1) If Lucy had all of the pacemaker cells in her AV node dieoff, what would happen?
A. Her heart would still beat at a normal rate as if nothinghappened.
B. Her heart would stop beating and she would die.
C. Her heart rate would be controlled by the pacemaker cells of theBundle of His . Her heart rate would start depolarizing from theapex.
D. Her heart would still beat, but the ventricles would contractright before the atria, instead of the opposite.
2) Which of the following is a true statement aboutcapillaries?
A. At the efferent end, osmotic pressure is usually less thanhydrostatic pressure.
B. They are leaky to everything but plasma and red bloodcells.
C. Most of the water that leaves the capillary via ultrafiltrationis brought back into the capillary via reabsorption.
D. All of the above are true.
E. None of the above is true.
3) Which of the following is a true statement?
A. The endocardium is the muscle layer of the heart.
B. The epicardium is a thick fibrous layer that is filled withfluid.
C. Without any autonomic N.S. influence, a heart would contract at~70-80 beats per minute.
D. All of the above are true.
E. None of the above is true.
4) If Brown was injected with a drug that blocked all autonomicsignalling to the heart, what would happen to him?
A. His heart would stop beating and he would die.
B. His heart would still beat, but much slower than a normalperson's.
C. His heart would beat at about 50-60 beats per minute
D. He would be unaffected because the autonomic nervous systemdoesn't go to the heart.
E. His heart rate would remain a constant 70-80 beats per minuteregardless if he was resting or exercising.
5) Brown is injected with a drug that blocks all of thevoltage-gated Ca2+ channels, but only on his myocardial cells. Whatwill happen to Brown?
A. His heart rate will increase dramatically.
B. His heart will contract with more force.
C. The pacemaker cells will no longer be able to fire actionpotentials.
D. His heart would stop contracting at all.
E. He would be unaffected, because there are no voltage-gatedchannels on myocaridal cells.
