Chp 20 Study Quesions
Which valve prevents backflow of blood from the right ventricle into the right atrium
B
Which diagnostic procedure for CAD is used to visualize coronary blood vessels?
Coronary angiography is used to visualize many blood vessels.
Baroreceptors monitor changes in blood chemistry.
False
During fetal development, an opening called the foramen ovale allows blood in the right and left ventricles to mix.
False
Oxygenated blood is found in the right ventricle. True False
False
The coronary artery carries blood to the right atrium.
False
The interventricular septum separates the ventricles from the atria.
False
The left ventricular pressure must be greater than the aortic pressure during ventricular ejection so that blood will move out through the pulmonary arteries.
False
Which patients are candidates for cardiac transplantation?
Individuals with end‐stage heart failure or severe coronary artery disease are candidates for cardiac transplantation.
During repolarization of a cardiac muscle fiber Na+ moves out of the cell both Na+ and K+ move into the cell K+ moves out of the cell K+ moves into the cell
K+ moves out of the cell
Embryologically, the heart is a derivative of the
Mesoderm
From which tissue does the heart develop?
Mesoderm
Would more blood flow through the heart during ventricular systole or ventricular diastole? More blood would flow during ventricular systole because the ventricles are relaxed and the vessels are open. More blood would flow during ventricular diastole because the vessels are open. More blood would flow through during ventricular diastole because the vessels are squeezed shut. Blood flow is equal during ventricular systole and ventricular diastole.
More blood would flow during ventricular diastole because the vessels are open.
Which numbers constitute the pulmonary circulation? Which constitute the systemic circulation?
Numbers 2 (right ventricle) through 6 (left atrium) depict the pulmonary circulation; numbers 7 (left ventricle) through 1 (right atrium) depict the systemic circulation.
When is the partitioning of the heart complete?
Partitioning of the heart is complete by the end of the fifth week.
Which structure is the pacemaker of the heart?
SA node
Which of the following statements is incorrect? Cardiac muscle fibers are shorter in length than skeletal muscle fibers. Skeletal muscle fibers are more branched than cardiac muscle fibers. Most cardiac muscle fibers are uninucleate. Cardiac muscle fibers are connected by intercalated disks. Mitochondria are larger and more numerous in cardiac muscle fibers.
Skeletal muscle fibers are more branched than cardiac muscle fibers
Which of the following statements is correct? The auricles are extensions of the ventricles which serve to increase the ventricular volume. The coronary sulcus marks the boundary between the two ventricles. Sulci contain coronary blood vessels. Trabeculae carneae are muscular ridges on the interior wall of the right atrium
Sulci contain coronary blood vessels.
Which heart sound is related to blood turbulence associated with closure of the atrioventricular valves?
The first heart sound (S1), or lubb, is associated with closure of the atrioventricular valves.
When during embryonic development does the primitive heart begin to contract?
The heart begins to contract by the twenty‐second day of gestation.
What region of the heart is innervated by the sympathetic division but not by the parasympathetic division?
The ventricular myocardium receives innervation from the sympathetic division only.
he left anterior descending artery supplies blood to: The atrial walls The walls of both ventricles The left ventricle and left atrium Right atrium Left atrium
The walls of both ventricles
Cardiac output is the volume of blood ejected from the left ventricle into the aorta each minute.
True
Chordae tendineae stabilize the bicuspid valve and prevent it from prolapsing. True False
True
The cardiovascular system is one of the first to develop because the rapidly growing embryo needs to obtain oxygen and nutrients and get rid of waste products.
True
The fibrous skeleton of the heart consists of four dense connective tissue rings surrounding the valves of the heart.
True
Why is ventricular fibrillation such a serious arrhythmia?
Ventricular fibrillation is such a serious arrhythmia because ventricular pumping stops, blood ejection ceases, and circulatory failure and death can occur without immediate medical intervention.
