Structure and Function 6
Excess vagal stimulation to the SA node is most likely to cause a. hypertension. b. bradycardia. c. tachycardia. d. anemia.
bradycardia.
Milliliters per minute describes a. stroke volume. b. heart rate. c. pulse. d. cardiac output.
cardiac output.
Milliliters/beat beats/min defines a. stroke volume. b. ejection fraction. c. cardiac reserve. d. cardiac output.
cardiac output.
Which of the following drugs is sympathomimetic? a. Beta 1 -adrenergic blocker b. Muscarinic agonist c. Vagolytic d. Beta 1 -adrenergic agonist
Beta 1 -adrenergic agonist
A very anxious person appears in the ER. He has a heart rate of 160 b/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. Beta 1 -adrenergic blocker c. Sympathomimetic d. Vagolytic
Beta 1 -adrenergic blocker
Which of the following is a result of ventricular contraction? a. The AV valves open. b. The semilunar valves close. c. Blood is pumped into the pulmonary artery and the aorta. d. Blood flows back into the atria.
Blood is pumped into the pulmonary artery and the aorta.
Which term refers to a heart rate less than 60 beats/min? a. Bradycardia b. Heart block c. Fight-or-flight response d. Tachycardia
Bradycardia
Which of the following is true about the left ventricular myocardium? a. Pumps blood into the pulmonary artery b. Contraction is caused by the sliding of actin and myosin c. Receives oxygenated blood from the precordium d. Contains unoxygenated blood
Contraction is caused by the sliding of actin and myosin
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
Contraction and relaxation
Cells that spontaneously depolarize from resting membrane potential to threshold potential a. are called pacemaker cells. b. normally "live" within the chordae tendineae. c. are restricted to the SA node. d. are stored within the pericardium.
are called pacemaker cells.
Which of the following is true of the myocardium? a. Contains thick and thin filaments b. Contains actin and myosin c. Is thicker in the left ventricle than in the right ventricle d. All of the above
d. All of the above
The aorta receives blood from the a. right ventricle. b. pulmonary veins. c. pulmonary artery. d. left ventricle.
left ventricle.
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.
left ventricular failure and pulmonary edema
The heart a. lies within the mediastinal, thoracic, and ventral cavities. b. beats only in response to stimulation by the autonomic nerves. c. is located within the pleural cavity. d. is located between the fifth and twelfth ribs in the left thoracic region.
lies within the mediastinal, thoracic, and ventral cavities.
Starling's law of the heart relates force of myocardial contraction with a. heart rate. b. preload. c. end-systolic volume. d. blood pressure.
preload.
The right ventricle pumps blood to the a. right atrium. b. pulmonary veins. c. pulmonary artery. d. aorta.
pulmonary artery.
The correct sequence is: Blood flows from the right atrium to the right ventricle to the pulmonary artery to the a. pulmonary veins. b. coronary arteries. c. pulmonary capillaries. d. vena cava.
pulmonary capillaries.
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.
relieve bradycardia
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.
respiratory in nature (e.g., dyspnea, orthopnea)
The pacemaker of the heart is located in the upper wall of the a. right atrium. b. right ventricle. c. left atrium. d. left ventricle.
right atrium
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.
right-sided heart failure
During atrial systole, the a. AV valves are closed. b. ventricles are relaxed. c. ventricles are in systole. d. semilunar valves are open.
ventricles are relaxed.
During ventricular filling, the a. semilunar valves are open. b. AV valves are closed. c. QRS complex is "happening." d. ventricles are relaxed.
ventricles are relaxed.
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.
(+) inotropic agent.
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 beta 1 -adrenergic blocker
A (+) inotropic drug
The purpose of this structure is to delay the spread of the signal from the atrium to the ventricles. a. SA node b. Purkinje fibers c. Bundle of His d. AV node
AV node
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
An average stroke volume
What event causes the pulmonic valve to open? a. The P wave b. An increase in the pressure within the right ventricle c. "Lubb-dupp" d. Contraction of the chordae tendineae
An increase in the pressure within the right ventricle
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
An increased myocardial contractile force
Which structure is not perfused by the blood that is pumped from the right ventricle to the left ventricle? a. Mitral valve b. Pulmonary artery c. Pulmonary veins d. Aorta
Aorta
Chordae tendineae are not associated with this valve. a. Aortic b. Mitral c. Tricuspid d. Bicuspid
Aortic
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.
