Chapter 20: The Heart
The heart beats approximately_________ times each day.
100,000
Blood returning to the heart from the pulmonary circuit first enters the?
left atrium
Blood is supplied to the muscular wall of the left atrium by the?
left coronary artery
The circumflex branch and the anterior inter ventricular artery are branches of the?
left coronary artery
Rupture of the papillary muscles in the left ventricles may result in?
mitral valve prolapse
Oxygen is added to blood as it flows through the__________ circuit.
pulmonary circuit
Coronary veins empty into the?
right atrium
As a result of the long refractory period in the cardiac action potential, cardiac muscle cannot exhibit
tetany
There are______ pulmonary veins.
4
The earlobe extension of the atrium is the?
auricle
The first blood vessels to branch from the aorta are the ______________ arteries?
coronary
Which statement correctly describes the term left atrioventricular valve? a) Its cusps open into the left atrium b) Its cusps open into the superior vena cava c) Its cusps open into the aorta d) Its cusps open into the left ventricle e) Its cusps open into the pulmonary trunk
d) Its cusps open into the left ventricle
Which of the following is not true regarding the right atrioventricular valve? a) It has 3 cusps b) It is also called the tricuspid valve c) It prevents backflow from the right ventricle into the right atrium d) the valve closes when the right atrium contracts e) The cusps provide one-way flow of blood
d) The valve closes when the right atrium contacts
The visceral pericardium is the same as the?
epicardium
The_______ is shared by the two ventricles.
interventricular septum
Which chamber has the thickest wall?
left ventricle
In the middle of the thoracic cavity is a region occupied by the heart, great vessels, thymus, esophagus, and trachea called the?
mediastinum
The pulmonary veins carry blood to the?
heart
If the pacemaker cells in the SA node becomes more permeable to potassium ions, the
heart rate will decrease and cells will hyperpolarize
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
These structures keep the aortic valve cusps from sticking to the wall if the aorta.
aortic sinuses
The inferior point of the heart is called the?
apex
The_________ carry blood away from the heart.
arteries
The __________ valve prevents backwards flow into he left atrium?
bicuspid
________ is to slow heart rate as ______ is to fast heart rate.
bradycardia; tachycardia
In cardiac muscle, the fast depolarization phase of the action potential is the result of
increased membrane permeability to sodium ions
The atrioventricular valves permit blood flow in?
one direction only
The right pulmonary veins carry___________blood to the _______________.
oxygenated; left atrium
Prominent muscular ridges in the anterior atrial wall and auricle are called?
pectinate muscles
Contractions of the papillary muscles do what?
prevent the atrioventricular valves from reversing into the atria
One possible consequence of untreated strep throat id a disease causing inflammation of heart called?
rheumatic fever
The right ventricle pumps blood to the?
right and left lungs
The marginal branch and posterior inter ventricular branch are branches of the?
right coronary artery
The pulmonary valve prevents backward flow into the?
right ventricle
Blood is supplied to the myocardium by?
the coronary arteries
Tetanic muscle contractions don't occur in a normal cardiac muscle because
the refractory period last until the muscle relaxes
If the connection between the SA node and AV node becomes blocked,
the ventricles will beat more slowly
The heart pumps approximately_________ liters of blood each day.
8,000
Pacemaker cells isolated from the SA node generate action potentials at_________ beats per minutes.
80-100
The function of an atrium is to?
collect blood then pump it into the ventricle
As blood laves the right ventricle, it passes through__________ and then into the pulmonary trunk.
conus arteriosus
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?
coronary artery bypass graft
The term __________ refers to blockage in the coronary circulation.
coronary artery disease
The great and middle cardiac veins drain blood into the?
coronary sinus
When a blood clot forms on the ruptured plaque in a coronary artery, the condition is referred to as a(n)?
coronary thrombosis
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
Cardiac muscle layers form this distinct pattern.
figure eight
Thick projections of muscle in the ventricles that anchor chord tenineae are called?
papillary muscles
Blood leaves the right ventricle by passing through the?
pulmonary valve
The________ carry blood toward the heart.
veins
The T wave on the ECG tracing represents
ventricular repolarization
The following is a list of vessels and structures that are associated with 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. venae cavae 1. right atrium 3. right ventricle 7. pulmonary trunk 8. pulmonary veins 2. left atrium 4. left ventricle 6. aorta
The adult heart is roughly the size of?
