McGraw Hill: Heart: Practice
Arrange these components of the heart's conduction system in their sequence of activity, beginning with the pacemaker: (1) Purkinje fibers (2) AV node (3) SA node (4) AV bundle A) 3, 2, 4, 1 B) 2, 3, 1, 4 C) 4, 2, 1, 3 D) 1, 3, 2, 4
A) 3, 2, 4, 1
Which of the following is the correct circulatory sequence for blood to pass through part of the heart? A) R. atrium --> right AV valve --> R. ventricle --> pulmonary semilunar valve. B) R. atrium --> left AV valve --> R. ventricle --> pulmonary semilunar valve. C) L. atrium --> right AV valve --> L. ventricle --> aortic semilunar valve. D) L. atrium --> left AV valve --> L. ventricle --> pulmonary semilunar valve.
A) R. atrium --> right AV valve --> R. ventricle --> pulmonary semilunar valve.
Oxygenated blood flows through ____________ in the systemic circuit but through ____________ and the opposite heart chambers in the pulmonary circuit. A) arteries and the left atrium and ventricle; veins B) arteries and the right atrium and ventricle; veins C) veins and the left atrium and ventricle; arteries D) veins and the right atrium and ventricle; arteries
A) arteries and the left atrium and ventricle; veins
Which set correctly lists the sequence in which events in the cardiac cycle begin? A) atrial systole, atrial diastole, ventricular systole, ventricular diastole B) atrial systole, ventricular systole, atrial diastole, ventricular diastole C) ventricular systole, atrial systole, ventricular diastole, atrial diastole D) ventricular systole, ventricular diastole, atrial diastole, atrial systole
A) atrial systole, atrial diastole, ventricular systole, ventricular diastole
What happens during ventricular diastole? A) both ventricles fill with blood B) both semilunar valves remain open C) both AV valves remain closed D) both ventricles contract
A) both ventricles fill with blood
An ECG produces a composite tracing of all ____________ generated by myocardial cells. A) muscle impulses B) nerve impulses C) muscle contractions D) metabolic activity
A) muscle impulses
Which potentially fatal heart problem is most like a stroke, or cerebrovascular accident? A) myocardial infarction B) ventricular fibrillation C) cardiac arrest D) cardiac tamponade
A) myocardial infarction
What are the prominent ridges on the internal surfaces of the auricles and the anterior atrial walls? A) pectinate muscles B) papillary muscles C) trabeculae carneae D) chordae tendineae
A) pectinate muscles
Blood from the systemic circuit returns directly into which heart chamber? A) right atrium B) left atrium C) right auricle D) left auricle
A) right atrium
The heart is rotated such that the ____________ are located more anteriorly, while the other chambers are located more posteriorly. A) right atrium and ventricle B) left atrium and ventricle C) right and left atria D) right and left ventricles
A) right atrium and ventricle
In the developing heart, the atria form from the primitive atrium and the A) sinus venosus. B) bulbus cordis. C) primitive ventricle. D) conus cordis.
A) sinus venosus.
The ____________ carries blood throughout the body; the ____________ carries blood only to and from the lungs. A) systemic circuit; pulmonary circuit B) pulmonary circuit; systemic circuit C) venous circulation; arterial circulation D) arterial circulation; venous circulation
A) systemic circuit; pulmonary circuit
As their name implies, the heart chambers that receive blood returning through both circulatory circuits are called A) auricles B) atria C) ventricles D) sinuses
B) atria
The myocardium is composed of A) an outer fibrous layer and an inner serous layer B) cardiac muscle tissue C) a simple squamous epithelium and a layer of areolar connective tissue D) both b and c
B) cardiac muscle tissue
Which structures prevent the AV valves from everting and flipping into the atria when the ventricles contract? A) chordae tendineae and pectinate muscles B) chordae tendineae and papillary muscles C) conus arteriosus and interventricular septum D) foramen ovale and fossa ovalis
B) chordae tendineae and papillary muscles
Venous blood from the heart wall enters the right atrium through the A) superior vena cava. B) coronary sinus. C) inferior vena cava. D) pulmonary veins.
B) coronary sinus.
Externally, the atria and ventricles are separated by a relatively deep groove called the A) interventricular sulcus B) coronary sulcus C) interatrial sulcus D) atrioventricular septum
B) coronary sulcus
The serous pericardium does not A) facilitate almost frictionless movement as the heart beats B) form a mucous membrane lining the pericardial cavity C) consist of an outer parietal layer and an inner visceral layer D) secrete a lubricating fluid into the pericardial cavity
B) form a mucous membrane lining the pericardial cavity
After birth, the foramen ovale of the fetal heart is replaced by a small depression in the interatrial septum called the A) ligamentum arteriosum B) fossa ovalis C) conus cordis D) truncus arteriosus D) truncus arteriosus
B) fossa ovalis
Muscle impulses are spread rapidly between cardiac muscle fibers by A) sarcomeres. B) intercalated discs. C) chemical neurotransmitters. D) AV valves.
