Cardiovascular

Front 1

Which of these structures is NOT found in the mediastinum?

A)esophagusB)heartC)lungD)thymus glandE)trachea

Back 1

Correct Answer: The esophagus, heart, thymus gland, and trachea are found in the mediastinum. The lungs are not found in the mediastinum.

Front 2

Which of these descriptions of the heart's location is correct?

A)The heart lies obliquely in the mediastinum.B)Its base is directed anteriorly and slightly superiorly.C)Its apex is directed posteriorly and slightly inferiorly.D)Two-thirds of the heart's mass lies to the right of the midline of the sternum.E)all of these

Back 2

Correct Answer: The heart lies obliquely in the mediastinum.

Front 3

The epicardiumA)is also known as the parietal pericardium.B)is a layer of cardiac muscle.C)is the visceral pericardium.D)lines the heart chambers.E)is the pacemaker of the heart.

Back 3

Correct Answer: The epicardium is a thin layer of serous membrane covering the heart surface that is also known as the visceral pericardium.

Front 4

The heart valves have a double layer of __________ with a layer of __________ in between.

A)epicardium, myocardiumB)epicardium, endocardiumC)myocardium, endocardiumD)endocardium, connective tissueE)connective tissue, epicardium

Back 4

Correct Answer: The heart valves have a double layer of epicardium with a layer of connective tissue between.

Front 5

Musculi pectinati are found in the __________ ; trabeculae carneae are found in the __________ .A)auricles, auriclesB)auricles, ventriclesC)ventricles, auriclesD)ventricles, ventricles

Back 5

Correct Answer: Musculi pectinati are found in the auricles; trabeculae carneae are found in the ventricles.

Front 6

Which of these structures deliver(s) blood to the left atrium?A)coronary sinusB)superior vena cavaC)inferior vena cavaD)pulmonary veinsE)pulmonary arteries

Back 6

Correct Answer: The pulmonary veins deliver oxygenated blood to the left atrium from the lungs.

Front 7

The anterior interventricular artery is a branch of theA)left pulmonary artery.B)right pulmonary artery.C)left coronary artery.D)right coronary artery.E)aorta.

Back 7

Correct Answer: The anterior interventricular artery is a branch of the left coronary artery.

Front 8

Strong connective tissue strings that are attached to papillary muscles and to the cusps of the atrioventricular valves areA)musculi pectinati.B)chordae tendineae.C)trabeculae carneae.D)the skeleton of the heart.E)the interventricular septum.

Back 8

Correct Answer: Chordae tendineae are the connective tissue strings that attach to the papillary muscles and the atrioventricular valves at the cusps.

Front 9

Given these valves: 1. aortic semilunar valve 2. bicuspid (mitral) valve 3. pulmonary semilunar valve 4. tricuspid valve. Arrange them in the order in which an erythrocyte would pass through them after returning to the heart from the left arm.A)1,2,3,4B)2,3,1,4C)3,1,2,4D)3,4,2,1E)4,3,2,1

Back 9

Correct Answer: The correct order would be 4,3,2,1. An erythrocyte would pass through the tricuspid valve first, the pulmonary semilunar valve second, the bicuspid valve third, and finally through the aortic semilunar.

Front 10

The skeleton of the heartA)electrically insulates the atria from the ventricles.B)is composed of bones and cartilage.C)is the location of the pacemaker.D)is composed of calcified cardiac muscle.

Back 10

Correct Answer: The skeleton of the heart, which is composed of fibrous connective tissue, insulates the atria from the ventricles.

Front 11

Which of these structures is NOT present in cardiac muscle cells?A)desmosomesB)gap junctionsC)smooth sarcoplasmic reticulumD)terminal cisternaeE)transverse (T) tubules

Back 11

Correct Answer: Terminal cisternae are not found in cardiac muscle cells.

Front 12

The group of modified cardiac muscle cells that delays action potentials between the atria and the atrioventricular bundle is called theA)Purkinje fibers.B)SA node.C)bundle branches.D)AV node.E)apex.

