Chapter 13: Cardiac Function

The opening and closure of the atrioventricular and semilunar valves is driven by _____.

Closure of the atrioventricular valve occurs when _____.

What is the primary function of the AV and semilunar valves?

Whereas the contractile activity of skeletal muscle is called ________, that of cardiac muscle is ________ because the contraction originates within the musculature itself.

What two major regions of the heart contain a concentration of pacemaker cells?

The term autorhythmicity refers to the heart's ability to ____.

Which of the following is the correct conduction pathway through the heart?

Conduction through which of the following is slow to allow atria to contract before the ventricles?

The rapid depolarization phase of a pacemaker cell action potential is caused by movement of _____.

What causes the rapid depolarization phase of a contractile cell action potential?

During repolarization (phase 3) of a contractile cell action potential, _____.

Which of the following ion channels does NOT participate in the contractile cell action potential?

Which of the following is NOT a part of the excitation-contraction coupling in cardiac muscle?

What is the function of the sodium-calcium exchanger in cardiac muscle?

Which of the following components of an ECG represents atrial depolarization?

Which of the following components of an ECG represents ventricular depolarization?

Which of the following components of an ECG represents ventricular repolarization?

Which statement best describes why atrial repolarization is usually not detected on a normal ECG?

The Q-T interval is the time from the onset of the QRS complex to the end of the T wave which measures

The T-Q segment is the time from the end of the T wave to the beginning of the QRS complex which measures the time ____.

The R-R interval is the time between the peaks of two successive QRS complexes and represents ____.

In an ECG recording, the RR interval is 0.5 seconds. What is the heart rate?

Which statement best describes why clinicians use a defibrillator?

During isovolumetric relaxation, _____.

What is occurring during ventricular ejection?

Which of the following is TRUE of the ventricular filling phase of the cardiac cycle?

What phase of the cardiac cycle is the heart in when all four valves of the heart are closed and ventricular pressure is building, but is not yet great enough to open a valve?

During which phase of the cardiac cycle are all four heart valves open?

Ejection of blood from the right ventricle will continue until _____.

The increase in ventricular volume early in diastole reflects the ____.

The small increase in ventricular pressure observed late in diastole is caused by _____.

Blood is ejected from the left ventricle once pressure within the_____.

The increased aortic pressure that occurs during systole reflects a(n) _____.

The end-diastolic volume minus the end-systolic volume is the _____.

The volume of blood ejected from the ventricle with each contraction can be described by the equation _____.

Given end-diastolic volume = 130 mL and end-systolic volume = 50 mL, what is the stroke volume and ejection fraction?

What causes the sounds that one hears as the heart beats?

Cardiac output is determined by what two variables?

Regulation of the heart (or any organ or tissue) by neural input, circulating hormones, or any other factor originating from outside the organ is referred to as ________ control.

Which of the following structures is poorly innervated by the parasympathetic nervous system and, therefore, an increase in parasympathetic activity has little effect on this structure?

The SA node is innervated by the ____.

Which of the following is an effect of parasympathetic activity to the heart?

Which of the following is a FALSE statement about sympathetic activity to the SA node?

Under resting conditions, heart rate is primarily under the control of what control system?

An increase in heart rate can be mediated through which of the following?

Which of the following would NOT result from an increase in ventricular contractility?

Which of the following variables is NOT an intrinsic factor that alters cardiac function?

The preload is approximately the same as the ________ pressure.

Which of the following factors determines preload?

An increase in venous return would result in a(n) ____.

Which of the following variables is NOT involved in determining ventricular preload?

A decrease in afterload will lead to which of the following?

Which of the following decreases heart rate?

Which component of an ECG represents ventricular depolarization?

Which component of an ECG represents atrial depolarization?

Which component of an ECG represents ventricular repolarization?

Which component of an ECG represents ventricular systole?

Which component of an ECG represents ventricular diastole?

Which component of an ECG represents the AV nodal conduction time?

In what phase is the cardiac cycle when all four valves are closed and pressure in the ventricle is decreasing?

In what phase of the cardiac cycle does ventricular pressure exceed aortic pressure?

In what phase is the cardiac cycle when the AV valves are open and semilunar valves are closed?

In what phase is the cardiac cycle when the semilunar valves are open and AV valves are closed?

The second heart sound coincides with the beginning of which period in the cardiac cycle?

What component of the conduction pathway transmits the action potential to the ventricular contractile cells?

What is the pacemaker of the heart?

The initial depolarization that occurs in pacemaker cells is caused by closing of ________ channels and opening of ________ channels.

The rapid depolarization phase of the action potential in the pacemaker cells is driven by the rapid influx of ________ ions through ________ channels.

The period of ventricular contraction is called ________, whereas the period of ventricular relaxation is called ________.

The P wave of the electrocardiogram is created by ____.

The repolarization of the ventricle is reflected in the ________ of the electrocardiogram.

The volume of blood that is pumped by the heart every minute is determined by the equation

What is the equation relating stroke volume (SV), end-diastolic volume (EDV), and end-stroke volume (ESV)?