Cardiac output is __________.
A)the amount of blood filling each ventricle at the end of diastole
B)the amount of blood pumped out of the heart during every ventricular contraction
C)the number of impulses fired by the SA node in one minute
D)the amount of blood pumped out of each ventricle in one minute
E)the number of times the heart beats in one minute
D)the amount of blood pumped out of each ventricle in one minute
Choose the correct sequence of current flow through the heart wall.
A)AV node, Purkinje fibers, AV node, AV bundle, right and left bundle branches
B)SA node, AV node, AV bundle, right and left bundle branches, Purkinje fibers
C)AV node, SA node, Purkinje fibers, AV bundle, right and left bundle branches
D)SA node, Purkinje fibers, AV node, AV bundle, right and left bundle branches
E)Purkinje fibers, AV node, AV bundle, right and left bundle branches, SA node
B)SA node, AV node, AV bundle, right and left bundle branches, Purkinje fibers
During pulmonary circulation, blood leaves the __________.
A)right atrium and goes directly to the left ventricle
B)right ventricle and goes directly to the aorta
C)right ventricle and moves to the lungs
D)right atrium and goes directly to the lungs
E)left ventricle and moves to the lungs
C)right ventricle and moves to the lungs
During systemic circulation, blood leaves the __________.
A)right ventricle and moves to the lungs
B)right ventricle and goes directly to the aorta
C)right atrium and goes directly to the lungs
D)lungs and moves to the left atrium
E)left ventricle and goes directly to the aorta
B)right ventricle and goes directly to the aorta
Identify the correct sequence of blood flow through the chambers of the heart.
A)left ventricle, left atrium, lungs, right ventricle, right atrium
B)right ventricle, left ventricle, left atrium, lungs, right atrium
C)left atrium, left ventricle, right ventricle, right atrium, lungs
D)right atrium, right ventricle, lungs, left atrium, left ventricle
E)lungs, right ventricle, left ventricle, right atrium, left atrium
D)right atrium, right ventricle, lungs, left atrium, left ventricle
The absolute refractory period refers to the time during which __________.
A)a skeletal muscle cannot respond to any stimulus and lasts about 250 milliseconds
B)the muscle cell is ready to respond to a threshold stimulus
C)the muscle cell is not in a position to respond to a stimulus of any strength
D)the muscle cell is ready to respond to any stimulus
E)a cardiac muscle cannot respond to any stimulus and lasts only 1 to 2 milliseconds
C)the muscle cell is not in a position to respond to a stimulus of any strength
The cardiac cycle includes all of the following events EXCEPT __________.
A)the movement of impulse from the SA node to all regions of the heart wall
B)the closing and opening of the heart valves during each heartbeat
C)the changes in pressure gradients in all chambers of the heart
D)the number of times the heart beats in one minute
E)the changes in blood volume in all chambers of the heart
D)the number of times the heart beats in one minute
The coronary arteries arise from the __________.
A)right atrium
B)Pulmanary trunk
C)superior vena cava
D)aorta
E)inferior vena cava
D)aorta
The endocardium is composed of __________.
A)simple columnar epithelium
B)cardiac muscle cells
C)simple squamous epithelium
E)simple cuboidal epithelium
F)stratified squamous epithelium
C)simple squamous epithelium
The inferior vena cava brings blood from the lower regions of the body and empties into the __________.
A)right ventricle
B)left ventricle
C)left atrium
D)right atrium
E)aorta
D)right atrium
The inner lining of the fibrous pericardium is formed by the __________.
A)endocardium
B)myocardium
C)epicardium
D)parietal layer of serous pericardium
E)pericardial cavity
F)diaphragm
D)parietal layer of serous pericardium
The interventricular septum forms a dividing wall between the __________.
A)left atrium and left ventricle
B)right ventricle and left atrium
C)left atrium and right atrium
D)right atrium and right ventricle
E)left and right ventricles
E)left and right ventricles
The normal pacemaker of the heart is the __________.
A)the bundle branches
B)AV node
C)SA node
D)Purkinje fibers
E)AV bundle
C)SA node
The tricuspid valve is located between the __________.
A)right and left atria
B)left atrium and left ventricle
C)right and left ventricles
D)right ventricle and the aorta
E)right atrium and right ventricle
E)right atrium and right ventricle
When the mitral valve closes, it prevents the backflow of blood from the __________.
A)left ventricle into the aorta
B)left ventricle into the left atrium
C)right ventricle into the pulmonary trunk
D)left atrium into the left ventricle
E)right atrium into the right ventricle
B)left ventricle into the left atrium
Which is the correct sequence of layers in the heart wall, starting with the outer layer?
