Anatomy 2 Chapter 18
Chest pain (angina) is associated with myocardial _____________.
ischemia
What percentage of heart attack patients do not experience chest pain?
33%
Calculate the cardiac output if heart rate (HR) is 90 beats per minute, stroke volume (SV) is 110 ml/beat, end diastolic volume (EDV) is 140 ml, and end systolic volume (ESV) is 30 ml.
9.9 L/min
What percentage of myocardial infarction patients demonstrate arrhythmias?
90%
Which of these structures conduct(s) action potentials the slowest?
AV node
Which of the following can be heard with a stethoscope most easily?
Closing of atrioventricular valves
bundle branches
Convey(s) the impulse down the interventricular septum
Purjinke fibers
Convey(s) the impulse throughout the ventricular walls
AV node
Delay(s) occurs here while atria contract
AV bundle
Electrical link(s) between atria and ventricles
internodal pathways
Link(s) between the SA node and AV node
A person notices his or her heart beat because he or she senses blood being pumped by the heart. Excessive caffeine intake can lead to irregular heart rhythms (arrhythmias) that patients perceive as "skipped beats." Given that caffeine is a stimulant, which of the following mechanisms best explains the reason for the feeling that the heart skipped a beat?
Purkinje fibers initiate spontaneous action potentials, which cause the ventricles to contract early.
Which part of the intrinsic conduction system normally initiates the depolarizing impulse that causes a heartbeat?
SA node
Arrange these elements of the intrinsic conduction system in the order that a depolarizing impulse travels during a normal heartbeat.
SA node Internal pathways AV node AV bundle Bundle branches Purkinje fibers
SA node
Set(s) the pace for the entire heart
Which of the following best describes the arterial lesion associated with atherosclerosis?
atheroma
Daily use of low-dose aspirin helps to reduce:
blood clots
The beginning of the QRS complex of the electrocardiogram (ECG) immediately precedes which of the following events?
closing of the atrioventricular valves
An increase in sympathetic stimulation of the heart would increase stroke volume by increasing __________.
contractility
What heart diagnostic procedure uses sound waves to create a moving picture of the heart?
echocardiogram
Which of the following is a reversible event?
hypoxia
As part of a blood drive on campus for the American Red Cross, you and your friends have just donated 500 ml of blood. You are now relaxing at the student lounge, waiting for A&P lab to begin. Unfortunately, even though you are thirsty, you haven't bothered to buy yourself a drink. Other than a little soreness of the skin and tissue around your median cubital vein, you feel fine. How has your 500 ml decrease in blood volume most likely affected your cardiac output, heart rate, and stroke volume?
no change in cardiac output, increased heart rate, decreased stroke volume
Angioplasty is used to:
remove arterial blockage.
A coronary artery bypass (CABG):
shunts blood beyond coronary blockage.
The anatomy of the intrinsic conduction system causes contraction of the ventricles to begin at the apex and move superiorly. Why is this important?
so blood is forced upward, toward the semilunar valves
What structure left in place when the angioplasty ballon is deflated/removed to restore coronary artery blood flow?
stent
heart rate
the number of heart beats per minute
end systolic volume
the volume of blood in one ventricle after contraction
end diastolic volume
the volume of blood in one ventricle before contraction
stroke volume
the volume of blood per heart beat pumped out by one ventricle
venous return
the volume of blood per minute flowing into one atrium
cardiac output
the volume of blood per minute pumped out by one ventricle