Blood pressure is a measure of
A. oxygen levels in the blood.
B. the ratio of red blood cells to white blood cells.
C. how hard the heart is working.
D. the pressure exerted by hemoglobin against the vascular walls.
D.
C, hemoglobin is the oxygen-carrying portion of red blood cells.
The correct answer is D. Blood pressure is the pressure exerted by the blood against the walls of the blood vessels, specifically the arteries. It is a measure of the force of blood flow through the circulatory system. To determine blood pressure, two values are measured: systolic pressure and diastolic pressure. Systolic pressure represents the maximum pressure exerted on the arterial walls when the heart contracts, while diastolic pressure represents the minimum pressure exerted on the arterial walls when the heart is at rest between beats.
To measure blood pressure, a device called a sphygmomanometer is typically used. It consists of an inflatable cuff that is wrapped around the upper arm, a pressure meter, and a stethoscope or electronic sensor. The cuff is inflated to temporarily stop blood flow in the artery, and then slowly released while listening for the sound of blood flowing. The pressure reading is recorded when the sound is first heard (systolic pressure) and when the sound disappears (diastolic pressure).
High blood pressure (hypertension) can be an indicator of underlying health issues, such as cardiovascular disease, kidney problems, or lifestyle factors like diet and exercise. Low blood pressure (hypotension) can also be a concern and may suggest an underlying medical condition or medication side effects. It is important to monitor and maintain regular blood pressure levels to ensure overall cardiovascular health.