Ch.20
During the isovolumetric contraction period of the cardiac cycle, AV and semilunar valves are closed. the atria are contracted. ventricular volume increases. blood is pumped into the large arteries. pressure in the ventricles decreases.
AV and semilunar valves are closed.
When ventricular pressure exceeds atrial pressure, the ejection occurs. atria pump blood into the ventricles. ventricle is in diastole. blood is pumped into the atrium. AV valves close.
AV valves close.
Knowing the location of the heart is important for -positioning a stethoscope to hear heart sounds. -placing electrodes to record an electrocardiogram. -effective cardiopulmonary resuscitation. -All of these choices are correct
All of these choices are correct
Covers surfaces of the heart valves:
Endocardium
The inner surface of the heart:
Endocardium
Also known as the visceral pericardium:
Epicardium
Thin serous membrane of the outer surface of the heart:
Epicardium
T or F: Cardiac muscle has refractory periods, during the relative refractory period, the cell is completely insensitive to further stimulation. The plateau phase of the action potential in cardiac muscle delays repolarization to the resting membrane potential therefore the refractory period is prolonged.
False True
The pericardium consists of a tough, fibrous connective tissue outer layer called the __________ pericardium.
Fibrous
What is the importance of the delay in the action potential in the AV node? It allows the action potential to reach both ventricles at the same time. It allows an action potential to reach the left atrium so both atria contract together. It slows the rate of contraction of the ventricles. It allows time for the atria to be filled with blood.
It allows an action potential to reach the left atrium so both atria contract together.
Pulmonary veins:
Left atrium
The __________ has four relatively uniform openings that receive blood from the four pulmonary veins from the lungs. right atrium left atrium right ventricle left ventricle
Left atrium
Aorta:
Left ventricle
The wall of the __________ is much thicker than any other chamber in the heart which allows for stronger contractions to pump blood through the systemic circulation. right atrium left atrium right ventricle left ventricle
Left ventricle
Mean arterial pressure = CO X PR Cardiac output = HR X SV Total force against which the blood must be pumped = Peripheral resistance Heart rate = Heart beats/Minute Stroke volume = EDV-ESV
Match terms with definitions
Composed of cardiac muscle cells:
Myocardium
Thick middle layer of the heart:
Myocardium
The __________ sac is a double layered, closed sac that surrounds the heart.
Pericardial
In a normal electrocardiogram, the
QRS complex results from ventricular depolarization.
Inferior and superior vena cava:
Right atrium
Pulmonary trunk:
Right ventricle
Place the components of the electrical conducting system in order from the initiation of an action potential to the end: Right and left bundle branches Atrial myocardium AV node SA node Purkinje fibers AV bundle
SA node Atrial myocardium AV node AV bundle Right and left bundle branches Purkinje fibers
The "pacemaker" of the heart is the right bundle branch. left bundle branch. AV node. SA node. PM node.
SA node.
The inner layer of the pericardium is a thin, transparent layer of simple squamous epithelium called the __________ pericardium.
Serous
Concerning heart sounds, which of the following is correct? The first heart sound occurs at the beginning of ventricular systole. The second heart sound is heard when the AV valves are closing. The first heart sound is the sound of the semilunar valves closing. The second heart sound occurs when blood flows into the superior vena cava. The first heart sound occurs at the beginning of ventricular diastole.
The first heart sound occurs at the beginning of ventricular systole.
The epicardium is also known as the __________ pericardium.
Visceral
The period of time in which the myocardium is insensitive to further stimulation is called the absolute refractory period. hyperpolarization period. AV period. SA period. ectopic focus.
absolute refractory period.
When comparing cardiac muscle cells and skeletal muscle cells, the rate of action potential propagation is faster in cardiac muscle. both possess intercalated discs. only skeletal muscle has a plateau phase in its contraction cycle. action potentials are conducted from cell to cell only in cardiac muscle. both are voluntary.
action potentials are conducted from cell to cell only in cardiac muscle.
In the cardiac cycle, the right atrium and the right ventricle contract simultaneously. the left atrium contracts before the right atrium. all four chambers of the heart contract at the same time. all four chambers of the heart are in diastole at the same time.
all four chambers of the heart are in diastole at the same time.
