Ch. 18 The Heart Flashcards
Which structure forms the most superficial covering of the heart?
Fibrous pericardium is the outermost layer of the pericardium
Which blood vessel returns blood to the heart from areas below the diaphragm?
Inferior vena cava
Which heart valve prevents backflow into the atrium?
Tricuspid valve
Which of the following statements is true?
A) The left ventricular cavity is flattened into a crescent shape
B) The right ventricular cavity is nearly circular
C) The right ventricle pumps blood at a higher pressure than the left ventricle
D) The left ventricle wall is thicker than the right
D) The left ventricle wall is thicker than the right
The right ventricle pumps blood into what structure?
Pulmonary trunk
Select the coronary vessel that supplies oxygen-rich blood to the left atrium and the posterior walls of the left ventricle
A) Anterior interventricular artery
B) Circumflex artery
C) Great cardiac vein
D) Coronary sinus
B) Circumflex artery
Which side of the heart pumps first?
Both sides of the heart pump at the same time
Which anatomical or physiological feature correctly describes cardiac muscle and not skeletal muscle?
A) Striations appear as alternating light and dark bands
B) Sarcoplasmic reticulum stores and releases calcium ions
C) Intercalated discs connect adjacent muscle cells
D) Calcium ions bind troponin to signal contraction
C) Intercalated discs connect adjacent muscle cells
Which component of the conduction system sets the pace for the heart as a whole?
Sinoatrial (SA) node
Identify the component of the EKG that corresponds to the depolarization of the ventricles.
QRS complex
What happens when the ventricular pressure exceeds aortic pressure?
The semilunar valves open
What cardiac term refers to the volume of blood remaining in a ventricle after contraction?
End Systolic Volume (ESV)
Select the factor that increases cardiac output:
A) Increased preload
B) Increased parasympathetic activity
C) Decreased venous return
D) Decreased stroke volume
A) Increased preload
Situation in which a relatively mild blow to the chest causes heart failure and sudden death because it occurs during a vulnerable interval
Commotio cordis
A condition of right-sided heart failure resulting from elevated blood pressure in the pulmonary circuit
Cor pulmonale
The leading cause of death in young athletes, usually inherited, causes the cardiac muscle cells to enlarge; the heart pumps strongly, but doesn’t relax well during diastole
Hypertrophic cardiomyopothy
When the semi-lunar valves are open, which of the following is happening?
A) Coronary arteries fill B) AV valves are closed C) Ventricles are in systole D) Ventricles are in diastole E) Blood enters the aorta F) Blood enters the pulmonary arteries G) Atria contract
A) Coronary arteries fill
Cardiac output is ?
the amount of blood pumped out of each ventricle in one minute
What is the correct sequence of electrical current flow through the heart wall?
SA node, AV node, AV bundle, right and left bundle branches, subendocardial conducting network
During pulmonary circulation, blood leaves the ?
right ventricle and flows directly to the lungs
During systemic circulation, blood leaves the ?
left ventricle and flows directly to the aorta
The absolute refractory period refers to the time during which ?
the muscle cell will not respond to a stimulus of any strength
The cardiac cycle includes all of the following events EXCEPT ?
A) the changes in pressure gradients in all chambers of the heart
B) the movement of impulse from the SA node to all regions of the heart wall
C) the number of times the heart beats in one minute
D) the changes in blood volume in all chambers of the heart
E) the closing and opening of the heart valves during each heartbeat
the number of times the heart beats in one minute
The coronary arteries arise from the ?
aorta
The endocardium is composed of ?
squamous epithelium
The structure just deep to the fibrous pericardium is the ?
parietal layer of the serous pericardium
When the mitral valve closes, it prevents the backflow of blood from the ?
left ventricle into the left atrium
Which is the correct sequence of layers in the heart wall, starting with the outer layer?
epicardium, myocardium, endocardium
The contractile cardiac muscle fibers of the myocardium behave as a single, coordinated unit called a ?
functional syncytium
The noncontractile cardiac muscle cells that initiate their own depolarization and cause depolarization of the rest of the heart are called ?
pacemaker cells
Guided by powerful signaling molecules, the human heart develops from ?
mesoderm
The trabeculae carneae are located in the ?
ventricles
The ____ are attached to the AV valve flaps.
chordae tendineae
Which valve is most often faulty in the heart?
the mitral, or bicuspid, valve
What factor gives the myocardium its high resistance to fatigue?
a very large number of mitochondria in the cytoplasm
The ______ nerve carries parasympathetic fibers to the sinoatrial (SA) node.
vagus
An enlarged R wave on an ECG would indicate ?
an enlarged ventricle
The fibrous pericardium is the superficial part of the pericardium that encloses the heart. It ____ the heart, prevents the heart from ____ with blood, and ____ the heart to surrounding structures.
protects; overfilling; anchors
supplies blood to the lateral right side of the myocardium
right marginal artery
blood vessel that runs to the apex of the heart
posterior interventricular artery
supplies blood to the interventricular septum and anterior walls of both ventricles
anterior interventricular artery
supplies blood to the left atrium and posterior walls of the left ventricle
circumflex artery
The role of the atrioventricular node (AV node) is to ?
slow down impulses so that the atria can contract to fill the adjacent ventricles with blood
The second heart sound (the “dup” of “lub-dup”) is caused by the ?
closure of the semilunar valves
T/F
In the fetus, blood from the left and right sides of the heart normally mix.
True
