A&P chapter 18

Which of these structures conduct(s) action potentials the slowest? A) Bundle branches B) AV bundle C) AV node D) Purkinje fibers

C) AV node

Chest pain (angina) is associated with myocardial _____________. A) infarction. B) necrosis. C) ischemia. D) hemorrhage

C) ischemia.

Arrange these elements of the intrinsic conduction system in the order that a depolarizing impulse travels during a normal heartbeat.

1) SA node 2) Internodal pathways 3) AV node 4) AV bundle 5) Bundle branches 6) Purkinje fibers

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 HINT: (HR * SV= CO) A) 9.9 L/min B) 14.0 L/min C) 20.0 L/min D) 34.0 L/min

A) 9.9 L/min

Which of the following can be heard with a stethoscope most easily? A) Closing of atrioventricular valves B) Contraction of atria C) Blood flow into aorta D) Isovolumetric contraction

A) Closing of atrioventricular valves

Which part of the intrinsic conduction system normally initiates the depolarizing impulse that causes a heartbeat? A) SA node B) AV bundle C) AV node D) Internodal pathway

A) SA node

Which of the following best describes the arterial lesion associated with atherosclerosis? A) atheroma. B) aneurysm. C) hemmorhage. D) dissection.

A) atheroma.

The anatomy of the intrinsic conduction system causes contraction of the ventricles to begin at the apex and move superiorly. Why is this important? A) so the atria can finish contracting before the ventricles contract B) so blood is forced upward, toward the semilunar valves C) because the Purkinje fibers conduct action potentials away from the heart apex D) because the AV bundle is the only electrical connection between the atria and the ventricles

B) so blood is forced upward, toward the semilunar valves

What percentage of heart attack patients do not experience chest pain? A) 8%. B) 10%. C) 20%. D) 33%.

D) 33%

What percentage of myocardial infarction patients demonstrate arrhythmias? A) 40%. B) 60%. C) 75%. D) 90%.

D) 90%.

An increase in sympathetic stimulation of the heart would increase stroke volume by increasing __________. A) end diastolic volume B) heart rate C) end systolic volume D) contractility

D) contractility

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? A) no change in cardiac output, decreased heart rate, increased stroke volume B) decrease in cardiac output, decreased heart rate, decreased stroke volume C) increase in cardiac output, increased heart rate, increased stroke volume D) no change in cardiac output, increased heart rate, decreased stroke volume

D) no change in cardiac output, increased heart rate, decreased stroke volume

What structure left in place when the angioplasty ballon is deflated/removed to restore coronary artery blood flow? A) atheroma. B) ballon. C) catheter. D) stent.

D) stent.

Predict the changes in heart rate, stroke volume, and cardiac output for each of the following conditions by filling out the table below. Drag the appropriate labels to their respective targets.

Increased sympathetic activity: Increase HR, SV, CO Increase Preload: No change in HR, increase SV and CO Increased exercise: Increase HR, SV, CO Increase contractility: No change in HR, increase SV and CO

The beginning of the QRS complex of the electrocardiogram (ECG) immediately precedes which of the following events? A) closing of the atrioventricular valves B) atrial contraction C) closing of the semilunar valves D) blood ejection from the ventricles

A) closing of the atrioventricular valves

A coronary artery bypass (CABG): A) shunts blood beyond coronary blockage. B) implants an artificial pacemaker into the ventricular wall. C) repositions the aortic arch so it can feed into the coronary arteries. D) reestablishes blood flow proximal to the blockage.

A) shunts blood beyond coronary blockage.

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? A) Action potentials are not delayed sufficiently at the AV node. B) Action potentials propagate into the ventricles before the contractile cells have repolarized from the previous heartbeat. C) Purkinje fibers initiate spontaneous action potentials, which cause the ventricles to contract early. D) Spontaneous action potentials in the SA node overlap such that the repolarizing phase of one action potential cancels out the depolarizing phase of the next.

C) Purkinje fibers initiate spontaneous action potentials, which cause the ventricles to contract early.

Daily use of low-dose aspirin helps to reduce: A) blood cholesterol. B) hypertension. C) blood clots. D) angina.

C) blood clots.

What heart diagnostic procedure uses sound waves to create a moving picture of the heart? A) CT/MRI angiography. B) electrocardiogram C) echocardiogram. D) electron-beam computed tomography (EBCT).

C) echocardiogram.

Match the term in the left column to the blanks near their definition on the right. 1. ________: the number of heart beats per minute 2. ________: the volume of blood in one ventricle before contraction 3. ________: the volume of blood per heart beat pumped out by one ventricle 4. ________: the volume of blood per minute flowing into one atrium 5. ________: the volume of blood per minute pumped out by one ventricle 6. ________: the volume of blood in one ventricle after contraction

Match the term in the left column to the blanks near their definition on the right. 1. Heart rate (HR): the number of heart beats per minute 2. End diastolic volume (EDV): the volume of blood in one ventricle before contraction 3. Stroke volume (SV): the volume of blood per heart beat pumped out by one ventricle 4. Venous return (VR): the volume of blood per minute flowing into one atrium 5. Cardiac output (CO): the volume of blood per minute pumped out by one ventricle 6. End systolic volume (ESV): the volume of blood in one ventricle after contraction

Which of the following is a reversible event? A) hypoxia. B) occlusion. C) necrosis. D) coagulation cascade.

A) hypoxia.

Angioplasty is used to: A) remove arterial blockage. B) repair torn arteries. C) detect abnormal heart rhythms. D) inhibit plaque formation post-heart attack

A) remove arterial blockage.

1. ________: Delay(s) occurs here while atria contract 2. ________: Set(s) the pace for the entire heart 3. ________: Link(s) between the SA node and AV node 4. ________ : Electrical link(s) between atria and ventricles 5. ________: Convey(s) the impulse throughout the ventricular walls 6. ________: Convey(s) the impulse down the interventricular septum

1. AV node: Delay(s) occurs here while atria contract 2. SA node: Set(s) the pace for the entire heart 3. Internodal pathways: Link(s) between the SA node and AV node 4. AV bundle : Electrical link(s) between atria and ventricles 5. Purkinje fibers: Convey(s) the impulse throughout the ventricular walls 6. Bundle branches: Convey(s) the impulse down the interventricular septum