Within normal limits, an increase in preload leads to an increase in cardiac output and force of left ventricular contraction. a decrease in cardiac output and force of left ventricular contraction. an increase in cardiac output and a decrease in force of left ventricular contraction. a decrease in cardiac output and an increase in the force of left ventricular contraction. a decrease in stroke volume and heart rate.
an increase in cardiac output and force of left ventricular contraction.
The _______ carries blood from the left ventricle to the body.
aorta
What vessel exits the left ventricle? pulmonary trunk pulmonary vein aorta pulmonary artery
aorta
Which blood vessel carries blood from the left ventricle? aorta right atrium pulmonary trunk pulmonary arteries pulmonary veins
aorta
The __________ valve consists of three pocketlike cusps and is found in the base of the vessels that leaves the left ventricle. tricuspid valve bicuspid valve pulmonary semilunar aortic semilunar
aortic semilunar
As soon as left ventricular pressure exceeds the pressure in the aorta, the AV valves open. aortic semilunar valve opens. atria pump blood into the ventricles. ventricles pump blood into the atria. pulmonary semilunar valve closes.
aortic semilunar valve opens.
Ventricular contraction begins at the AV bundle. apex of the heart. base of the heart. superior portion of the interventricular septum. top of the ventricles.
apex of the heart.
Cardiac muscle cells have smooth ER but no T tubules. form the heart valves. are maintained by an extensive capillary network. develop a significant oxygen debt during systole. do not contain actin and myosin like skeletal muscle cells.
are maintained by an extensive capillary network.
The P wave of an ECG indicates atrial depolarization. atrial repolarization. ventricular depolarization. ventricular repolarization. threshold.
atrial depolarization.
The heart is said to be __________ because it stimulates itself to contract at regular intervals.
autorhythmic
When blood pressure increases baroreceptors detect the change in the carotid arteries. the cardioregulatory center decreases parasympathetic stimulation of the heart. heart rate and stroke volume increase. norepinephrine secretion increases.
baroreceptors detect the change in the carotid arteries.
Blood vessels enter and exit from the _____ of the heart. apex base auricles trigone inferior aspect
base
The AV valve that is located on the same side of the heart as the origin of the aorta is the bicuspid or mitral valve. tricuspid valve. aortic semilunar valve. pulmonary semilunar valve. coronary sinus valve.
bicuspid or mitral valve.
When blood pH increases: baroreceptors detect the change in the carotid arteries. the cardioregulatory center decreases parasympathetic stimulation of the heart. heart rate and stroke volume increase. blood carbon dioxide levels increase.
blood carbon dioxide levels increase.
Baroreceptor reflexes are triggered by increased blood osmolality. correct changes in blood pH. do not impact the activity of the heart. are of minor importance in humans. can change heart rate.
can change heart rate.
The product of the stroke volume times the heart rate is known as the end-diastolic volume. end-systolic volume. cardiac output. cardiac reserve. venous return.
cardiac output.
Which of the following is mismatched? opening of sodium channels - depolarization closing of calcium channels - plateau phase opening of potassium channels - rapid repolarization closure of sodium channels - early repolarization opening of calcium channels - plateau phase
closing of calcium channels - plateau phase
The chordae tendineae connect the atria to the ventricles. are found in the interventricular septum. are part of the conducting system of the heart. connect the flaps of the AV valves to the papillary muscles. are a part of the myocardium.
connect the flaps of the AV valves to the papillary muscles.
The great cardiac vein and middle cardiac vein empty into a venous cavity called the pulmonary vein. inferior vena cava. superior vena cava. coronary sinus. coronary artery.
coronary sinus
All cardiac veins empty into the _________, which then empties into the _______. coronary sinus; left atrium coronary sinus; right atrium great cardiac vein; right atrium great cardiac vein; superior vena cava inferior vena cava; left atrium
coronary sinus; right atrium
The epicardium covers the surface of the heart. lines the walls of the ventricles. is known as the fibrous pericardium. attaches inferiorly to the diaphragm. is also called endocardium.
covers the surface of the heart.