What does A represent? closed ductus arteriosus opening between aorta and pulmonary trunk bypass connecting both atria valve between aorta and pulmonary trunk
closed ductus arteriosus
The sinoatrial node contains autorhythmic fibers that repeatedly generate action potentials is connected to the AV node by way of Purkinje fibers transmits impulses directly to the ventricular myocardium is another name for the atrioventricular node
contains autorhythmic fibers that repeatedly generate action potentials
Which of the following is NOT a congenital heart defect coarctation of the aorta coronary artery disease atrial septal defect tetralogy of Fallot patent ductus arteriosus
coronary artery disease
Positive inotropic agents
increase contractility of the heart
During exercise, increased muscle contraction helps return more blood to the heart. This would lead to
increased stroke volume
The plateau phase of the action potential in cardiac muscle is due to outflow of Ca2+ outflow of Na+ inflow of Ca2+ inflow of K+
inflow of Ca2+
Internally, the right and left halves of the heart are separated by the pulmonary semilunar valve atrioventricular valve papillary muscles interatrial and interventricular septa
interatrial and interventricular septa
The atrioventricular (AV) bundle (bundle of His) is composed of Purkinje fibers is the only site where action potentials can conduct from the atria to the ventricles. contains fibers that hold the atrioventricular valves closed during systole is located in the coronary sinus
is the only site where action potentials can conduct from the atria to the ventricles
Why is the left ventricle wall thicker than the right? left ventricle delivers blood to the systemic circulation left ventricle delivers blood to the pulmonary circulation left ventricle delivers more blood than the right to the arteries left ventricle blood more quickly to the arteries than does the right
left ventricle delivers blood to the systemic circulation
Nervous regulation of the heart originates in the
medulla oblongata
Release of norepinephrine from nerve fibers causes
ncreased heart rate and force of contraction
What is the function of B stabilize the ventricle during contraction open and close the valves close the valve prevent valve cusps from everting
prevent valve cusps from everting
The closing of the semilunar valves
produces the second heart sound
When the left ventricle fails, blood backs up in the lungs, causing
pulmonary edema
Tachycardia refers to
rapid heart rate
Which of the following is a risk factor for developing coronary artery disease? getting 20 minutes of aerobic exercise three times a week maintaining a weight proportionate to your height not smoking sedentary life style having high HDL levels and low LDL levels
sedentary life style
The Frank-Starling law of the heart states that
the volume of blood that enters the heart during diastole directly affects the force of contraction at systole
Most of the heart lies to the left of midline of the thoracic cavity to the right of midline of the thoracic cavity with the base directed to the left with apex pointing to the right
to the left of midline of the thoracic cavity
The ridges formed by raised bundles of cardiac muscle fibers on the internal surface of the ventricles are called the desmosomes trabeculae carneae fossa ovalis ligamentum arteriosum
trabeculae carneae
Ventricular systole is caused by atrial depolarization atrial repolarization ventricular depolarization ventricular repolarization
ventricular depolarization
What event occurs after B? ventricular depolarization ventricular contraction atrial contraction atrial repolarization
ventricular depolarization
Asynchronous, haphazard, ventricular contractions are characteristic of
ventricular fibrillation
When the ventricles relax
ventricular pressure drops
T wave on an EKG is due to atrial depolarization ventricular depolarization atrial repolarization ventricular repolarization
ventricular repolarization
The outer layer of the heart, called the epicardium, is also the visceral layer of the pericardium parietal layer of the pericardium fibrous pericardium muscular wall of the heart
visceral layer of the pericardium
What is the function of structure A?
...
During which two periods of the cardiac cycle do the heart muscle fibers exhibit isometric contraction? 1. Atrial contraction 2. Isovolumetric contraction 3. Ventricular ejection 4. Isovolumetric relaxation 5. Ventricular filling
2. Isovolumetric contraction 4. Isovolumetric relaxation
What is the cardiac output of a patient with a stroke volume of 70 mL/ventricular contraction whose heart rate is 90 beats/minute?
6300 mL/minute
Which of the following statements is INCORRECT? Cardiac reserve is the difference between a person's maximum cardiac output and cardiac output at rest. An average cardiac reserve is 4 to 5 times resting value. A top endurance athlete could have a cardiac reserve half their resting cardiac output. People with severe heart disease have little or no cardiac reserve.
A top endurance athlete could have a cardiac reserve half their resting cardiac output.
Where in the conduction system do action potentials propagate most slowly?
Action potentials propagate most slowly through the AV node.
Autorhythmic fibers: Are self excitable Are pacemakers Form the conduction system of the heart. All of these are correct
All of these are correct
Which of the following statements is/are correct Valves open and close in response to pressure changes The chordae tendineae and papillary muscles stop the atrioventricular valves from everting in response to high ventricular pressure. The atrioventricular valves are closed by filling of cusps by backflow of blood. All of these statements are correct.
All of these statements are correct.
Which of the following statements is/are incorrect? Intra-aortic balloon pump improves coronary blood flow and blood flow to peripheral tissues by inflating a balloon and deflating a balloon between heartbeats. Ventricular assist device uses a pump to aid a weakened ventricle in pumping blood. Cardiomyoplasty wraps the patient's skeletal muscle (usually the left latissimus dorsi ) around the heart and uses a pacemaker to stimulate the skeletal muscle to contract in synchrony with some of the heart beats.
All of these statements are correct.
What is the significance of an enlarged Q wave?
An enlarged Q wave may indicate a myocardial infarction (heart attack).
