Final answer:
The measurement when arterial pulsations are no longer heard in the stethoscope during blood pressure measurement is the diastolic blood pressure. It represents the lowest pressure in the arteries when the heart is at rest.
Step-by-step explanation:
The measurement on the sphygmomanometer taken when arterial pulsations are no longer heard in the stethoscope is the diastolic blood pressure. This occurs as the cuff's pressure is gradually released from the upper arm. Initially, no blood flow can occur due to the inflated cuff; this is followed by the return of pulsatile blood flow, marked by the first Korotkoff sound, which corresponds to the systolic pressure, the highest pressure during the cardiac cycle. The diastolic pressure is the lower number recorded during a blood pressure reading and represents the pressure that is sustained in the arteries when the heart is in its resting phase, between beats.
A blood pressure reading consists of two numbers, such as 120/80 mm Hg. The first higher number represents the systolic pressure, and the second lower number represents the diastolic pressure. Physicians listen for the Korotkoff sounds with a stethoscope to determine these measurements. The reading is taken using devices like manual sphygmomanometers with a stethoscope or mercury manometers for high accuracy. Automated devices also exist, such as digital sphygmomanometers, which are easier to use but may lack the same level of accuracy.
Understanding the concept of systolic and diastolic blood pressure is vital for monitoring cardiovascular health. Regular blood pressure monitoring can help in the early detection of hypertension or hypotension, both of which require medical attention.