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 an essential part of the sphygmomanometer that wraps around the patient's arm and inflates to occlude blood flow. However, it does not display any measurements; its role is to create the pressure needed for obtaining blood pressure readings.

The diaphragm is a flexible membrane within the sphygmomanometer that responds to pressure changes. While it plays a crucial role in converting pressure into a readable measurement, it is not the component that displays the systolic and diastolic values directly.

The inflation bulb is used to inflate the cuff manually, allowing the healthcare provider to apply pressure to the arm. It is instrumental in the measurement process, but it does not provide any readings by itself.

The pressure control valve is used to release air from the cuff gradually, aiding in the measurement process. Despite its importance in controlling cuff pressure, it does not indicate the blood pressure values.