The left ventricle refills with blood in preparation for initiation of the next cardiac cycle during ventricular
Diastole
Which of the following statements is INCORRECT concerning contractile fibers? When a contractile fiber reaches threshold, voltage -gated fast sodium channels open allowing a rapid influx of sodium which produces a rapid depolarization which ends after several milliseconds. During plateau, depolarization is maintained because potassium inflow balances sodium outflow. Repolarization involves outflow of potassium restores the resting membrane potential to -90mV. During the refractory period a second contraction cannot be triggered.
During plateau, depolarization is maintained because potassium inflow balances sodium outflow.
A heart transplant usually involves removing all of the damaged heart except for the posterior wall of the right atrium.
False
Blood enters the systemic circuit of blood flow by passing through the pulmonary valve
False
Blood pressure is highest in the aorta during ventricular diastole.
False
Bradycardia is a condition in which the resting heart rate is greater than 80 beats per minute.
False
Cardiac muscle fibers produce much of their energy by way of anaerobic respiration.
False
The left ventricle is not as thick as the right ventricle since the right ventricle pumps blood throughout the body.
False
Stroke volume is regulated by:
Preload Contractility of the individual ventricular muscle fibers Afterload or the pressure that must be exceeded before ejection of blood from the ventricles can occur.
Which of the following is the correct pathway for passage of a drop of blood through the heart Right atrium, tricuspid valve, right ventricle, pulmonary semilunar valve, pulmonary artery, lungs, pulmonary veins, left atrium, bicuspid valve, left ventricle, aortic semilunar valve. Right atrium, tricuspid valve, right ventricle, pulmonary semilunar valve, pulmonary veins, lungs, pulmonary artery, left atrium, bicuspid valve, left ventricle, aortic semilunar valve. Right atrium, bicuspid valve, right ventricle, pulmonary semilunar valve, pulmonary artery, lungs, pulmonary veins, left atrium, tricuspid valve, left ventricle, aortic semilunar valve. Right atrium, tricuspid valve, right ventricle, pulmonary semilunar valve, pulmonary artery, lungs, pulmonary veins, left atrium, bicuspid valve, left ventricle, pulmonary semilunar valve.
Right atrium, tricuspid valve, right ventricle, pulmonary semilunar valve, pulmonary artery, lungs, pulmonary veins, left atrium, bicuspid valve, left ventricle, aortic semilunar valve.
Which of the following statements is/are incorrect? S1, the first heart sound, is associated with blood turbulence associated with closure of the atrioventricular valves at the beginning of ventricular diastole. S2, the second heart sound, is associated with blood turbulence associated with closure of the semilunar valves at the beginning of ventricular diastole. S3, the third heart sound, is due to blood turbulence during rapid atrial filling. S4, the fourth heart sound is due to blood turbulence during atrial systole.
S3, the third heart sound, is due to blood turbulence during rapid atrial filling.
Which of the following represents the correct sequence of flow of an electrical impulse through the heart? AV node, AV bundle, Purkinje fibers, SA node SA node, Purkinje fibers, AV node, AV bundle SA node, AV node, AV bundle, Purkinje fibers AV node, SA node, Purkinje fibers, AV bundle
SA node, AV node, AV bundle, Purkinje fibers
Which of the following statements about an ECG is incorrect? The P wave represents atrial depolarization. the QRS complex represents ventricular depolarization. The T wave represents ventricular repolarization. The P-Q interval represents the conduction time from the start of atrial excitation to the beginning of ventricular excitation. The S-T segment represents the time when ventricular contractile fibers are depolarized during the repolarization phase of the action potential.
The S-T segment represents the time when ventricular contractile fibers are depolarized during the repolarization phase of the action potential.
How much blood remains in each ventricle at the end of ventricular diastole in a resting person? What is this volume called?
The amount of blood in each ventricle at the end of ventricular diastole—called the end‐diastolic volume—is about 130 mL in a resting person.
Which coronary blood vessel delivers oxygenated blood to the walls of the left atrium and left ventricle?
The circumflex artery delivers oxygenated blood to the left atrium and left ventricle.
Which of the following statements is incorrect? The coronary sinus empties into the left atrium. Portions of the interior wall of the right atrium have pectinate muscles while the walls of the left atrium are smooth. The left atrium receives blood from 4 pulmonary veins. The left and right ventricles contain chordae tendineae and trabeculae carneae.
The coronary sinus empties into the left atrium.
The coronary sulcus forms an external boundary between which chambers of the heart?
The coronary sulcus forms a boundary between the atria and ventricles.
How does the duration of an action potential in a ventricular contractile fiber compare with that in a skeletal muscle fiber?
The duration of an action potential is much longer in a ventricular contractile fiber (0.3 sec = 300 msec) than in a skeletal muscle fiber (1-2 msec).
