chapter 17
End-diastolic volume (EDV) for each ventricle at the end of atrial systole is normally about:
120ml
A damaged right bundle branch will prevent the passage of the action potential to the
Purkinje fibers in the right ventricle.
Which wave on the electrocardiogram (ECG) represents ventricular depolarization?
QRS wave
Which of the following can be used to measure heart rate
R-R interval
What best describes the Frank-Starling law?
The Frank-Starling law states that the more the ventricular muscle cells are stretched, the more forcefully they contract.
The long length of the cardiac action potential, at 200-300 msec, allows for
an opportunity for the heart to fill with blood
Where should the left ventricle send blood
aorta
Which vessel supplies the systemic circuit with oxygenated blood
aorta
he right and left coronary arteries receive blood from the
aorta
The P wave on an electrocardiogram (ECG) represents the depolarization of cells in the
atria
Which hormone decreases cardiac output by decreasing blood volume and preload?
atrial natriuretic peptide (ANP)
What is NOT part of the cardiac conduction system
atrioventricular (AV) valve
Which valve is situated between the left atrium and left ventricle
bicuspid (mitral) valve
Which of the following volumes should be the greatest?
cardiac output (CO)
Autorhythmicity in the heart is the responsibility of
cardiac pacemaker cells
Inotropic agents affect
contractility
Generally, coronary veins empty into a vessel known as the
coronary sinus
The right side of the heart receives:
deoxygenated blood from the systemic circuit
The visceral pericardium is the same as the
epicardium
What is the most superficial layer of the pericardial sac
fibrous pericardium
the rapid influx of calcium ions into pacemaker cells creates a positive membrane potential inside the cell and is responsible for the
full depolarization phase
Coronary circulation involves the delivery of oxygenated blood to the
heart
what characteristic differentiates cardiac muscle cells from skeletal muscle cells?
intercalated discs
What surface groove separates the right and left ventricle
interventricular sulcus
he apex of the heart is situated toward the
left hip
Which chamber experiences a maximum pressure of around 118 mm Hg during contraction
left ventricle
The pulmonary circuit involves blood flow from the heart to the
lungs
The heart is situated in the middle of the thoracic cavity in a region known as
mediastinum
What muscles, present in the ventricles, anchor the atrioventricular valves by tendon-like chords called chordae tendineae?
papillary muscle
Which of the following is NOT a population of pacemaker cells in the heart?
papillary muscles
What is found between the visceral pericardium and the parietal pericardium
pericardial fluid
During what phase of the action potential will calcium ions enter the contractile cell as potassium ions exit?
plateau phase
The degree of stretch experienced by the sarcomeres in the ventricle cells before they contract is called
preload.
What is the function of the valves in the
prevent backflow of blood through the hear
Which vessel is guarded by a semilunar valve at its base
pulmonary trunk
hich of the following does NOT return blood to the right atrium of the heart
pulmonary vein
hich of the following vessels carries oxygenated blood
pulmonary vein
What valve prevents the backflow of blood from the right ventricle into the right atrium
ricuspid valve
Blood in the right ventricle arrived from the
right atrium
What normally serves as the pacemaker of the entire heart
sinoatrial (SA) node
As ventricular systole begins, all four heart valves are closed during the
sovolumetric contraction phase.
The volume of blood pumped by each ventricle in one heartbeat is known as:
stroke volume (SV
What two values are needed in order to calculate cardiac output (CO) for a ventricle?
stroke volume (SV) and heart rate (HR)
Archie has a resting heart rate of 125 beats per minute. Classify his cardiac dysrhythmia.
tachycardia
As a result of the long refractory period in the contractile cell, cardiac muscle can NOT exhibit
tetany.
Predict the position of the valves during the ventricular ejection phase
the AV valves are shut while both semilunar valves are forced open
Afterload is described as:
the amount of blood that has drained into the ventricle by the end of the filling phase
What produces the "lub dub" heart sounds?
the vibrations of the ventricular and blood vessel walls when valves shut
Both the left and right atria receive blood from:
veins
During what phase does blood flow from the ventricles into the pulmonary trunk and aorta?
ventricular ejection phase