What event(s) occur during the QRS complex of an ECG? depolarization of the atria repolarization of the ventricles depolarization of the atria and repolarization of the ventricles depolarization of the ventricles and repolarization of the atria
depolarization of the ventricles and repolarization of the atria
The tricuspid valve is closed during active filling of the ventricles. when the mitral valve is open. while the atria are contracting. during ejection. during passive filling of the ventricles.
during ejection.
The smooth inner lining of the heart chambers is the __________.
endocardium
Another name for the visceral pericardium is the endocardium. epicardium. isocardium. myocardium. visocardium.
epicardium
The __________ is a low-pitched sound caused by vibration of the atrioventricular valves and surrounding fluid as the valves close at the beginning of ventricular systole. first heart sound second heart sound third heart sound fourth heart sound
first heart sound
Stimulation of the heart via the sympathetic nerves would decrease heart rate. decrease stroke volume. increase the force of ventricular contraction. increase end-systolic volume. not affect heart rate and force of contraction.
increase the force of ventricular contraction.
The baroreceptor reflex would cause which of the following events to occur if the reflex was caused by an increase in blood pressure? increased parasympathetic stimulation of the heart increased heart rate increased cardiac output increased force of contraction increased sympathetic stimulation of the heart
increased parasympathetic stimulation of the heart
Coronary artery disease can diminish myocardial blood flow resulting in the death of myocardial cells. This condition is known as a myocardial attack. angina. necrosis. cirrhosis. infarction.
infarction
The heart is a four-chambered muscular pump. is posterior to the trachea. is lined with an epithelial layer called epicardium. lies mostly to the right of the midline of the sternum. has a superior apex and an inferior base.
is a four-chambered muscular pump.
Blood does not enter or leave the ventricles during the period called ejection. rapid filling. atrial systole. isovolumetric contraction. active and passive filling.
isovolumetric contraction.
Blood in the pulmonary veins returns to the right atrium. left atrium. right ventricle. left ventricle. coronary sinus.
left atrium
An incompetent mitral valve may cause blood to back up into the aorta. left atrium. left ventricle. coronary circulation. right atrium.
left atrium.
Of the types of damage resulting from a myocardial infarction, which is most likely to cause the greatest increase in the Q-T interval? infarction in the AV node left bundle branch block infarction affecting the SA node tachycardia ectopic focus
left bundle branch block
The chamber of the heart that endures the highest pressure is the right atrium. left atrium. right ventricle. left ventricle. coronary sinus.
left ventricle.
An incompetent pulmonary semilunar valve could result in less blood reaching the lungs. heart muscle. right ventricle. aorta. right atrium.
lungs.
Chemoreceptors sensitive to blood carbon dioxide levels are primarily located in the medulla oblongata. carotid arteries. right atrium. left ventricle. jugular veins.
medulla oblongata.
The cardioregulatory center of the brain is located in the hypothalamus. medulla oblongata. cerebellum. cerebrum. diencephalons.
medulla oblongata.
Which of the following layers forms the bulk of the heart wall? epicardium pericardium endocardium myocardium visceral pericardium
myocardium
The pericardial sac is lined with fibrous pericardium. parietal pericardium. visceral pericardium. myocardium. epicardium.
parietal pericardium
Contraction of the papillary muscles would eject blood from the ventricles. prevent the AV valves from protruding into the atria. close the semilunar valves. cause the atria to eject their contents into the ventricles. open the semilunar valves.
prevent the AV valves from protruding into the atria.
The long refractory period observed in cardiac muscle prolongs depolarization of the cardiac muscle. prevents tetanic contractions of the cardiac muscle. ensures that the heart has adequate time to contract. prevents the heart rate from slowing down. prevents an increase in heart rate.
prevents tetanic contractions of the cardiac muscle.
The right side of the heart receives blood from the body and pumps through _________ circulation to the lungs. hepatic pulmonary peripheral systemic
pulmonary
Which vessels transport blood to the right and left lungs? aorta right atrium pulmonary trunk pulmonary arteries pulmonary veins
pulmonary arteries
The valve located between the right ventricle and the pulmonary trunk is the aortic semilunar valve. pulmonary semilunar valve. tricuspid valve. mitral valve. bicuspid valve.
pulmonary semilunar valve.
