Exam 9: Cardiac Physiology

The Frank-Starling law of the heart relates to how stretching of the ventricles during ventricular filling will affect stroke volume.

Use the following answer code to indicate which factor involved in the initiation and spread of cardiac excitation is being identified a.SA node b.AV node c.bundle of His and Purkinje system d.gap junctions -Rapidly conducts the impulse down the ventricular septum and throughout much of the ventricular musculature

Use the following answer code to compare the magnitude of the items in question. a.A is greater than b.b.B is greater than a.c.A and B are equal or nearly equal. -a.Normal stroke volume B.Stroke volume on sympathetic stimulation

Match EKG feature with the correct characteristic. a.P wave b.QRS complex c.T wave d.PR interval e.TP interval f.ST segment -Time during which atria are repolarizing

Use the following answer code to indicate which factor involved in the initiation and spread of cardiac excitation is being identified a.SA node b.AV node c.bundle of His and Purkinje system d.gap junctions -Normal pacemaker of the heart

If stroke volume is 80 ml and the heart rate is 70 beats per minute, the cardiac output is

An increase in afterload will cause the heart to remain longer in the period of isovolumetric relaxation.

The primary function of the pericardial sac is to

Which of the following is not occurring at the same time when the QRS complex appears on an ECG?

Vasodilation of coronary arteries is induced by

Use this figure to answer the corresponding questions. -The structure labeled 1 a.allows blood to pass into the ventricle b.has deoxygenated blood flowing past it c.is connected to chordae tendineae d.all of these e.none of these

The average resting heart rate is normally established by the rhythm of autorhythmic cells located near the base of the right atrium.

The cardiac output is equal to

An increase in cardiac sympathetic activity ____________________ the velocity of impulse conduction through the heart.

Using the following answer code, indicate which pressure relationship exists during the time in question. a.aortic pressure > ventricular pressure > atrial pressure b.aortic pressure > ventricular pressure < atrial pressure c.aortic pressure < ventricular pressure > atrial pressure d.aortic pressure < ventricular pressure < atrial pressure -When ventricular ejection is occurring

A heart valve opens and closes due to

An increase in parasympathetic activity ____________________ the stroke volume.

An ectopic focus is the place where

At rapid heart rates

Stroke volume is inversely correlated to preload; i.e., a lower preload increases stroke volume.