Chapter 17: FUNCTION OF THE HEART

A change in preload causes a change in myocardial contractile force. This response is known as (a) a. (+) inotropic effect. b. (+) dromotropic effect. c. Starling's law of the heart. d. (-) chronotropic effect.

C

Which of the following is happening during atrial systole? a. The ventricles are relaxed. b. The AV valves are closed. c. The atria pump blood into the ventricles. d. Both A and C are true.

D

Which of the following is least related to tachydysrhythmias? a. Sympathetic nervous system activation b. Beta1-adrenergic receptor activation c. (+) Dromotropic effect d. Vagal discharge

D

Which of the following is most apt to cause a (+) inotropic effect? a. Activation of the alpha1-adrenergic receptors by ACh b. Activation of the muscarinic receptors by NE c. Blockade of alpha1-adrenergic receptors d. Use of a beta1-adrenergic agonist

D

3. What happens during ventricular diastole? a. The ventricles are filling with blood. b. All semilunar valves are open. c. Both AV valves are closed. d. Blood is pumped to the lungs and systemic circulation.

A

Atropine, a muscarinic blocker, a. increases heart rate. b. causes bradycardia. c. is also classified as sympathomimetic. d. is vagomimetic.

A

Which of the following describes Starling's law of the heart? a. An increase in venous return to the ventricles causes an increase in cardiac output. b. An increase in preload increases cardiac output. c. A decrease in preload decreases cardiac output. d. All of the above are true.

D

Which of the following drugs is sympathomimetic? a. Beta1-adrenergic blocker b. Muscarinic agonist c. Vagolytic d. Beta1-adrenergic agonist

D

Which of the following elicits the same effect as vagomimetic activity? a. Beta1 blockade b. Activation of the alpha1-adrenergic receptors by ACh c. Activation of the muscarinic receptors by NE d. Use of a muscarinic agonist

D

Which of the following is least likely to increase cardiac output? a. Increased heart rate b. Increased stroke volume c. Increased venous return d. Vagal discharge

D

Which of the following is most likely to relieve an anxiety-induced tachycardia? a. Vagolytic drug b. Beta1-adrenergic agonist c. Sympathomimetic d. Beta1-adrenergic blocker

D

Which of the following is not the result of the firing of the sympathetic nerves on the heart? a. (+) Inotropic effect b. (+) Chronotropic effect c. Increased heart rate d. Vagally induced bradycardia

D

Which of the following is responsible for the Starling effect? a. Sympathetic nerve firing b. Vagal discharge c. Activation of the beta1-adrenergic receptors d. End-diastolic volume (EDV) or preload

D

Which of the following refers to a positive inotropic effect? a. Heart block b. A slow heart rate c. A rapid heartbeat d. An increased myocardial contractile force

D

Atropine is a muscarinic antagonist and is therefore used to a. relieve bradycardia. b. decrease heart rate. c. block the effects of norepinephrine. d. increase myocardial contractile force.

A

Cor pulmonale refers to a. elevation in pulmonary artery pressure and right ventricular hypertrophy. b. backward failure and pulmonary edema. c. pulmonary edema. d. a major cause of left ventricular failure.

A

Jugular vein distention is most associated with a. right-sided heart failure. b. aortic valve stenosis. c. left wall infarct and left ventricular failure. d. low volume shock right-sided heart failure.

A

Sympathetic nerve stimulation of the myocardium a. causes a (+) inotropic effect. b. decreases cardiac output. c. decreases heart rate. d. decreases stroke volume.

A

Which term refers to a heart rate less than 60 beats/min? a. Bradycardia b. Heart block c. Fight-or-flight response d. Tachycardia

A

Which of the following statements is correct about cardiac output? a. Cardiac output is determined by the heart rate and pulse. b. Stimulation of the sympathetic nerves decreases cardiac output. c. Vagal discharge increases cardiac output. d. Cardiac output is determined by heart rate and stroke volume.

D

What is the term that refers to an increase in stroke volume in response to the stretching of the heart? a. Starling's law of the heart b. A positive inotropic effect c. Heart block d. Angina pectoris

A

Which of the following does not happen during ventricular diastole? a. Blood is being pumped into the great vessels. b. The semilunar valves are closed. c. Blood is filling the ventricles. d. Blood is flowing from the atria into the ventricles.

A

Which of the following is least related to a bradycardia? a. Greater than 60 beats/min b. Vagal discharge c. (-) Chronotropic effect d. Parasympathetic nerve stimulation of the SA node

A

Which of the following is most likely to increase ejection fraction? a. Activation of beta1-adrenergic receptors b. Vagal discharge c. Blockade of beta1-adrenergic receptors d. Activation of the muscarinic receptors

A

Which of the following is most likely to increase stroke volume? a. A (+) inotropic drug b. A vagolytic drug c. A (-) chronotropic drug d. A beta1-adrenergic blocker

A

Which of the following is the most likely consequence of a very rapid heart rate? a. Decreased ventricular filling (with blood) b. Failure of the AV valves to open c. Failure of the SA node to fire d. Failure of the cardiac impulse to enter the His-Purkinje system

A

Venodilation a. increases afterload. b. decreases preload. c. increases end-diastolic volume. d. stretches the ventricular myocardium.