A)endocardium, epicardium, myocardium
B)endocardium, smooth muscle, epicardium
C)epicardium, myocardium, endocardium
D)myocardium, pericardium, endocardium
E)parietal pericardium, myocardium, endocardium
C)epicardium, myocardium, endocardium
Which of the following statements is NOT true about the shape, position, and location of the heart?
A)The heart is shaped like a cone with the base facing the right shoulder.
B)The heart is located between the two lungs within the mediastinum.
C)Approximately two-thirds of the heart is found to the left of the midline.
D)The heart is enclosed in a double-layered sac called the pleural membrane.
D)The heart is enclosed in a double-layered sac called the pleural membrane.
The vessels that carry oxygen to the myocardium are called __________.
A)coronary veins
B)pulmonary veins
C)coronary arteries
D)pulmonary arteries
E)aortic arteries
C)coronary arteries
The cells of the myocardium behave as a single, coordinated unit called a __________.
A)cardiac cycle
B)pacemaker
C)sarcomere
D)contractile unit
E)functional syncytium
E)functional syncytium
The ability of some cardiac muscle cells to initiate their own depolarization and cause depolarization of the rest of the heart is called __________.
A)automaticity
B)fibrillation
C)an action potential
E)a functional syncytium
F)the absolute refractory period
A)automaticity
Guided by powerful signaling molecules, the human heart develops from __________.
A)ectoderm
B)mesoderm
C)cardioderm
D)endoderm
B)mesoderm
Which of the following structures lies on the outside surface of the heart and is an integral part of the cardiac wall?
A)the fibrous pericardium
B)the epicardium
C)the pericardial sac
D)the parietal layer of serous pericardium
B)the epicardium
The trabeculae carneae are located in the __________.
A)atrium
B)endocardium
C)ventricles
D)epicardium
C)ventricles
What part of the heart is considered the systemic circuit pump?
A)the right ventricle
B)the left atrium
C)the left ventricle
D)the right atrium
C)the left ventricle
The __________ are attached to the AV valve flaps.
A)trabeculae carneae
B)pectinate muscles
C)chordae tendineae
D)papillary muscles
C)chordae tendineae
Which of the following valves is most often faulty in the heart?
A)the pulmonary semilunar valve
B)the tricuspid valve
C)the mitral, or bicuspid, valve
D)the aortic semilunar valve
C)the mitral, or bicuspid, valve
Which of the following factors gives the myocardium its high resistance to fatigue?
A)gap junctions
B)the coronary circulation
C)the presence of intercalated discs
D)a very large number of mitochondria in the cytoplasm
D)a very large number of mitochondria in the cytoplasm
The __________ nerve carries parasympathetic fibers to the sinoatrial (SA) node.
A)hypoglossal
B)vagus
C)facial
D)accessory
B)vagus
An enlarged R wave on an ECG would indicate __________.
A)cardiac ischemia
B)repolarization abnormalities
C)a myocardial infarction
D)an enlarged ventricle
D)an enlarged ventricle
A doctor puts his stethoscope on a patient's chest over the location of the heart and hears a swishing sound. Which of the following conditions is the best diagnosis for the patient's condition?
A)incompetent cardiac valve
B)myocardial infarction
C)angina pectoris
D)cardiac tamponade
A)incompetent cardiac valve
Which of the following is NOT a role of the pericardium?
A)It protects the heart.
B)It anchors the heart to surrounding structures.
C)It prevents the heart from overfilling with blood.
D)It facilitates heart contraction.
D)It facilitates heart contraction.
The lining of the heart chambers is called the __________.
A)myocardium
B)epicardium
C)endocardium
D)pericardium
C)endocardium
The superior chambers of the heart are called the __________.
A)atria
B)ventricles
C)cavea
D)coronary chambers
A)atria
Freshly oxygenated blood is delivered to the __________ and then it passes into the __________ to be pumped to the entire body.
A)right ventricle; right atrium
B)right atrium; right ventricle
C)left ventricle; left atrium
D)left atrium; left ventricle
D)left atrium; left ventricle
Into which chamber of the heart do the pulmonary veins deliver blood?
A)right ventricle
B)right atrium
C)left ventricle
D)left atrium
D)left atrium
right marginal artery
A)supplies blood to the left atrium and posterior walls of the left ventricle
B)supplies blood to the interventricular septum and anterior walls of both ventricles
C)supplies blood to the lateral right side of the myocardium
D)runs to the apex of the heart
C)supplies blood to the lateral right side of the myocardium
posterior interventricular artery
A)supplies blood to the left atrium and posterior walls of the left ventricle
B)supplies blood to the interventricular septum and anterior walls of both ventricles
C)supplies blood to the lateral right side of the myocardium
D)runs to the apex of the heart
D)runs to the apex of the heart
anterior interventricular artery
A)supplies blood to the left atrium and posterior walls of the left ventricle
B)supplies blood to the interventricular septum and anterior walls of both ventricles
C)supplies blood to the lateral right side of the myocardium
D)runs to the apex of the heart
B)supplies blood to the interventricular septum and anterior walls of both ventricles
circumflex artery
A)supplies blood to the left atrium and posterior walls of the left ventricle
B)supplies blood to the interventricular septum and anterior walls of both ventricles
C)supplies blood to the lateral right side of the myocardium
D)runs to the apex of the heart
A)supplies blood to the left atrium and posterior walls of the left ventricle
The most muscular chamber of the heart is the __________.
