Which of the following parts of a sphygmomanometer Is used to read the systolic and diastolic values of a patient's blood pressure?

The cuff is a crucial component of the sphygmomanometer that wraps around the patient's arm and inflates to restrict blood flow. While it plays a vital role in the measurement process, it does not provide a direct reading of blood pressure values; rather, it facilitates the measurement taken by the pressure indicator.

The diaphragm in a sphygmomanometer is responsible for sensing the pressure changes within the cuff as it inflates and deflates. However, it does not display the blood pressure readings itself. Instead, it converts the pressure changes into a movement that can be measured by the pressure indicator.

The inflation bulb is used to manually inflate the cuff to create pressure. Although essential for initiating the measurement process, it does not display any values. Its function is purely to assist in achieving the necessary pressure in the cuff for measurement.

The pressure control valve helps regulate the release of air from the cuff during measurement. While it is important for controlling the deflation process, it does not indicate the systolic or diastolic values and is thus not used for reading blood pressure.