Emergency Medical Technician (EMT) Intermediate Practice Exam

Mean arterial pressure (MAP) is:

1. The average blood pressure in a person's arteries during one cardiac cycle

2. The pressure experienced in the right atrium

3. The pressure at which the heart contracts

4. The blood pressure recorded during diastole

The correct answer is: The average blood pressure in a person's arteries during one cardiac cycle

Mean arterial pressure (MAP) is indeed defined as the average blood pressure in a person's arteries during one cardiac cycle. This measure is crucial as it reflects the perfusion pressure reaching the organs and tissues throughout the body, making it an effective indicator of overall blood flow and cardiovascular health. MAP is calculated using the diastolic blood pressure and systolic blood pressure, typically using the formula: MAP = DBP + 1/3(SBP - DBP). Understanding MAP is essential in clinical settings to assess a patient's hemodynamic status, especially in critically ill patients or those with hypotension or hypertension. The remaining options refer to different aspects of cardiovascular physiology. The pressure experienced in the right atrium is not a measure of mean arterial pressure but rather reflects central venous pressure, which is important for understanding right heart function and fluid status. The pressure at which the heart contracts refers to systolic pressure, which is one component of MAP but does not encompass the average arterial pressure throughout the entire cardiac cycle. Lastly, the blood pressure recorded during diastole refers only to diastolic blood pressure, which is again a component of MAP but insufficient by itself to describe the average pressure experienced in the arteries over time.