The wall of the left ventricle is thicker than the right because
both the left ventricle does more work than the right ventricle and the left ventricle produces a higher pressure than the right.
Blood returning to the heart from the pulmonary circuit first enters the
Compared to the right ventricle, the left ventricle has all the following characteristics, except that it
pumps a greater volume
Tetanic muscle contractions don't occur in a normal cardiac muscle because
the refractory period lasts until the muscle relaxes.
What effect would compressing the inferior vena cava just below the diaphragm have on cardiac function?
Sympathetic stimulation of the heart would increase.
Artery is to ________ as vein is to ________.
Intercalated discs serve to transfer ________ from cell to cell.
the force of contraction ionic currents action potentials
The foramen ovale in the fetal heart is located in the
Blood is supplied to the myocardium by
the coronary arteries.
Contractions of the papillary muscles
prevent the atrioventricular valves from reversing into the atria.
The inferior point of the heart is called the ________.
The pulmonary semilunar valve prevents backward flow into the
When the left ventricle contracts, the diameter of the ventricular chamber
Blood flowing into the heart from the venae cavae flows next through the ________ valve.
The circumflex branch and the anterior interventricular artery are branches of the
left coronary artery
The atrioventricular valves permit blood flow
in one direction only
In the middle of the thoracic cavity is a region occupied by the heart, great vessels, thymus, esophagus, and trachea called the
The right ventricle pumps blood to the
right and left lungs
The ________ valve prevents backward flow into the left atrium.
The left ventricle pumps blood to the
As blood leaves the right ventricle it passes through the ________ and then into the pulmonary trunk.
The pulmonary veins carry blood to the
The first blood vessels to branch from the aorta are the ________ arteries.
When the semilunar valves close, the AV valves then
The cusps (leaflets) of atrioventricular valves attach directly to
Most of the middle layer in the heart wall is composed of
The bicuspid or mitral valve is located
between the left atrium and left ventricle.
The following is a list of vessels and structures that are associated with the heart.
1. right atrium 2. left atrium 3. right ventricle 4. left ventricle 5. venae cavae 6. aorta 7. pulmonary trunk 8. pulmonary veins
5, 1, 3, 7, 8, 2, 4, 6
The heart pumps approximately ________ liters of blood each day.
Blood returning to the heart from the systemic circuit first enters the
The right atrium receives blood from the
coronary sinus, superior vena cava, and inferior vena cava.
The earlike extension of the atrium is the
The structure that permits blood flow from the right atrium to the left atrium in the fetal circulation is the
The coronary sulcus is a groove that
marks the border between the atria and ventricles.
When the left ventricle contracts, the distance from the apex to the base
The ________ deliver(s) blood to the myocardium.
both right coronary artery and left coronary artery
Coronary veins empty into the
The function of the atrium is to
both collect blood and pump blood to the ventricle.
Blood leaves the right ventricle by passing through the
The visceral pericardium is the same as the
The pulmonary arteries carry blood to the
The interventricular sulci and coronary sulcus contain
ateries, fat, veins
The heart is roughly the size of
a man's clenched fist
Which of the following descriptions matches the term near the left fifth intercostal space?
There are ________ pulmonary veins.
The marginal branch and posterior interventricular branch are branches of the
right coronary artery
The great and middle cardiac veins drain blood into the
The term used to describe fluid collecting in the pericardial cavity that restricts the movement of the heart is known as
The connective tissue fibers of the myocardium
help distribute the forces of contraction. add strength and prevent overexpansion of the heart. provide elasticity to help return the heart to its normal size. provide physical support for cardiac muscle.
Blood is supplied to the left atrium by the
left coronary artery
Excess fluid in the ________ causes cardiac tamponade.
In order to perform a CABG, a cardiac surgeon must
both open the pericardial sac and visualize the visceral pericardium.
The heart lies within the ________.
The superior portion of the heart where major blood vessels enter and exit is the ________.
An equivalent term for epicardium is ________.
The wall of the ________ rests on the diaphragm.
The space between the pleural cavities is called the ________.
The ________ is shared by the two ventricles.
Muscular ridges on the inner surface of the ventricles are called ________.
The ________ circuit carries blood to and from the lungs.
The ________ circuit carries blood from the aorta to the right ventricle.
________ carry blood away from the heart.
________ carry blood toward the heart.
The ________ covers the outer surface of the heart.
The muscle layer of the heart is the ________.
The ________ lines the chambers of the heart, covers the heart valves, and is continuous with the endothelium.
Oxygen is added to blood as it flows through the ________ circuit.
In a procedure known as balloon ________, an inflatable balloon at the end of a catheter is used to press plaque back against the vessel wall.
A procedure in which a length of the patient's vein or artery is used to create a detour around an obstruction in a coronary artery is called ________.
A fine tubular wire mesh called a ________ may be inserted into a coronary vessel, holding it open.
As the left ventricle contracts, it bulges into the ________.
right ventricular cavity
The ________ is a remnant of an important fetal blood vessel that once linked the pulmonary and systemic circuits.
The heart has four chambers, two small thin-walled ________ and two large muscular ________.
The long-term success rate of angioplasty greatly increases with the use of stents.
