's arm, and a scale to read the pressure in millimeters of mercury (mmHg). When the cuff is inflated, it compresses the artery, and as the pressure is released, the blood flow resumes, which can be detected by listening to the sounds of the blood flow using a stethoscope or by observing the oscillations on the sphygmomanometer.

In contrast, a thermometer measures body temperature, a stethoscope is used to listen to internal body sounds (such as heartbeats and lung sounds), and a spirometer measures the volume of air inhaled and exhaled by the lungs. Each of these instruments serves a distinct purpose in medical assessments, but the sphygmomanometer is uniquely suited for determining blood pressure.