A)left atrium
B)right atrium
C)right ventricle
D)left ventricle
D)left ventricle
tricuspid valve
A)prevents backflow of blood into the left ventricle
B)valve between the right atrium and right ventricle
C)prevents backflow of blood into the right ventricle
D)valve between the left atrium and left ventricle
B)valve between the right atrium and right ventricle
mitral valve
A)prevents backflow of blood into the left ventricle
B)valve between the right atrium and right ventricle
C)prevents backflow of blood into the right ventricle
D)valve between the left atrium and left ventricle
D)valve between the left atrium and left ventricle
aortic semilunar valve
A)prevents backflow of blood into the left ventricle
B)valve between the right atrium and right ventricle
C)prevents backflow of blood into the right ventricle
D)valve between the left atrium and left ventricle
A)prevents backflow of blood into the left ventricle
pulmonary semilunar valve
A)prevents backflow of blood into the left ventricle
B)valve between the right atrium and right ventricle
C)prevents backflow of blood into the right ventricle
D)valve between the left atrium and left ventricle
C)prevents backflow of blood into the right ventricle
Which of the following is a difference between cardiac muscle and skeletal muscle?
A)Unlike skeletal muscle cells, cardiac muscle cells can be autorhythmic.
B)Unlike skeletal muscle, cardiac muscle is not striated.
C)Unlike skeletal muscle cells, cardiac muscle cells do not rely on an influx of calcium ions for depolarization.
D)Unlike skeletal muscle, cardiac muscle does not use a sliding filament mechanism for contraction.
A)Unlike skeletal muscle cells, cardiac muscle cells can be autorhythmic
The role of the atrioventricular node (AV node) is to __________.
A)slow down impulses so that the atria can contract to fill the adjacent ventricles with blood
B)initiate a sinus rhythm
C)conduct impulses to the sinoatrial node (SA node)
D)initiate ventricular depolarization
B)initiate a sinus rhythm
Which is correctly paired?
A)heart block: uncoordinated atrial and ventricular contraction
B)arrhythmia: AV node failure
C)fibrillation: premature contraction
D)ectopic focus: an abnormal pacemaker
D)ectopic focus: an abnormal pacemaker
The P wave of an electrocardiogram represents __________.
A)atrial repolarization
B)ventricular repolarization
C)atrial depolarization
D)ventricular depolarization
C)atrial depolarization
The second heart sound (the 'dup' of 'lub-dup') is caused by the __________.
A)opening of the semilunar valves
B)closure of the atrioventricular valves
C)opening of the atrioventricular valves
D)closure of the semilunar valves
D)closure of the semilunar valves
cardiac cycle
A)contraction
B)relaxation
C)the volume of blood pumped by one ventricle with each heartbeat
D)the amount of blood pumped by each ventricle in one minute
E)the events associated with blood flow through the heart during one complete heartbeat
E)the events associated with blood flow through the heart during one complete heartbeat
systole
A)contraction
B)relaxation
C)the volume of blood pumped by one ventricle with each heartbeat
D)the amount of blood pumped by each ventricle in one minute
E)the events associated with blood flow through the heart during one complete heartbeat
A)contraction
diastole
A)contraction
B)relaxation
C)the volume of blood pumped by one ventricle with each heartbeat
D)the amount of blood pumped by each ventricle in one minute
E)the events associated with blood flow through the heart during one complete heartbeat
B)relaxation
stroke volume
A)contraction
B)relaxation
C)the volume of blood pumped by one ventricle with each heartbeat
D)the amount of blood pumped by each ventricle in one minute
E)the events associated with blood flow through the heart during one complete heartbeat
C)the volume of blood pumped by one ventricle with each heartbeat
cardiac output
A)contraction
B)relaxation
C)the volume of blood pumped by one ventricle with each heartbeat
D)the amount of blood pumped by each ventricle in one minute
E)the events associated with blood flow through the heart during one complete heartbeat
D)the amount of blood pumped by each ventricle in one minute
Which of the following would lead to a decrease in heart rate?
A)norepinephrine
B)exercise
C)parasympathetic stimulation
D)sharply decreased blood volume
C)parasympathetic stimulation
True or False
In the fetus, blood from the left and right sides of the heart normally mix.
True