Upgrade to remove ads
Only $35.99/year

DSM Chapter 17

Terms in this set (75)

what structure attaches the cusps of the atrioventricular valves to the papillary muscles?
chordae tendiae
Which coronary artery supplies the left atrium and parts of the left ventricle?
circumflex artery
Which of the following blood vessels are associated with the coronary sinus?
great cardiac
Which of the following is not a risk factor for coronary artery disease or myocardial ischemia?
low blood pressure
Which of the following blood vessels is not a great blood vessel of the heart?
pulmonary arteries
What are the three layers of the heart wall from superficial to deep?
epicardium, myocardium, and endocardium
Oxygenated blood is delivered to the left atrium through the ____________.
pulmonary veins
Blood in the right atrium should travel next past the ________.
tricuspid valve and the right ventricle
Which of the following statements best describes how coronary artery anastomoses might help a patient with coronary artery disease?
They provide alternate routes of blood flow when a vessel is blocked.
Which of the following vessels carries oxygenated blood?
pulmonary vein
Which of the following structures is associated with the atria?
pectinate muscles
The right side of the heart receives ________.
deoxygenated blood from the systemic circuit
What blood vessels do ventricles always pump blood into?
arteries
The visceral pericardium is the same as the ________.
epicardium
Which cardiac chamber has the thickest wall?
left ventricle
Which vessel is guarded by a semilunar valve at its base?
pulmonary trunk
Where does the left ventricle send blood?
aorta
What is the most superficial layer of the pericardial sac?
fibrous pericardium
Which of the following statements best describes the apex of the heart?
inferior tip of the heart and points toward the left side
What might happen if the papillary muscles and/or chordae tendineae stopped functioning?
blood would leak back into the atria from the ventricles
What valve prevents the backflow of blood from the right ventricle into the right atrium?
right atrioventricular valve (tricuspid valve)
What is the function of the valves in the heart?
prevent backflow of blood through the heart
Which opening in the interatrial septum of the fetal heart connects the right and left atrium?
foramen ovale
The mitral valve is the clinical name for the ______________.
bicuspid valve
What condition results from excess fluid in the pericardial cavity compressing the heart and reducing the capacity of the ventricles to fill with blood?
cardiac tamponade
Which of the following functions is not associated with the heart?
to increase the rate at which erythrocytes are formed
Both the left and right atria receive blood from ________.
veins
The right and left atria depolarize and contract following the arrival of the action potential from the __________.
sinoatrial (SA) node
What activity is occurring in the heart during the Q-T interval on an electrocardiogram (ECG)?
the ventricular cells are undergoing action potentials
Which electrocardiogram (ECG) finding can be used to measure heart rate?
R-R interval
What percentage of the total number of cardiac muscle cells are pacemaker cells?
1%
Which of the following statements describes the total refractory period of cardiac muscle?
it is longer than the total refractory period for skeletal muscles
Which of the following cardiac dysrhythmias is immediately life-threatening and manifests on the electrocardiogram (ECG) with chaotic activity?
ventricular fibrillation
What allows the atria and ventricles to depolarize and contract separately?
atrioventricular (AV) node delay
The P wave on an electrocardiogram (ECG) represents the depolarization of cells in the __________.
atria
Looking in a microscope, what are the visible structures that join cardiac muscle cells?
intercalated discs
Autorhythmicity in the heart is a function of ________.
cardiac pacemaker cells
During what part of the action potential will calcium ions enter the contractile cell?
plateau phase
Which of the following pacemaker cell populations has the slowest intrinsic rate of depolarization at about 20 times per minute?
purkinje fiber system
Which of the following structural components is only found in cardiac muscles?
intercalated discs
What normally serves as the pacemaker of the entire heart?
sinoatrial (SA) node
What kind of ion channels are unique to pacemaker cells?
HCN channels
A damaged atrioventricular (AV) bundle or AV node will primarily affect the length of the __________.
P-R interval
Which of the following ion channels are time-gated closing channels?
calcium ion channels
What part of an electrocardiogram (ECG) represents ventricular repolarization?
T wave
Which wave on the electrocardiogram (ECG) represents ventricular depolarization?
QRS complex
Which of the following cell populations does not spontaneously generate action potentials in the cardiac conduction system?
contractile cells
What obscures atrial repolarization on an electrocardiogram (ECG)?
QRS complex
What is a contractile cell with a membrane potential of 0 mV experiencing?
plateau phase
What cardiac dysrhythmia does a patient have with a resting heart rate of 50 beats per minute?
bradycardia
What provides a graphic representation of all the action potentials occurring in the heart?
electrocardiogram
What is initiated by a rapid influx of sodium ions into contractile cells creating a positive membrane potential inside the cell?
rapid depolarization phase
Which of the following events is not part of the cardiac cycle?
atrial contraction phase
What percentage of atria blood flows passively into the ventricles?
80%
What is the volume of blood pumped out by one ventricle per heart beat?
stroke volume
Which hormone decreases cardiac output by decreasing blood volume and preload?
atrial natriuretic peptide
Approximately how much blood is pumped from each ventricle during the ventricular ejection phase?
70 ml
What largely determines preload?
end-diastolic volume (EDV)
Which chamber generates the highest pressure during systole?
left ventricle
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
During what phase is the S1 heart sound first heard?
isovolumetric contraction phase
Which of the following paths does an action potential in the heart normally take?
SA node atrial contractile cells AV node where it is delayed AV bundle right and left bundle branches Purkinje fibers ventricular contractile cells
Approximately how much blood is pumped from each ventricle during the ventricular ejection phase?
70 ml
Which cranial nerves have a negative chronotropic effect on heart rate?
vagus nerve (CN X)
Which wave on the electrocardiogram (ECG) corresponds with the ventricular filling phase of the cardiac cycle?
P wave
High-pressured blood in the ventricles ________.
forces the semilunar valves open
What two values are needed to calculate cardiac output (CO) for a ventricle?
stroke volume (SV) and heart rate (HR)
Which of the following hormones decrease cardiac output by decreasing blood volume and preload?
atrial natriuretic peptide
Inotropic agents affect __________.
contractility
Which of the following chemical messengers decreases heart rate?
acetylcholine
Which of the following terms refers to the force the ventricles must overcome to eject blood into their respective arteries?
afterload
According to the Frank-Starling law, a bigger preload will result in __________.
a stronger contraction
The degree of stretch experienced by the sarcomeres in the ventricle cells before they contract is called __________.
preload
Which of the following factors would increase cardiac output to the greatest extent?
increased heart rate and increased stroke volume
Which of the following events can be heard most easily with a stethoscope?
closing of atrioventricular valves
Other sets by this creator