B

Which of the following defines cardiac output? a.Cardiac index ejection fraction b. Heart rate stroke volume c.Stroke volume ejection d.fraction Afterload heart rate

B

Under what condition is end-diastolic volume (EDV) most likely to increase while ejection fraction decreases? a. Exercise b. Sympathetic nerve stimulation c. (+) Inotropic response d. Heart failure

D

A drug (e.g., atropine) that blocks the effects of the vagus nerve a. stops the heart. b. increases heart rate. c. decreases cardiac output. d. decreases stroke volume.

B

A stenotic aortic valve a. causes right ventricular hypertrophy and right-sided heart failure. b. increases afterload, thereby increasing the work of the left ventricle. c. causes a right-to-left shunt. d. is a narrowing of the right semilunar valve.

B

A very anxious person appears in the ER. He has a heart rate of 160 beats/min and indicates that he has a history of panic attacks. He is prescribed an antianxiety agent and a drug to slow his heart rate. Identify the drug (to slow heart rate). a. Muscarinic antagonist b. Beta1-adrenergic blocker c. Sympathomimetic d. Vagolytic

B

An increased preload a. decreases cardiac output. b. increases stroke volume. c. increases cardiac reserve. d. increases afterload.

B

Cardiac output is determined by heart rate and a. systemic vascular resistance. b. stroke volume. c. hematocrit. d. hemoglobin concentration.

B

During atrial systole, the a. AV valves are closed. b. ventricles are relaxed. c. ventricles are in systole. d. semilunar valves are open.

B

Excess vagal stimulation to the SA node is most likely to cause a. hypertension. b. bradycardia. c. tachycardia. d. anemia.

B

Increased afterload (e.g., hypertension) a. is usually caused by arteriolar dilation. b. increases the work of the heart. c. can only occur when preload increases. d. is usually caused by intense parasympathetic (vagal) discharge.

B

Increased return of blood to the heart stretches the heart muscle, thereby a. stimulating the vagus nerve. b. increasing stroke volume. c. closing the atrioventricular valves. d. increasing coronary blood flow.

B

Starling's law of the heart relates force of myocardial contraction with a. heart rate. b. preload. c. end-systolic volume. d. blood pressure.

B

Sympathetic stimulation to the heart a. decreases stroke volume. b. increases heart rate. c. causes bradycardia. d. decreases cardiac output.

B

Vagal stimulation to the heart causes a. a (+) inotropic effect. b. heart rate to slow. c. cardiac output to increase. d. stroke volume to increase.

B

Which of the following is an example of forward failure? a. Blood accumulates in the pulmonary capillaries, elevating pressure and causing pulmonary edema. b. Diminished renal blood flow stimulates the kidney to decrease urinary output and retain Na+ and water. c. Blood distends the jugular vein. d. Blood distends the liver, causing hepatomegaly and digestive symptoms.

B

Which of the following is descriptive of a drug that causes a (+) inotropic effect, a (+) dromotropic effect, and a (+) chronotropic effect? a. Vagomimetic b. Sympathomimetic c. Antimuscarinic d. Vagolytic

B

Which of the following is descriptive of the vagus nerve? a. Fight-or-flight b. Parasympathetic c. Sympathetic d. Adrenergic

B

Which term refers to the amount of blood pumped by the heart in 1 minute? a. Stroke volume b. Cardiac output c. Starling's law of the heart d. Inotropic effect

B

With which of the following is inotropism most associated? a. Heart rate b. Force of myocardial contraction c. Oxygen saturation d. Systemic vascular resistance

B

With which term is preload synonymous? a. Cardiac reserve b. End-diastolic volume c. Afterload d. Ejection fraction

B

Vagal stimulation on the heart a. increases the force of myocardial contraction. b. increases the amount of blood that flows into the heart from the vena cava. c. causes tachycardia. d. slows the heart rate.

D

A patient in heart failure is given a drug that is classified as a beta1-adrenergic agonist. The drug a. blocks the beta1-adrenergic receptors and causes a (-) chronotropic and (-) inotropic effect. b. activates the beta1-adrenergic receptors and causes bronchoconstriction. c. activates the beta1-adrenergic receptors and causes a (+) inotropic effect. d. activates the vagus nerve, thereby slowing heart rate and strengthening myocardial contraction.

C

An ejection fraction of 30% is a. normal. b. characteristic of a healthy person who is engaged in aerobic exercise. c. characteristic of a failing heart. d. the amount of oxygenated hemoglobin in the blood in the left ventricle.

C

An elevation in pulmonary artery pressure is most likely to cause a. pleural effusion. b. pulmonary edema. c. right ventricular hypertrophy. d. left ventricular failure and pulmonary edema.

C

An increase in venous return causes an increase in cardiac output. This is accomplished by a. a (+) inotropic effect. b. depolarization. c. Starling's law of the heart. d. a (+) chronotropic effect.

