A patient who has coronary artery
disease is treated with a drug that
reduces heart rate by 10% without
changing stroke volume. Furthermore,
the drug is found to decrease mean
arterial pressure by 10%. Assume that
central venous pressure remains at 0 mm
Hg. This drug
a. Decreases systemic vascular resistance
by 10%.
b. Does not alter cardiac output.
c. Does not alter systemic vascular
d. Reduces pressure by dilating the
systemic vasculature.
Which of the following will increase
blood flow to the greatest extent in
a single isolated blood vessel that is
perfused with blood in vitro at a con-
stant perfusion pressure?
a. Decreasing the blood temperature by
b. Increasing perfusion pressure by 100%
c. Increasing blood viscosity by 100%
d. Increasing the vessel diameter by 50%
If cardiac output is 4500 mL/min, mean
arterial pressure is 94 mm Hg, and right
atrial pressure is 4 mm Hg, systemic vas-
cular resistance (in peripheral resistance
units, PRU; mm Hg/mL ■
min-1) is
a. 0.02
b. 20
c. 50
d. 4.05 x 105
A patient recently diagnosed with
hypertension is found to have a stenotic
(narrowed) right renal artery. The inter-
nal diameter is reduced by 50%. Assum-
ing that renal artery resistance is 1% of
total renal resistance and that vascular
resistance in the kidney is unchanged,
blood flow to the right kidney will
decrease by what amount?
a. 50%
b. <20%
c. 8-fold
d. 16-fold
A patient in the Emergency Department
with traumatic injuries from an automo-
bile accident suddenly shows a fall in arte-
rial pressure accompanied by an increase
in central venous pressure. These hemo-
dynamic changes could be explained by
a. A sudden fall in cardiac output.
b. Increased systemic venous
c. Loss of blood volume.
d. Sympathetic activation.
Venous return to the right atrium is
a. Decreased as cardiac output increases.
b. Decreased by sympathetic activation
of veins.
c. Increased during a forced expiration
against a closed glottis.
d. Increased during inspiration.
Mean circulatory filling pressure is
increased by
a. Decreased venous compliance.
b. Increased systemic vascular resistance.
c. Decreased blood volume.
d. Increased cardiac output.
10. In a normal heart, cardiac output and
right atrial pressure are both increased by
a. Decreased blood volume.
b. Decreased systemic vascular
c. Increased heart rate.
d. Increased venous compliance.
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