Cardiac output is determined by heart rate and stroke volume
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
Decreased ventricular filling (with blood)
Which of the following is an electrical event? a. "Lubb-dupp" b. Actin and myosin interaction c. Murmur d. Depolarization
Depolarization
With which of the following are these words most related: electrical signal, action potential, cardiac impulse, and nerve impulse? a. Tricuspid and mitral atrioventricular valves b. Aortic and pulmonic semilunar valves c. Depolarization and repolarization d. Contraction and relaxation
Depolarization and repolarization
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.
Diminished renal blood flow stimulates the kidney to decrease urinary output and retain Na + and water.
Which of the following does not happen to a ventricle? a. Activation of the beta 1 -adrenergic receptors b. Discharge of sympathetic nerves c. Discharge of the vagal nerve d. Binding of norepinephrine to its receptor
Discharge of the vagal nerve
When is coronary blood flow greatest? a. During ventricular contraction b. Immediately following the QRS complex on the ECG c. During ventricular diastole d. During ventricular systole
During ventricular diastole
With which term is preload synonymous? a. Cardiac reserve b. End-diastolic volume c. Afterload d. Ejection fraction
End-diastolic volume
Which of the following is responsible for the Starling effect? a. Sympathetic nerve firing b. Vagal discharge c. Activation of the beta 1 -adrenergic receptors d. End-diastolic volume (EDV) or preload
End-diastolic volume (EDV) or preload
With which of the following is inotropism most associated? a. Heart rate b. Force of myocardial contraction c. Oxygen saturation d. Systemic vascular resistance
Force of myocardial contraction
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
Heart failure
Which of the following defines cardiac output? a. Cardiac index ejection fraction b. Heart rate stroke volume c. Stroke volume ejection fraction d. Afterload heart rate
Heart rate stroke volume
Which of the following is true of the structures of the electrical conduction system? a. The AV valve is the pacemaker. b. In normal sinus rhythm, the electrical signal arises within the SA node. c. The His-Purkinje system spreads the electrical system from the right atrium to the left atrium. d. The purpose of the AV node is to increase the speed at which the cardiac impulse moves from the atria to the ventricles.
In normal sinus rhythm, the electrical signal arises within the SA node.
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.
Is used to treat bradydysrhythmias such as heart block and a prolonged P-R interval.
Which of the following is true of the aorta? a. It distributes unoxygenated blood to the systemic circulation. b. It distributes oxygenated blood to the pulmonic circulation. c. It arises within the left ventricle. d. It is color coded blue to indicate its degree of oxygen saturation.
It arises within the left ventricle
Which of the following is not considered a "great" vessel? a. Left anterior descending artery b. Aorta c. Venae cavae d. Pulmonary artery
Left anterior descending artery
Which of the following is part of the blood flow through the heart? a. Left atrium b. Left anterior descending artery c. Circumflex artery d. Right coronary artery
Left atrium
What is the hardest working cardiac chamber and therefore has the thickest myocardium? a. Right atrium b. Right ventricle c. Left atrium d. Left ventricle
Left ventricle
What is the significance of elevated plasma levels of AST, CPK, and LDH? a. Myocardial damage as in myocardial infarction b. A normal myocardial response to exercise c. An increase in coronary blood flow d. Early-onset exertional angina
Myocardial damage as in myocardial infarction
Which layer of the heart allows it to act as a pump? a. Epicardium b. Myocardium c. Pericardium d. Endocardium
Myocardium
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
Oxygen
Which of the following is descriptive of the vagus nerve? a. Fight-or-flight b. Parasympathetic c. Sympathetic d. Adrenergic
Parasympathetic
Which of the following electrical events is caused by the outflow (efflux) of K + ? a. P-R interval b. Depolarization c. QRS complex d. Repolarization
Repolarization
Which of the following is the same as end-diastolic volume? a. Stroke volume b. Cardiac output c. Preload d. Cardiac reserve
Preload
Which of the following structures "sees" unoxygenated blood? a. Aorta b. Left ventricle c. Pulmonary artery d. Pulmonary veins
Pulmonary artery
Which structure "sees" oxygenated blood? a. Tricuspid valve b. Pulmonary artery c. Pulmonary veins d. Right semilunar valve
Pulmonary veins
Which of the following is a function of a valve? a. Regulates the direction of the flow of blood through the heart b. Regulates the amount of oxygen bound to hemoglobin c. Regulates heart rate d. Directs the movement of the cardiac impulse
Regulates the direction of the flow of blood through the heart
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
Starling's law 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.
Starling's law of the heart.