B) intercalated discs.
Tachycardia predisposes a person to inadequate coronary blood flow because A) it lowers blood pressure, reducing the "push" of blood through the myocardium B) it reduces the time that the myocardium is relaxed enough to permit blood flow C) it raises blood pressure, forcing blood too quickly past the coronary arteries D) it shortens systole, when blood would normally be squeezed through the myocardium
B) it reduces the time that the myocardium is relaxed enough to permit blood flow
When closed, the left atrioventricular valve prevents backflow of blood into the A) left ventricle B) left atrium C) right atrium D) right ventricle
B) left atrium
The pericardial cavity is located between the A) fibrous pericardium and the parietal layer of the serous pericardium. B) parietal and visceral layers of the serous pericardium. C) visceral layer of the serous pericardium and the epicardium. D) myocardium and the visceral layer of the serous pericardium.
B) parietal and visceral layers of the serous pericardium.
When a person's heart "skips a beat," what has most likely occurred? A) ventricular fibrillation B) premature ventricular contraction C) atrial flutter or fibrillation D) angina pectoris
B) premature ventricular contraction
What heart problem may be caused, ironically, by the body's attempt to protect itself from a streptococcal throat infection? A) cardiomyopathy B) rheumatic heart disease C) coronary atherosclerosis D) infectious endocarditis
B) rheumatic heart disease
The cardiac muscle fibers of the ____________ act as the pacemaker, the rhythmic center that initiates the heartbeat. A) AV node B) sinoatrial node C) atrioventricular bundle D) ventricular myocardium
B) sinoatrial node
Regardless of the heart chamber, contraction is called ____________ and relaxation, ____________. A) diastole, systole B) systole, diastole C) fibrillation, defibrillation D) defibrillation, fibrillation
B) systole, diastole
What would happen if the papillary muscles could not contract? A) the ventricular myocardium would also fail to contract B) the atrioventricular valves would not seal tightly C) blood would not enter the ventricles during diastole D) the semilunar valves would stay open throughout the cardiac cycle
B) the atrioventricular valves would not seal tightly
A type of heart murmur called mitral valve prolapse would most likely involve a defect in A) the size or shape of the right atrioventricular opening B) the left chordae tendineae or papillary muscles C) one of the three cusps of the tricuspid valve D) the structure of either semilunar valve
B) the left chordae tendineae or papillary muscles
Oxygenated blood returning from the lungs enters the left atrium through A) the pulmonary arteries B) the pulmonary veins C) the coronary sinus D) all of the above
B) the pulmonary veins
The irregular muscular ridges in the ventricular walls are the A) papillary muscles. B) trabeculae carneae. C) chordae tendineae. D) moderator bands.
B) trabeculae carneae.
What ensures the unidirectional flow of blood through both the heart and the blood vessels? A) constant pressure generated by the heart contractions B) valves within the heart that prevent backflow of blood C) squeezing action of smooth muscle tissue in arterial walls D) continuous osmotic outflow of plasma from capillaries
B) valves within the heart that prevent backflow of blood
Rank the following in order from the longest lasting to the shortest-lived condition in a normal cardiac cycle: (1) atria relaxed (2) ventricles contracting (3) AV valves open (4) semilunar valves closed A) 3, 2, 4, 1 B) 2, 4, 1, 3 C) 1, 4, 3, 2 D) 4, 1, 2, 3
C) 1, 4, 3, 2
If the fetal septum primum and septum secundum fail to fuse properly at birth, the newborn has a congenital heart malformation called A) pulmonary stenosis B) tetralogy of Fallot C) an atrial septal defect D) a ventricular septal defect
C) an atrial septal defect
The inferior, conical end of the heart is called the A) base B) inferior angle C) apex D) right ventricle
C) apex
When the ventricles contract, all of the following occur except A) closing of the AV valves. B) blood ejecting into the pulmonary trunk and aorta. C) closing of the semilunar valves. D) opening of the semilunar valves.
C) closing of the semilunar valves
Specialized cardiac muscle fibers that transmit muscle impulses to the contractile muscle cells of the myocardium are an important part of the heart's A) fibrous skeleton B) valvular apparatus C) conduction system D) all of the above
C) conduction system
Just before leaving the heart to go to the lungs, blood must pass through a smooth-walled region called the A) bulbus cordis B) sinus venosus C) conus arteriosus D) pulmonary trunk
C) conus arteriosus
Sympathetic and parasympathetic components of the autonomic nervous system that innervate the heart are collectively called the A) bundle of His B) cardiac nerves C) coronary plexus D) Purkinje fibers
C) coronary plexus
In the coronary circulation, all venous blood returns to the heart through the A) great cardiac vein B) middle cardiac vein C) coronary sinus D) all of the above
C) coronary sinus
The QRS complex of a typical electrocardiogram (ECG) tracing denotes the beginning of A) depolarization of the atria B) repolarization of the atria C) depolarization of the ventricles D) repolarization of the ventricles
C) depolarization of the ventricles
In an ECG tracing, what might an unusually strong QRS complex indicate? A) damage to the sinoatrial node B) acute coronary ischemia C) hypertrophy of the ventricular myocardium D) damage to the AV bundle or Purkinje fibers
C) hypertrophy of the ventricular myocardium
The thickest part of the heart wall is the A) pericardium. B) epicardium. C) myocardium. D) endocardium.
