Chapter 20: Heart
Which of the following statements is true concerning differences between the right and left ventricles?
The efficiency of the right ventricle is increased by the left ventricle because the wall of the left ventricle pushes into the right ventricle
The earlike extension of the atrium is the
auricle
The function of an atrium is to
collect blood then pump it to the ventricle
The structures responsible for distributing excitation to the contractile cells are
conducting cells
As blood leaves the right ventricle, it passes through the ________ and then into the pulmonary trunk.
conus arteriosus
The first blood vessels to branch from the aorta are the ________ arteries.
coronary
Blood is supplied to the myocardium by
coronary arteries
The structure that permits blood flow from the right atrium to the left atrium in the fetal circulation is the
foramen ovale
The pulmonary veins carry blood to the
heart
The atrioventricular valves permit blood flow
in one direction only
The pulmonary arteries carry blood to the
lungs
The coronary sulcus is a groove that
marks the border between the atria and ventricles
Each of the following factors will increase cardiac output except increased
parasympathetic stimulation
prominent muscular ridges located in the anterior right atrial wall and auricles is called
pectinate muscles
The heart lies within the ________ cavity.
pericardial
Contractions of the papillary muscles
prevent the atrioventricular valves from reversing into the atria.
Which division of the autonomic nervous system would increase heart rate?
sympathetic nervous system
The ________ circuit carries blood from the aorta to the right atrium.
systemic
There are ________ pulmonary veins.
4
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
During ventricular systole, the
AV valves are closed
Abnormally slow depolarization of the ventricles would most change the shape of the ________ in an ECG tracing.
QRS complex
Depolarization of the ventricles is represented on an electrocardiogram by the
QRS complex
Which of the following is not true regarding the right atrioventricular valve?
The valve closes when the right atrium contracts
Which of the following is occurring during ventricular diastole?
The ventricles are passively filling and atria are contracting
The left ventricle pumps blood to the
aorta
The inferior point of the heart is called the
apex
The ________ carry blood away from the heart.
arteries
The superior portion of the heart where major blood vessels enter and exit is the
base
Which of the following would not increase heart rate?
beta blocking drugs
The bicuspid or mitral valve is located
between left atrium and left ventricle
The ________ valve prevents backward flow into the left atrium.
bicuspid
With each ventricular systole,
blood pressure increases
An increase in the rate of action potentials from baroreceptors will trigger a reflex to
both decrease heart rate and decrease pressure
Most of the middle layer in the heart wall is composed of
cardiac muscle cells
The coronary sinus drains the ________ into the ________.
cardiac veins, right atrium
The cusps (leaflets) of atrioventricular valves attach directly to
chordae tendineae
The first heart sound ("lubb") is associated with
closing of the atrioventricular valves (AV valves)
The great and middle cardiac veins drain blood into the
coronary sinus
The P wave of the electrocardiogram is a signal from
depolarization of the atria
The relaxation phase of the cardiac cycle is called
diastole
The ________ lines the chambers of the heart, covers the heart valves, and is continuous with the endothelium.
endocardium
The ________ covers the outer surface of the heart.
epicardium
The visceral pericardium is the same as the
epicardium
Cardiac muscle layers form this distinct pattern.
figure eight
The foramen ovale in the fetal heart is located in the
interartrial septum
Collectively, the conducting cells that carry the impulse from the SA node to the AV node is known as the
internodal pathway
The ________ is shared by the two ventricles.
interventricular septum
Pericardial fluid
is a lubricant between the heart and the pericardial sac
The AV node delay is beneficial because
it allows time for the atria to contract
Blood is supplied to the muscular wall of the left atrium by the
left coronary artery
The circumflex branch and the anterior interventricular artery are branches of the
left coronary artery
Which chamber has the thickest wall?
left ventricle
The ________ side of the heart supplies blood to the systemic circuit, while the ________ side of the heart supplies blood to the pulmonary circuit.
left, right
In the middle of the thoracic cavity is a region occupied by the heart, great vessels, thymus, esophagus, and trachea called the
mediastinum
Heart rate is controlled by neurons of the cardiovascular center located in the
medulla oblongata
Rupture of the papillary muscles in the left ventricle may result in
mitral valve prolapse
The muscle layer of the heart is the
myocardium
The right pulmonary veins carry_________blood to the_________
oxygenated, left atrium
Gradual drifting of membrane potential toward threshold in autorhythmic cells is termed a
pacemaker potential
thick projections of muscle in the ventricles that anchor chordae tendineae are called
papillary muscles
Oxygen is added to blood as it flows through the ________ circuit.
pulmonary
The ________ circuit carries blood to and from the lungs.
pulmonary
Blood leaves the right ventricle by passing through the
pulmonary valve
The right atrium receives blood from all of the following structures except the
pulmonary veins
Compared to the right ventricle, the left ventricle has all the following characteristics, except
pumps a greater volume
The right ventricle pumps blood to the
right and left lungs
Blood returning to the heart from the systemic circuit first enters the
right atrium
Coronary veins empty into the
right atrium
The marginal branch and posterior interventricular branch are branches of the
right coronary artery
The pulmonary valve prevents backward flow into the
right ventricle
Which of the following are involved in the pulmonary circuit?
right ventricle, pulmonary trunk, left atrium
The endocardium consists of this type of tissue.
simple squamous epithelium
The normal pacemaker of the heart is located in
sinoatrial node (SA node)
The volume of blood ejected from each ventricle during contraction is called the
stroke volume
The contraction phase of the cardiac cycle is called
systole
The phase in the cardiac cycle when the mitral valve is closed and the aortic valve is open is the
systolic ejection phase
If the connection between the SA node and AV node becomes blocked,
the ventricles will beat more slowly
The connective tissues of the heart are important for all of the following reasons except
they produce the pericardial fluid
Muscular ridges on the inner surface of the ventricles are called
trabeculae carneae
Beginning with the right atrium, what is the order of the valves through which blood will pass?
tricuspid valve, pulmonary valve, mitral valve, aortic valve
The ________ carry blood toward the heart.
veins
The T wave on an ECG tracing represents
ventricular repolarization
The following is a list of vessels and structures that are associated with the heart. What is the correct order for the flow of blood entering from the systemic circulation? 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
________ is to slow heart rate as ________ is to fast heart rate.
Bradycardia, tachycardia
Which statement correctly describes the term left atrioventricular valve?
Its cusps open into the left ventricle
Depolarization of the atria corresponds to the EKG's
P waves
What happens to the electrical impulse when it reaches the AV node?
it gets delayed
Which valve(s) contains 2 cusps?
left AV valve
Blood returning to the heart from the pulmonary circuit first enters the
left atrium