In what two ways does the fibrous skeleton contribute to the functioning of heart valves?
The fibrous skeleton attaches to the heart valves and prevents overstretching of the valves as blood passes through them.
How does thickness of the myocardium relate to the workload of a cardiac chamber?
The greater the workload of a heart chamber, the thicker its myocardium.
What are the functions of intercalated discs in cardiac muscle fibers?
The intercalated discs hold the cardiac muscle fibers together and enable action potentials to propagate from one muscle fiber to another.
What is the mediastinum?
The mediastinum is the anatomical region that extends from the sternum to the vertebral column, from the first rib to the diaphragm, and between the lungs.
Which component of the conduction system provides the only electrical connection between the atria and the ventricles?
The only electrical connection between the atria and the ventricles is the atrioventricular bundle.
How do papillary muscles prevent atrioventricular valve cusps from everting (swinging upward) into the atria?
The papillary muscles contract, which pulls on the chordae tendineae and prevents cusps of the atrioventricular valves from everting and letting blood flow back into the atria.
When you are exercising, contraction of skeletal muscles helps return blood to the heart more rapidly. Would this tend to increase or decrease stroke volume?
The skeletal muscle "pump" increases stroke volume by increasing preload (end‐diastolic volume).
Which layer is both a part of the pericardium and a part of the heart wall?
The visceral layer of the serous pericardium (epicardium) is both a part of the pericardium and a part of the heart wall.
Blood flows from the right atrium to the right ventricle through the _____ valve. tricuspid aortic semilunar pulmonary semilunar bicuspid
Tricuspid
An ECG is helpful in determining if the cardiac conduction path is abnormal, if the heart is enlarged, if certain regions of the heart are damaged, or the cause of chest pain.
True
Cardiac output equals the stroke volume multiplied by the heart rate.
True
Gap junctions in the intercalated disks allow action potentials to pass from one cardiac muscle cell to another.
True
In a mitral valve prolapse, a portion of the bicuspid valve protrudes into the left atrium.
True
Purkinje fibers transmit the action potential from the apex of the heart to the ventricles.
True
Regular exercise increases cardiac output, decreases blood pressure, aids in weight control and increases fibrinolytic activity.
True
The pericardium consists of a fibrous and serous layer. The visceral layer of the serous pericardium may be referred to as the epicardium.
True
The relationship between preload and end diastolic volume is referred to as the Frank-Starling law.
True
The right atrium receives blood from the coronary sinus. True False
True
The right atrium receives blood from the superior and inferior vena cava and the coronary sinus while the left atrium receives blood from the 4 pulmonary veins.
True
The sympathetic impulses increase heart rate and contraction force while parasympathetic impulses decrease heart rate.
True
What activity does the P wave represent atrial depolarization diastole ventricular systole atrial systole
atrial depolarization
Which of the following occurs during that portion of the EKG designated as the P wave? high pressure in the ventricles opens the A-V valves high pressure in the aorta and pulmonary trunk open the A-V valves atrial myocardium depolarizes ventricular myocardium repolarizes
atrial myocardium depolarizes
Tension in the chordae tendineae and papillary muscles during ventricular systole prevent contraction of the atria blood flow into the aorta and pulmonary trunk backflow of blood into the atria closing of the AV valves
backflow of blood into the atria
The first heart sound is associated with
both atrioventricular valves closing during ventricular systole
Which of the following is not a function of A, B and C? confine the heart to its position in the mediastinum prevent overstretching of the heart contract the heart reduce friction as the heart moves
contract the heart
Veins in the myocardium drain into the posterior ventricular artery coronary sinus marginal artery anterior interventricular artery
coronary sinus
Which of the following is a benefit of regular aerobic training?
increased maximal cardiac output during strenuous exercise
Nerve impulses that reach the heart by means of the vagus nerve are
parasympathetic and cause decreased heart rate
Which of the following represents the correct pathway of blood moving from the superior vena cava to the lungs? pulmonary semilunar valve, right atrium, tricuspid valve, right ventricle right atrium, pulmonary semilunar valve, right ventricle, tricuspid valve right atrium, tricuspid valve, right ventricle, pulmonary semilunar valve occurs only on myelinated fibers
right atrium, tricuspid valve, right ventricle, pulmonary semilunar valve
he right atrium receives blood directly from 3 vessels. They are the superior vena cava, inferior vena cava, and left internal jugular vein superior vena cava, coronary sinus, and left internal jugular vein superior vena cava, inferior vena cava, and coronary sinus inferior vena cava, right internal jugular vein and left internal jugular vein
superior vena cava, inferior vena cava, and coronary sinus
The plateau phase of depolarization of muscle fibers in the ventricles of the heart extends from
the QRS to the T wave of the ECG