C) myocardium.
The fibrous skeleton of the heart does not A) separate the atria and ventricles B) anchor and stabilize the heart valves C) promote random impulse conduction throughout the heart wall D) provide a rigid framework for the attachment of cardiac muscle tissue
C) promote random impulse conduction throughout the heart wall
From the right atrium, blood passes through the right AV (tricuspid) valve into the A) pulmonary trunk B) left atrium C) right ventricle D) left ventricle
C) right ventricle
Under normal conditions, only two heart chambers are ever concurrently in ____________, but all four are ____________ together for the last half of the cardiac cycle. A) diastole; relaxing B) systole; contracting C) systole; relaxing D) diastole; contracting
C) systole; relaxing
In terms of oxygen content of the blood they transmit, left atrioventricular is to aortic semilunar as ____________ is to pulmonary semilunar. A) mitral B) bicuspid C) tricuspid D) none of the above
C) tricuspid
The epicardium is also called the A) fibrous pericardium B) serous pericardium C) visceral layer of the serous pericardium D) parietal layer of the serous pericardium
C) visceral layer of the serous pericardium
Sympathetic innervation of cardiac muscle originates from A) CN X (vagus nerve). B) L1-L2 segments of the spinal cord. C) the AV node. D) T1-T5 segments of the spinal cord.
D) T1-T5 segments of the spinal cord.
The inclusive period of time from the beginning of one heartbeat to the next is called A) systole B) diastole C) a conduction pattern D) a cardiac cycle
D) a cardiac cycle
Blood from the systemic circuit returns to the right atrium through A) the superior vena cava B) the inferior vena cava C) the coronary sinus D) all of the above
D) all of the above
In which of the following pairs do the events start almost simultaneously? A) ventricular systole, first heart sound ("lubb") B) atrial diastole, ventricular systole C) ventricular diastole, closing of semilunar valves D) all of the above
D) all of the above
In which of the following ways does cardiac muscle tissue differ from skeletal muscle tissue? A) cardiac muscle fibers are relatively short and branched or bifurcated B) neighboring cardiac muscle fibers are connected by intercalated discs C) each cardiac muscle cell has only one or two centrally located nuclei D) all of the above
D) all of the above
The left and right coronary arteries A) are functional end arteries despite sharing tiny anastomoses B) are the only branches from the ascending aorta C) have highly variable distribution in the posterior ventricular walls D) all of the above
D) all of the above
What causes a heart murmur? A) valvular leakage B) decreased valve flexibility C) a misshapen valve D) any of the above
D) any of the above
Autonomic innervation of the heart does which of the following? A) initiates heartbeat at beginning of each cardiac cycle B) increases heart rate and force of contractions C) decreases heart rate without changing force of contractions D) both b and c
D) both b and c
As the ventricles start to contract, the first heart sound ("lubb") signifies the A) opening of all four heart valves B) closing of all four heart valves C) closing of the semilunar valves D) closing of the AV valves
D) closing of the AV valves
How is blood prevented from flowing into the right ventricle from the pulmonary trunk? A) closing of the right AV valves B) opening of the pulmonary semilunar valve C) contraction of the right atrium D) closing of the semilunar valve
D) closing of the semilunar valve
What are the three layers of the heart wall, in order from external to internal? A) pericardium, myocardium, epicardium B) endocardium, myocardium, pericardium C) myocardium, endocardium, epicardium D) epicardium, myocardium, endocardium
D) epicardium, myocardium, endocardium
All of the following are true of the left ventricle except A) wall is typically 3 times thicker than that of right ventricle B) inner wall contains prominent trabeculae carneae and papillary muscles C) aortic semilunar valve at superior end separates it from the aorta D) receives deoxygenated venous blood from the left atrium
D) receives deoxygenated venous blood from the left atrium
The pulmonary trunk carries blood from which heart chamber into the pulmonary circuit? A) left atrium B) right atrium C) left ventricle D) right ventricle
D) right ventricle
All of the following accurately characterize heart development except A) two heart tubes fuse to form a single primitive heart tube by day 21 B) four expansions that give rise to postnatal heart structures develop by day 22 C) the heart tube becomes partitioned into four chambers during weeks 5-8 D) the heart starts beating as soon as development is complete, by week 8
D) the heart starts beating as soon as development is complete, by week 8
Which of the following is not true of a normal adult heart? A) both atria receive only venous blood B) both ventricles discharge blood only into arteries C) the two left chambers conduct only oxygenated blood D) the left ventricle pumps at a faster rate than the right
D) the left ventricle pumps at a faster rate than the right