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