phy 25 - aimhigh

[ArchivalUser]

31. A 67-year-old man complains that he tires easily and
has frequent chest pain. A series of tests performed by a
cardiologist leads to a diagnosis of aortic regurgitation.
His mean arterial blood pressure is normal. Which of
the following sets of changes are present in this man,
compared with normal? (LVEDV = left ventricular end
diastolic volume)
Pulse Pressure, Diastolic BloodPressure, SystolicBloodPressure, LVEDV (A) ↑ ↓ ↑ ↑
(B) ↑ ↓ ↑ ↓
© ↔ ↔ ↔ ↔
(D) ↓ ↑ ↑ ↑
(E) ↓ ↔ ↓ ↓

[ArchivalUser]

A?

[ArchivalUser]

b.

[ArchivalUser]

A.

[ArchivalUser]

B...

[ArchivalUser]

sorry...would go with A

[ArchivalUser]

The correct answer is A. The pulse pressure (systolic
pressure “ diastolic pressure) increases in aortic regurgitation
because 1) the arterial blood leaks backward
through the aortic valve during diastole, which decreases
the diastolic blood pressure, and 2) the increase in
end-diastolic volume that results from this extra blood
in the ventricle causes a large increase in the stroke volume.
The increase in stroke volume raises the systolic
blood pressure. The mean blood pressure is usually
normal in aortic regurgitation.

[ArchivalUser]

thz

[ArchivalUser]

30. The correct answer is C. The various organs of the
body are arranged in parallel and therefore contribute a
parallel resistance to the peripheral circulation. Adding
resistances in parallel reduces the total resistance (RT)
of a circuit in accordance with the following formula: 1/
RT = 1/R1 + 1/R2 + 1/R3 Thus, removing a parallel
resistance (R1, R2, or R3) increases the total resistance
(RT). For this reason, the total peripheral resistance
increases when a kidney (or any other organ) is
removed. It should be clear that the total peripheral
resistance will be decreased during resting conditions as
well as during exercise, but not only during exercise
(choice D). The increase in total peripheral resistance
caused by removing a kidney is a physical effect, independent
of metabolic rate (choice E).

[ArchivalUser]

uuuppsss feeling sleepy