A slower-than-normal heart rate is called ________.
In cardiac muscle
at least half of the calcium ion required for contraction comes from outside the cell.
A faster-than-normal heart rate is called ________.
At a heart rate of 60 beats/minute, a cardiac cycle lasts
Which of these comparisons between skeletal and heart muscle is false?
both rely entirely on oxidative metabolism for energy.
Which of the following is greater during left ventricular systole?
the peak pressure in the ventricle
If there is a complete block between the SA node and the AV node, how would the ECG be affected?
The rate of P waves will be faster than the rate of QRS complexes.
If the connection between the SA node and AV node becomes blocked,
the ventricles will beat more slowly
The long plateau phase of the cardiac muscle action potential is due to
calcium channels remaining open
An increase in the rate of action potentials from baroreceptors will reflexly lead to
both decrease in heart rate and decrease in blood pressure.
During the T wave of the electrocardiogram, the ventricles are
both repolarizing and relaxing.
Depolarization of the atria corresponds to the EKG's
As a result of the long refractory period in the cardiac action potential, cardiac muscle cannot exhibit
The following are structural components of the conducting system of the heart.
1. Purkinje fibers 2. AV bundle 3. AV node 4. SA node 5. bundle branches
The sequence in which excitation would move through this system is
4, 3, 2, 5, 1
The normal pacemaker of the heart is located in the
The P wave of the electrocardiogram is a signal from
depolarization of the atria
The T wave on an ECG tracing represents
Depolarization of the ventricles is represented on an electrocardiogram by the
Cardiac cells damaged by infarction will show which of the following?
release of troponin T and I into the circulation. switch to anaerobic metabolism. release of enzymes into the circulation. release of MB-CK into the circulation.
Which part of the conduction system initiates the depolarizing impulse, which spreads throughout the heart?
What does the ECG wave tracing represent?
electrical activity in the heart
What does the QRS complex represent in the ECG wave tracing?
Contraction of the atria results from which wave of depolarization on the ECG tracing?
Which part of the intrinsic conduction system delays the impulse briefly before it moves on to the ventricles?
A heartbeat lasts
If the pacemaker cells in the SA node become more permeable to potassium ions, the
both heart rate will decrease and membrane will hyperpolarize
Analysis of the electrocardiogram can reveal all of the following, except the
When a blood clot forms on a ruptured plaque in a coronary artery, the condition is referred to as a(n)
AV nodal cells are poorly interconnected compared to contractile cells but they have bigger diameters.
The first part of the statement is true but the second part is false.
Abnormally slow depolarization of the ventricles would most change the shape of the ________ in an ECG tracing.
The property of heart muscle to contract in the absence of neural or hormonal stimulation is called ________.
Cells that spontaneously make action potentials make up ________ tissue.
The structures responsible for distributing excitation to the contractile cells are ________.
The two types of cardiac muscle cells involved in a normal heartbeat include specialized cells of the ________ system and ________ cells.
A heart murmur might be caused by
aortic valve stenosis or mitral valve insufficiency or pulmonic valve insufficiency.
The relaxation phase of the cardiac cycle is called ________.
________ is when the heart can't maintain adequate cardiac output.
As the heart rate slows, ________ gets longer.
If the connection between the vagus nerve and the heart is cut, which of these changes will occur?
NONE OF THE ABOVE NOT: (stroke volume will decrease, heart will beat slower, cardiac output will decrease, nodal fibers will depolarize more slowly )
During the isovolumetric phase of ventricular systole, the
atrioventricular valves and semilunar valves are closed.
The one-way nature of the left AV valve prevents blood flow from _________.
the left ventricle to the left atrium
The closing of the left AV valve occurs near the beginning of __________.
The majority of ventricular filling occurs while the ventricles and atria are in what state(s)?
ventricular and atrial diastole
Which of the following most correctly describes end-diastolic volume?
the volume of the ventricle when it is most full
Left ventricular filling occurs __________.
while the AV valve is open
Heart valves are in what state during isovolumetric contraction?
The AV valves and semilunar valves are closed.
The decrease in left ventricular pressure at the end of ventricular systole causes __________.
the semilunar valve to close
Ventricular diastole begins with the closing of the semilunar valves. What phase of the cardiac cycle happens between this event and the later opening of the AV valves?
The contraction phase of the cardiac cycle is called ________.
Compared to the right ventricle, which of these statements about the left ventricle is false?
it ejects more blood
The first heart sound is heard when the
AV valves close.
During the cardiac cycle, the
both QRS complex of the ECG precedes the increase in ventricular pressure and first heart sound coincides with the QRS complex of the ECG.
Isovolumetric relaxation and ventricular filling (two phases of the cardiac cycle) take place during __________.
Which of the following is correct about the filling of the ventricles?
Most blood flows passively into the ventricles through open AV valves.
Describe the pressures in the atria and ventricles that would cause the opening of the AV valves.
Pressure in the atria would be greater than the pressure in the ventricles.
What causes the aortic semilunar valve to close?
greater pressure in the aorta than in the left ventricle
Put the phases of the cardiac cycle in the correct order, starting after ventricular filling.