Chapter 17 Heart Mastering
Place the following parts of the cardiac conduction system in the order in which they transmit the action potential. 1. atrioventricular (AV) bundle 2. Purkinje fibers 3. sinoatrial (SA) node 4. right and left bundle branches 5. contractile cells of cardiac muscle tissue 6. atrioventricular (AV) node
3, 6, 1, 4, 2, 5
Calculate the end-systolic volume (ESV) if the end-diastolic volume (EDV) in a resting heart is 110 ml and stroke volume (SV) is 70 ml.
40 ml
The amount of blood remaining in each ventricle at the end of the ventricular ejection phase is normally about:
50 ml
The aortic valve opens at __________.
B
The right side of the heart pumps deoxygenated blood into __________.
B - pulmonary arteries
The parietal pericardium is labeled __________.
C
The ventricular ejection phase of the cardiac cycle is labeled __________.
C
What action causes the first heart sound heard through a stethoscope?
Closing of the atrioventricular valves
A damaged atrioventricular (AV) bundle or atrioventricular (AV) node will primarily affect the length of the:
P-R interval.
Which part of the electrocardiogram (ECG) would most be affected by abnormally slow depolarization of the ventricles?
QRS wave
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
The main pacemaker of the heart is the __________.
SA node
Which of the following happens immediately after the P wave?
The atria contract
Determine the impact if the connection between the sinoatrial (SA) node and the atrioventricular (AV) node becomes blocked.
The ventricles will contract more slowly.
What activity is occurring in the heart during the Q-T interval on an electrocardiogram (ECG)?
The ventricular cells are undergoing action potentials.
Pressure in the aorta is greater than pressure in the pulmonary trunk; therefore, the left ventricle has to generate a greater pressure than the right ventricle in order to eject blood from the heart.
True
Which of the following decreases heart rate?
acetylcholine
The right and left coronary arteries receive blood from the:
aorta
Where should the left ventricle send blood?
aorta
Which vessel supplies the systemic circuit with oxygenated blood?
aorta
The P wave on an electrocardiogram (ECG) represents the depolarization of cells in the:
atria
What is NOT part of the cardiac conduction system?
atrioventricular (AV) valve
The electrical impulse is __________ as it passes through the AV node, which permits the atria to contract __________ ventricles.
delayed; before
The right side of the heart receives:
deoxygenated blood from the systemic circuit. Submit
Coronary circulation involves the delivery of oxygenated blood to the:
heart
The apex of the heart is __________.
inferior
What characteristic differentiates cardiac muscle cells from skeletal muscle cells?
intercalated discs
As ventricular systole begins, all four heart valves are closed during the:
isovolumetric contraction phase.
Which heart chamber receives blood from the pulmonary veins?
left atrium
The cardiac chamber with the thickest wall is the __________.
left ventricle
Which chamber pumps oxygenated blood out the aorta to the systemic circuit?
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 the:
mediastinum
The cells that rhythmically and spontaneously generate action potentials in the heart are called __________.
pacemaker cells
What muscles, present in the ventricles, anchor the atrioventricular valves by tendon-like chords called chordae tendineae?
papillary muscles
During what part of the action potential will calcium ions enter the contractile cell?
plateau phase
The degree of stretch experienced by the sarcomeres in the ventricle cells before they contract is called:
preload
The AV valves close when __________.
pressure in the ventricles increases
What is the function of the valves in the heart?
prevent backflow of blood through the heart
Which vessel is guarded by a semilunar valve at its base?
pulmonary trunk
Which of the following vessels carries oxygenated blood?
pulmonary vein
What vessel(s) deliver oxygenated blood to the left atrium?
pulmonary veins
Blood in the right ventricle arrived from the:
right atrium
Which chamber receives blood from the superior and inferior vena cavae?
right atrium
The area shaded in orange receives blood supply from the __________.
right coronary artery
Which heart chamber pumps unoxygenated blood out the pulmonary trunk?
right ventricle
What normally serves as the pacemaker of the entire heart?
sinoatrial (SA) node
What two values are needed in order to calculate cardiac output (CO) for a ventricle?
stroke volume (SV) and heart rate (HR)
The vessels that deliver oxygen to the tissues of the body are part of the __________.
systemic circuit
The highlighted portion of this ECG trace corresponds to __________.
the duration of atrial depolarization and AV node delay
What valve prevents the backflow of blood from the right ventricle into the right atrium?
tricuspid valve
Blood in the right atrium should travel next past the:
tricuspid valve and into the right ventricle.
The left ventricle has greater muscle mass than the right ventricle since it pumps against greater resistance.
true
The heart is actually (one, two, or three) pumps?
two pumps
Both the left and right atria receive blood from:
veins
Blood from the systemic circuit returns to the heart via the __________.
venae cavae
The chambers that have just emptied when the second heart sound is heard are the __________.
ventricles
During what phase does blood flow from the ventricles into the pulmonary trunk and aorta?
ventricular ejection phase
The T wave of an ECG corresponds to __________.
ventricular repolarization