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
Stroke volume
Which of the following defines a nodal rhythm? a. Sinus rhythm is normal. b. The electrical signal arises within the SA node. c. The electrical signal arises within the AV node. d. The ventricular myocardium is fibrillating.
The electrical signal arises within the AV node.
Which of the following best indicates why the left ventricular myocardium is thicker than the right ventricular myocardium? a. Left ventricular oxygen saturation is greater in the left ventricle. b. The left ventricle works harder than the right ventricle. c. The aortic valve is narrower than the pulmonic valve. d. Left ventricular volume is less than right ventricular volume.
The left ventricle works harder than the right ventricle.
Initially a child with a ventricular septal defect (VSD) and pulmonic valve stenosis is acyanotic. Over time, however, the pulmonic valve stenosis worsens and the child becomes cyanotic. What is the most probable explanation? a. The child becomes severely anemic and hypoxemic. b. The pulmonic stenosis elevates right ventricular pressure, thereby shunting unoxygenated blood from the right ventricle into the left ventricle; unoxygenated blood is then pumped to the systemic circulation. c. Blood is shunted from the left ventricle into the right ventricle. d. Excess blood in the right ventricle and pulmonary artery fills the alveoli, thereby causing hypoxemia and cyanosis.
The pulmonic stenosis elevates right ventricular pressure, thereby shunting unoxygenated blood from the right ventricle into the left ventricle; unoxygenated blood is then pumped to the systemic circulation.
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.
The ventricles are filling with blood.
Blood flows from the right atrium through which atrioventricular valve to the right ventricle? a. Bicuspid b. Mitral c. Pulmonic d. Tricuspid
Tricuspid
What is the name of the valve that prevents backflow of blood into the right atrium when the right ventricle contracts? a. Mitral b. Pulmonic c. Semilunar d. Tricuspid
Tricuspid
Which of the following is most apt to cause a (+) inotropic effect? a. Activation of the alpha 1 -adrenergic receptors by ACh b. Activation of the muscarinic receptors by NE c. Blockade of alpha 1 -adrenergic receptors d. Use of a beta 1 -adrenergic agonist
Use of a beta 1 -adrenergic agonist
Under what condition will the AV node become the pacemaker? a. When its rate of spontaneous depolarization exceeds that of the ventricular conduction cells b. As a normal response to sympathetic nerve discharge c. When its rate of spontaneous depolarization exceeds that of the SA node d. In the presence of normal sinus rhythm
When its rate of spontaneous depolarization exceeds that of the SA node
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. More than one of the above are true.
a. The ventricles are relaxed. c. The atria pump blood into the ventricles. d. More than one of the above are true.
A patient in heart failure is given a drug that is classified as a beta 1 -adrenergic agonist. The drug a. blocks the beta 1 -adrenergic receptors and causes a (-) chronotropic and (-) inotropic effect. b. activates the beta 1 -adrenergic receptors and causes bronchoconstriction. c. activates the beta 1 -adrenergic receptors and causes a (+) inotropic effect. d. activates the vagus nerve, thereby slowing heart rate and strengthening myocardial contraction.
activates the beta 1 -adrenergic receptors and causes a (+) inotropic effect.
The correct sequence is: Blood flows from the pulmonary capillaries to the pulmonary veins to the left atrium to the left ventricle to the a. vena cava. b. pulmonary artery. c. aorta. d. circle of Willis.
aorta
Venodilation a. increases afterload. b. decreases preload. c. increases end-diastolic volume. d. stretches the ventricular myocardium.
decreases preload.
The atrioventricular node (AV node) a. is the pacemaker of the heart. b. is located in the upper part of the right atrium. c. has a rate that is normally faster than the SA node. d. delays the electrical signal coming from the atria into the ventricles.
delays the electrical signal coming from the atria into the ventricles.
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.
increases afterload, thereby increasing the work of the left ventricle.
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.
increases heart rate
Atropine, a muscarinic blocker, a. increases heart rate. b. causes bradycardia. c. is also classified as sympathomimetic. d. is vagomimetic.
increases heart rate.
Sympathetic stimulation to the heart a. decreases stroke volume. b. increases heart rate. c. causes bradycardia. d. decreases cardiac output.
increases heart rate.
An increased preload a. decreases cardiac output. b. increases stroke volume. c. increases cardiac reserve. d. increases afterload.
increases stroke volume.
Increased return of the blood to the heart stretches the muscle, thereby a. stimulating the sympathetic nerve. b. activating the beta 1 -adrenergic receptors. c. closing the AV valves. d. increasing stroke volume.
increasing stroke volume.