A man's clenched fist
Analysis of the electrocardiogram can reveal all of the following except a) heart rate b) stroke volume c) the condition of the conducting system d) the effects of drugs and poisons e) the duration of the ventricular potential
b) stroke volume
In a procedure known as____________, an inflatable ballon at the end of a catheter is used to press plaque back against the vessel wall.
balloon angioplasty
The superior portion of the heart where major blood vessels enter and exist is the?
base
The bicuspid or mitral valve is located?
between the left atrium and left ventricle
Compared to the right ventricle, the left ventricle has all the following characteristics except? a) has a thicker wall b is round in cross section c) pumps a greater volume d) works harder e) produces about four to six times more pressure when it contracts
c) pumps a greater volume
The long plateau phase of the cardiac muscle action potential is due to
calcium channels remaining open
Most of the middle layer of the heart wall is composed of?
cardiac muscle cells
The coronary sinus drains the ________ into the___________.
cardiac veins; right atrium
Rheumatic fever causes generalized inflammation of the heart called?
carditis
The cusps (leaflets) of atrioventricular valves attach directly to?
chordae tendineae
Which of the following statement is true regarding cardiac muscle? a) Its main source of ATP production is glycogen b) The actin and myosin myofilaments are to arranged in sarcomeres c) Cardiac muscle preferentially metabolizes anaerobically d) There are specialized gap junctions in cardiac muscles not found in skeletal or smooth muscles e) Cardiac muscle goes into sustained contractions faster than skeletal muscle
d) There are specialized gap junctions in cardiac muscle not found in skeletal or smooth muscles
The connective tissue of the heart are important for all of the following reasons except? a) they help distribute the forces of contraction b) they prevent overexpansion of the heart c) they provide support for blood vessels and nerves d) they produce the pericardial fluid
d) they produce the pericardial fluid
Cardiac muscle cells and skeletal muscle cells differ in a few ways. Which of the following is not one of them? a) Cardiac muscle cells are smaller in size b) Cardiac muscle cells have a single, centered nucleus c) Cardiac muscle cells branch d) Skeletal muscle cells lack intercalated discs e) Cardiac muscle cells lack transverse tubules
e) Cardiac muscle cells lack transverse tubules
Which of the following statements is true concerning differences between the right and the left ventricles? a) The right ventricle pumps with more force compared to the left b) The left ventricle pumps twice as much blood as the right ventricle c) The right ventricle pumps blood to the body, whereas the left ventricle pumps blood to the lungs d) The right ventricle is conical-shaped while the left ventricle is half-moon shaped e) The efficiency of the right ventricle is increased by the left because the wall of the left ventricle pushes into the right ventricle
e) The efficiency of the right ventricle is increased by the left because the wall of the left ventricle pushed into the right ventricle
Cardiac cells damaged by infarction will show all of the following except? a) a switch to anaerobic metabolism b) release of enzymes into the circulation c) release of troponin T and I into the circulation d) release of CK-MB into the circulation e) an increase in metabolic activity
e) an increase in metabolic activity
A hole in the interventricular septum in an infant may cause all of the following symptoms except a) mixing of oxygen-rich and oxygen-poor blood b) a murmur to be heard c) the heart work harder d) the individual to have a low peripheral oxygen saturation e) build-up of atherosclerotic plaque
e) build-up of atherosclerotic plaque
The structure that permits blood flow from the right atrium to the left atrium in the fetal circulation is the what?
foramen ovale
An MI that affects the________ side of the heart is more severe because it has to pump blood with _______ force.
left; more
The____________ is a remnant of an important fetal blood vessel that once linked the pulmonary and systemic circuits.
ligamentum arteriosum
The___________ is an important ridge of muscle extending horizontally around the right ventricle from the interventricular septum to the base of the anterior papillary muscle containing part of the conducting system.
moderator band
The muscular layer of the heart is the?
myocardium
The heart lies within the __________ cavity.
pericardial
The_______ circuit carries blood to and form the lungs.
pulmonary
The right atrium receives blood from all of the following structures except? a) coronary arteries b) superior vena cava c) inferior vena cava d) systemic circuit e) pulmonary veins
pulmonary veins
Which of the following are involved in the pulmonary circuit? -superior vena cava, right atrium, left ventricle -right ventricle, pulmonary veins, aorta -right ventricle, pulmonary trunk, left atrium -inferior vena cava, right atrium, aorta -left ventricle, pulmonary veins, right atrium
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 the?
sinoatrial node
A fine tubular wire called a __________ may be inserted into a coronary vessel, holding it open.
stent
The_________ circuit carries blood from the aorta to the right ventricle.
systemic
Muscular ridges on the inner surface of the ventricles are called?
trabeculae carneae
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. SA node 3. AV node 2. AV bundle 5. bundle branches 1. Purkinje fibers
__________ is the symptom generally brought on by coronary ischemia.
Angina pectoris
The term used to describe fluid collecting in the pericardial cavity that restricts the movement of the heart is know as the?
Cardiac tamponade
The P wave of the electrocardiogram is a signal from
depolarization of the atria
Blood returning to the heart from the systemic circuit first enters the?
Right atrium
The left ventricle pumps blood to the?
aorta
The foramen ovale in the fetal heart is located in the?
interatrial septum
Pericardial fluid
is a lubricant between the heart and the pericardial sac
Which valve(s) contain 2 cusps?
left AV valve
The pulmonary arteries carry blood to the?
lungs
The coronary sulcus is a grove that?
marks the border between the atria and ventricles
Which valve(s) cusps open up toward the base of the heart?
aortic and pulmonary valves
Depolarization of the atria corresponds to the EKG's
P wave
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 the QRS complexes
In cardiac muscle,
about 20% of the calcium ions required for concentration comes from outside the cell
