Try it
Physiology · Cardiovascular physiology: blood pressure
Sample itemA patient's blood pressure is 150/90 mmHg. Using diastolic pressure plus one-third of pulse pressure, what is the mean arterial pressure?
Original practice item, not a recalled exam question. Nothing here is recorded.
The answer and the reasoning
D. 110 mmHg
Pulse pressure is 150 minus 90, which is 60 mmHg. One-third of this is 20, so the mean arterial pressure is 90 plus 20, which is 110 mmHg. The mean lies closer to diastolic pressure because diastole occupies more of the cardiac cycle than systole at a normal heart rate.
Option by option
A. 90 mmHg
This is just the diastolic pressure and ignores the contribution of pulsatile pressure.
B. 130 mmHg
This comes from adding two-thirds of the pulse pressure to diastolic pressure, which is the wrong fraction.
C. 120 mmHg
This is the simple average of systolic and diastolic pressure, which overestimates mean pressure because diastole is longer than systole.
D. 110 mmHg (correct)
Correct. Diastolic pressure plus one-third of pulse pressure gives 110 mmHg.
Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.
More Physiology questions
- Cardiac cycleDuring which phase of the cardiac cycle are all valves closed while ventricular pressure…
- Renal physiologyWhich substance is freely filtered and neither reabsorbed nor secreted, so that its clea…
- RespirationWhich of the following shifts the oxygen–haemoglobin dissociation curve to the right?
- Renal physiologyWhich of the following favours glomerular filtration?