C

Decreased blood flow through the coronary arteries is most likely to cause a. valve damage. b. pulmonary edema. c. angina pectoris. d. bradycardia.

C

Digoxin, a drug used in the treatment of heart failure, increases contractile force and is therefore called a a. diuretic. b. (+) dromotropic agent. c. (+) inotropic agent. d. (+) chronotropic agent.

C

Furosemide (Lasix), a potent diuretic, is administered in acute ventricular failure to a. strengthen myocardial contractile force. b. increase plasma K+ levels. c. excrete excess water and relieve the edema. d. relieve pain.

C

Heart rate and stroke volume determines a. hematocrit. b. total blood volume. c. cardiac output. d. the size of the heart valves.

C

Most of the symptoms of acute left-sided heart failure are a. relieved by morphine. b. cured by an antibiotic. c. respiratory in nature (e.g., dyspnea, orthopnea). d. confined to the lower extremities, as in pedal edema.

C

Systole and diastole describe the function of the a. pericardium. b. SA node. c. myocardium. d. mediastinum.

C

What is the term for the sequence of events that occur during one heartbeat? a. Stroke volume b. Cardiac output c. Cardiac cycle d. Systole

C

Which of the following does not happen to a ventricle? a. Activation of the beta1-adrenergic receptors b. Discharge of sympathetic nerves c. Discharge of the vagal nerve d. Binding of norepinephrine to its receptor

C

Which of the following is approximately 70 mL? a. The cardiac output b. The volume of a ventricle c. An average stroke volume d. The amount of blood that flows through the pulmonary capillaries in one minute

C

Which of the following is least likely to be used in the treatment of left ventricular failure and pulmonary edema? a. (+) Inotropic agent such as digoxin or dopamine b. Diuretic such as furosemide (Lasix) c. Peripheral vasoconstrictor such as norepinephrine (Levophed) d. Oxygen

C

Which of the following is most apt to induce an autonomically induced bradycardia? a. Secretion of norepinephrine by the postganglionic adrenergic fibers b. Activation of the beta1-adrenergic receptors c. Activation of the muscarinic receptors d. Sympathetic nerve stimulation

C

Which of the following is the best description of systole and diastole? a. Atria and ventricles b. Depolarization and repolarization c. Contraction and relaxation d. Heart rate and stroke volume

C

Which of the following is the most likely consequence of acute left ventricular failure? a. Jugular vein distention b. Hepatomegaly and splenomegaly c. Pulmonary edema d. Pedal edema

C

Which of the following is the same as end-diastolic volume? a. Stroke volume b. Cardiac output c. Preload d. Cardiac reserve

C

Which of the following most accurately describes the vagus nerve? a. Fight or flight b. Norepinephrine c. Parasympathetic d. Causes tachycardia

C

With which term is afterload most associated? a. Preload b. End-diastolic volume c. Resistance d. Hypoxemia

C

Ventricular systole refers to a. ventricular depolarization. b. the opening of the valves of the ventricles. c. ventricular filling. d. contraction of the ventricular myocardium.

D

A drug causes a (+) inotropic effect, a (-) dromotropic effect, and a (-) chronotropic effect. What drug response would you expect to observe? a. Tachycardia b. Low blood pressure c. Ankle edema d. Slow heart rate

D

Activation of the muscarinic receptors by acetylcholine a. increases myocardial contractile force. b. causes a (+) chronotropic effect. c. increases cardiac output. d. slows heart rate.

D

Atropine is anticholinergic and antimuscarinic and therefore a. causes a (+) inotropic effect. b. increases the force of myocardial contraction. c. decreases heart rate. d. is used to treat bradydysrhythmias such as heart block and a prolonged P-R interval.

D

Cardiac output a. is determined by heart rate and pulse. b. decreases in response to sympathetic nerve stimulation. c. increases in response to vagal discharge. d. is determined by heart rate and stroke volume.

D

Digoxin exerts a (-) chronotropic effect and (+) inotropic effect. Which of the following describes these effects? a. Slows heart rate and decreases cardiac output b. Increases heart rate and increases systemic vascular resistance c. Decreases heart rate and decreases stroke volume d. Decreases heart rate and strengthens myocardial contraction

D

Increased return of the blood to the heart stretches the muscle, thereby a. stimulating the sympathetic nerve. b. activating the beta1-adrenergic receptors. c. closing the AV valves. d. increasing stroke volume.

D

Milliliters per minute describes a. stroke volume. b. heart rate. c. pulse. d. cardiac output.

D

Milliliters/beat beats/min defines a. stroke volume. b. ejection fraction. c. cardiac reserve. d. cardiac output.

D

The amount of blood in the ventricle at the end of its resting phase is the a. end-diastolic volume (EDV). b. amount of blood in the ventricle at the end of its resting phase. c. preload. d. All of the above are true.

D

What term refers to the amount of blood pumped by the ventricle in one beat? a. Cardiac output b. Blood volume c. Hematocrit d. Stroke volume

D