Quiz 2 Biol 224

Analysis of the electrocardiogram can reveal all of the following except 1. stroke volume. 2. the condition of the conducting system. 3.the duration of the ventricular action potential 4..the effects of drugs and poisons.heart rate.

1

Compared to the right ventricle, the left ventricle has all the following characteristics except 1. has a thicker wall. 2. works harder. 3. pumps a greater volume. 4. produces about four to six times more pressure when it contracts 5. .is round in cross section.

2

Which of the following would not increase heart rate? 1. increased sympathetic stimulation of SA node 2. decreased parasympathetic stimulation of nodal fibers 3. faster depolarization of the pacemaker potential 4. increased levels of epinephrine 5. beta blocking drugs

5

Calculate the cardiac output of a patient with a heart rate of 100 beats/minute and a stroke volume of 75 ml.

7500 ml / min

Abnormally slow depolarization of the ventricles would most change the shape of the ________ in an ECG tracing.

QRS complex

During the plateau phase of the cardiac action potential, which ion is entering the cardiac muscle cell?

calcium

Which of the following is occurring during ventricular diastole?

The ventricles are passively filling and atria are contracting.

The first heart sound ("lubb") is associated with

closing of the atrioventricular valves.

The ________ is the volume of blood in a ventricle at the beginning of systole.

end-diastole volume

Passive refilling of the heart occurs during which phase of the cardiac cycle?

ventricular diastole