Chapter 17: Blood (a&p2)

increased end diastolic volume

By what mechanism would an increase in venous return increase stroke volume?

80 milliliters *SV= EDV-ESV

Calculate the stroke volume (SV) of a patient whose EDV is 140 milliliters and whose ESV is 60 milliliters.

decreased stroke volume and no change in cardiac output

How would a decrease in blood volume affect both stroke volume and cardiac output?

increased contractility

How would an increase in the sympathetic nervous system increase stroke volume?

An elevated ST segment

If Jerome is having an acute MI, which ECG change would you expect to see?

increased heart rate and increased stroke volume

Which of the following would increase cardiac output to the greatest extent?

AV node

Which of these structures conduct(s) action potentials the slowest?

SA node

Which part of the intrinsic conduction system normally initiates the depolarizing impulse that causes a heartbeat?

Nitroglycerine, Supplemental Oxygen, and Pain medication

Which type of treatment might Jerome receive once the MI is confirmed?

pressure in the ventricles increases

The AV valves close when __________.

the pressure in the left ventricle falls below aortic pressure

The aortic valve closes when __________.

chord tendineae

The cusps of the atrioventricular valves attach to the papillary muscles via the __________.

delayed; before

The electrical impulse is __________ as it passes through the AV node, which permits the atria to contract __________ ventricles.

right atrium

The heart is actually (one, two, or three) pumps?

two pumps

The heart is actually (one, two, or three) pumps?

in the mediastinum

The heart is located _________.

the duration of atrial depolarization and AV node delay

The highlighted portion of this ECG trace corresponds to __________.

SA node

The main pacemaker of the heart is the __________.

End-diastolic Volume

The maximum amount of blood in the ventricles at the end of the ventricular filling phase is called __________.

Ca2+ influx

The plateau phase of the cardiac action potential is due to __________.

full depolarization phase.

The rapid influx of calcium ions into pacemaker cells creates a positive membrane potential inside the cell and is responsible for the:

a stronger contraction

According to the Frank-Starling law, a bigger preload will result in __________.

1.) SA Node 2.) Internodal Pathways 3.) AV Node 4.) AV Bundle 5.) Bundle Brances 6.) Purkinje Fibers

Arrange these elements of the intrinsic conduction system in the order that a depolarizing impulse travels during a normal heartbeat: Purkinje Fibers, Internodal pathways, SA node, Bundle branches, AV bundle, AV node

9.9 L/min

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.

1. )Bundle branches 2.) SA node 3.) AV node 4.) AV Bundle 5.) Internodal Pathways 6.) Purkinje Fibers

Match the cardiac components in the left column to the blanks near their functions on the right: 1.)_____ convey(s) the impulse down the inter ventricular septum 2.)____set(s) the pace for entire hear 3.)____ delay(s) occurs here while atria contract _____ electrical link(s) 4.)between atria and ventricles 5.)______ link(s) between the SA node and the AV node 6.)_____ convey(s) the impulse throughout the ventricular walls

left ventricle

Which chamber pumps oxygenated blood out the aorta to the systemic circuit?

pulmonary trunk

Blood that leaves the right ventricle enters the __________.

no change CO= HR*SV= 2HR* SV/2

How will the cardiac output change if you double the heart rate but reduce the stroke volume by one-half?

Closing of atrioventricular valves

Which of the following can be heard with a stethoscope most easily?

epinephrine and norepinephrine

Which of the following would increase heart rate?

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

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?

CONTRAACTILITY

An increase in sympathetic stimulation of the heart would increase stroke volume by increasing __________.

decreased ESV

Digoxin is a positive inotropic agent derived from the foxglove family of plants. Which of the following is an effect of digoxin?

decreased; decreased Blood loss will diminish the venous return and therefore decrease the preload. A decreased preload would cause a decrease in the stroke volume and therefore a decrease in the CO.

Hemorrhage would lead to a __________ preload and therefore __________ cardiac output.

so blood is forced upward, toward semilunar valves

The anatomy of the intrinsic conduction system causes contraction of the ventricles to begin at the apex and move superiorly. Why is this important?

B

The aortic valve opens at __________.

right coronary artery

The area shaded in orange receives blood supply from the __________.

closing of the atrioventricular valves

The beginning of the QRS complex of the electrocardiogram (ECG) immediately precedes which of the following events?

involve calcium voltage-gated channels

Unlike skeletal muscle action potentials, cardiac muscle action potentials __________.

isovolumetric contraction

Ventricular systole begins during the __________ phase of the cardiac cycle.

right ventricle

Which heart chamber pumps unoxygenated blood out the pulmonary trunk?

