Final answer:
It is true that a sphygmomanometer is used to measure blood pressure. This device, which includes an inflatable cuff and a manometer, allows for the audible detection of the systolic and diastolic blood pressures during the measurement process.
Step-by-step explanation:
The statement that blood pressure is measured directly with a sphygmomanometer is true. A sphygmomanometer includes an inflatable cuff designed to constrict blood flow and a manometer to measure the pressure. When the cuff is inflated around the upper arm and tightens to the point of stopping the arterial blood flow, the measurement begins. The pressure is then gradually released, and as the blood starts to surge through the brachial artery again, audible noises known as Korotkoff sounds can be heard with a stethoscope. The systolic pressure, which is the higher number of a blood pressure reading, is identified when these sounds first appear. The diastolic pressure, the lower number, is determined when the sounds cease, indicating free blood flow without the cuff's constriction.