From the right ventricle, blood flows directly into the _____. aorta right atrium pulmonary trunk pulmonary arteries pulmonary veins
pulmonary trunk
Pressure in the right ventricle must exceed pressure in the ____ before the right ventricle can eject blood. superior vena cava coronary sinus pulmonary trunk aorta pulmonary veins.
pulmonary trunk
Which of the following is NOT a major opening into the right atrium? pulmonary vein inferior vena cava superior vena cava coronary sinus
pulmonary vein
Blood flows from the lungs to the left atrium via the ________ ________.
pulmonary veins
Which vessels empty blood into the left atrium? aorta right atrium pulmonary trunk pulmonary arteries pulmonary veins
pulmonary veins
The function of the pericardial fluid is to reduce friction between the pericardial membranes. lubricate the heart valves. replace any blood that is lost. provide oxygen and nutrients to the endocardium. stimulate the heart.
reduce friction between the pericardial membranes.
Blood in the superior vena cava will enter the _____. aorta right atrium pulmonary trunk pulmonary arteries pulmonary veins
right atrium
Which of the following heart chambers is correctly associated with the blood vessel that enters or leaves it? right atrium - pulmonary veins left atrium - aorta right ventricle - pulmonary trunk left ventricle - superior vena cava and inferior vena cava right atrium - aorta
right ventricle - pulmonary trunk
The __________ is a higher-pitched sound resulting from closure of the aortic and pulmonary semilunar valves, at the beginning of ventricular diastole. first heart sound second heart sound third heart sound fourth heart sound
second heart sound
Cardiac output is equal to heart rate times ____ _______.
stroke volume
The volume of blood pumped during each cardiac cycle is the stroke volume. cardiac output. cardiac reserve. end-systolic volume. end-diastolic volume.
stroke volume.
The delivery of oxygen and nutrients to the tissues of the body is accomplished through ________ circulation. hepatic pulmonary peripheral systemic
systemic
Contraction of the ventricles is referred to as ventricular systole. diastole. fibrillation. ischemia. depolarization.
systole.
When the heart beats, the right side of the heart contracts before the left side of the heart: false Blood enters the heart from the pulmonary circulation which returns blood from all the tissues of the body: false Contraction of the right ventricle pushes blood against the bicuspid valve, forcing it closed, and against the pulmonary semilunar valve, forcing it open: false Blood flowing through the aorta is taken to all parts of the body except to parts of the lungs supplied by the pulmonary blood vessels: true
t and f
Afterload is the name given to an increase in end-diastolic volume. the arterial pressure that the ventricles must overcome to eject blood. the amount cardiac output must increase during exercise. another name for venous return. the extent to which ventricular walls are stretched.
the arterial pressure that the ventricles must overcome to eject blood.
When left atrial pressure exceeds left ventricular pressure, left ventricular ejection begins. aortic blood pressure begins to rise. the bicuspid (mitral) valve opens. ventricular volume decreases. the tricuspid valve opens.
the bicuspid (mitral) valve opens.
The right atrium receives blood from the lungs and the heart. the heart. the body and the heart. the lungs and the body.
the body and the heart
The period of isovolumetric contraction is immediately followed by the period of ejection. AV node depolarization. passive ventricular filling. atrial contraction. isovolumetric relaxation.
the period of ejection.
In the cardiac cycle, the right atrium and the right ventricle contract simultaneously. the two atria relax while the two ventricles contract. the left atrium contracts before the right atrium. all four chambers of the heart contract at the same time. all four chambers of the heart are in systole at the same time.
the two atria relax while the two ventricles contract.
Why is body temperature sometimes reduced during heart surgery? to slow respiration to increase heart rate to decrease heart rate to increase the oxygen content of blood
to decrease heart rate
The __________ valve is between the right atrium and right ventricle. tricuspid valve bicuspid valve pulmonary semilunar aortic semilunar
tricuspid valve
The first and second heart sounds are most directly related to pulse pressure in the aorta. the contraction of the atria. vibrations that occur when the valves close. contraction of the papillary muscles. the flow of the blood.
vibrations that occur when the valves close.