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

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?

look at picture

Jerome McCoy is a 62-year-old African American male. He came to the emergency room at approximately 3:00 a.m. this morning. He told the nurse that he didn't feel well last night and thought he had heartburn from the spicy dinner he had eaten. However, he woke up at 2:00 a.m. with an upset stomach and has a crushing and very painful sensation in his chest. This sensation radiates to his left arm and jaw. Jerome's blood pressure is 165/90 mmHg and his heart rate is 92 bpm. An acute myocardial infarction (MI) is suspected. An electrocardiogram (ECG) and blood work is done.

These proteins are normally found inside cardiac muscle cells and if present in the blood indicate damage to the cells.

Jerome also had blood work done to confirm the MI. The presence of troponin, or cardiac enzymes such as CK-MB, are a positive indicator of an MI. Why is their presence at higher levels in the blood indicative of an MI?

-Anticoagulants such as aspirin or heparin. They decrease the blood's ability to clot and are known as blood thinners (although they don't actually make the blood thinner). -Ca++ channel blockers to decrease the strength of the heart's contraction and to vasodilate blood vessels. -Cholesterol-lowering drugs to decrease the cholesterol and triglycerides in the blood. -Beta (β) blockers, which block the beta receptor in cardiac muscle to prevent heart rate from increasing. The heart beats slower and with more force.

Jerome will probably be placed on medication to decrease the workload of his heart and give it time to reset and recover. Remember that, once damaged, cardiac muscle does not repair via regeneration; it forms scar tissue that does not work normally. Which medication(s) might be prescribed to Jerome? Select all the correct answers. a.) Cholesterol-lowering drugs to decrease the cholesterol and triglycerides in the blood. Anti-anxiety medication such as valium to decrease Jerome's anxiety and fear of another heart attack. b.) Beta (β) blockers, which block the beta receptor in cardiac muscle to prevent heart rate from increasing. The heart beats slower and with more force. Anticoagulants such as aspirin or heparin. They decrease the blood's ability to clot and are known as blood thinners (although they don't actually make the blood thinner). c.) Ca++ channel blockers to decrease the strength of the heart's contraction and to vasodilate blood vessels. d.) Oxycodone, a pain killer to reduce the long-term pain from an MI.

1.) A 2.) D 3.) F 4.) B 5.) G 6.) H

Let's review the electrical events that occur during a heartbeat. Match each phase of the ECG in the figure with its description. 1.) ___: the atria depolarize 2.) ___: the action potential is in the AV node 3.) ___ the ventricles depolarize 4.) ___: the ventricles depolarize 5.) ___the ventricles are contracting 6.) ___ the time from ventricular depolarization to the end of ventricular depolarization, including ventricular 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

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

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

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.

Acetylcholline

Which of the following is a chronotropic agent that decreases heart rate?

Increased contractility

Which of the following is appropriate for the box identified with a question mark?

1.) Rapid depolarization phase: voltage-gated Na+ channels activate and Na+ enter, rapidly depolarizing the membrane 2.) Initial Repolarization phase: Na+ channels are inactivated and some K+ channels open; K+ leak out, causing a small initial depolarization 3.) Plateau phase: Ca2+ channels open and Ca2+ enters as K+ exit, prolonging the depolarization 4.) Repolarization phase: Na+ and Ca2+ channels close as K+ continue to exit, causing repolarization

Rank from the first to the last steps to describe the correct order of events of a cardiac contractile cell action potential. Refer to the graph of a contractile cell action potential as you rank the events

1.) Slow initial depolarization 2.) Full Depolarization phase 3.) Repolarization phase 4.) Minimum potential phase

Rank from the first to the last steps to describe the correct order of events of a pacemaker cell action potential. Refer to the graph of a pacemaker cell action potential as you rank the events.

left ventricle

The cardiac chamber with the thickest wall is the __________.

ventricles

The chambers that have just emptied when the second heart sound is heard are the __________.

A

The main negative chronotropic effect on the heart is exerted by __________.

visceral pericardium

The visceral pericardium is also known as the __________.

left atrium

Which heart chamber receives blood from the pulmonary veins?

the atrioventricular valves open.

Which of the following events will immediately follow the phase of the cardiac cycle depicted in the figure?