Back 12

Correct Answer: The AV node is the group of modified cardiac muscles cells that delay the action potential between the atria and the ventricles. The delay is roughly .11 seconds as action potentials reach the AV node and then finally pass to the AV bundle.

Front 13

If the SA node becomes damaged and nonfunctional, which of these is the most likely to occur?A)The heart will stop.B)The ventricles will contract, but the atria will stop.C)Another part of the heart, possibly the AV node, will become the pacemaker.D)The heart will beat faster.E)The atria will keep contracting, but the ventricles will stop.

Back 13

Correct Answer: The heart can continue to function, but the pacing will have to be taken over by another pacer, possibly the AV node.

Front 14

Which of these statements concerning cardiac muscle is correct?A)Cardiac muscle has more sarcoplasmic reticulum than skeletal muscle.B)Cardiac muscle has a prolonged period of slow repolarization called the plateau phase.C)Cardiac muscle has a shorter refractory period than skeletal muscle.D)Depolarization of cardiac muscle occurs when K+ and Na+ diffuse into the cell.E)all of these are correct

Back 14

Correct Answer: Cardiac muscle has a prolonged period of slow repolarization called the plateau phase occurring as voltage-gated Ca2+ ion channels open and Ca2+ ion movement into cardiac cells counteracts K+ ion movement out of cardiac muscle cells.

Front 15

Action potentials pass rapidly from one cardiac muscle cell to another because ofA)intercalated disks and numerous gap junctions.B)large nerves with branches going to each cardiac muscle cell.C)the large voltage of cardiac action potentials.D)the plateau phase of the action potential.E)open Ca2+ channels.

Back 15

Correct Answer: The presence of intercalated disks and gap junctions allows action potentials to be propagated from one muscle cell to another.

Front 16

The depolarization phase of the cardiac muscle action potential occurs whenA)voltage-gated Ca2+ ion channels open.B)voltage-gated K+ ion channels open.C)voltage-gated Na+ ion channels open.D)both b and c

Back 16

Correct Answer: Depolarization of cardiac muscle occurs when Na+ ions diffuse into the cell as voltage-gated Na+ ion channels open.

Front 17

Early repolarization of cardiac muscle cells occurs whenA)voltage-gated Ca2+ ion channels open.B)voltage-gated K+ ion channels open.C)voltage-gated Na+ ion channels close.D)both b and c

Back 17

Correct Answer: Early repolarization of cardiac muscle cells occurs when voltage-gated Na+ ion channels close and voltage-gated K+ ion channels open.

Front 18

Which of these conditions occur in the cardiac muscle cell during the plateau phase?A)voltage-gated Ca2+ ion channels are openB)voltage-gated K+ ion channels are openC)voltage-gated Na+ ion channels are closedD)all of these

Back 18

Correct Answer: During the plateau phase voltage-gated Ca2+ and K+ ion channels are open, and voltage-gated Na+ ion channels are closed.

Front 19

Unlike other cardiac muscle cells, the movement of __________ into the pacemaker cells is primarily responsible for the depolarization phase of the action potential.A)Ca2+ ionsB)K+ ionsC)Na+ ionsD)Cl- ions

Back 19

Correct Answer: The movement of Ca2+ ions into the pacemaker cells is primarily responsible for the depolarization phase of the action potential.

Front 20

Which of these conditions results in a prepotential in pacemaker cells?A)Na+ ions move into the cell through specialized Na+ ion channels.B)Membrane permeability to K+ ions increases.C)Voltage-gated Ca2+ ion channels close.D)all of these are correct

Back 20

Correct Answer: The prepotential in pacemaker cells is produced when Na+ ions move into the cell through specialized non-gated Na+ ion channels.

Front 21

In an EKG, the P wave representsA)depolarization of the atria.B)repolarization of the atria.C)depolarization of the ventricles.D)repolarization of the ventricles.

Back 21

Correct Answer: The P wave on an EKG represents atrial depolarization.

Front 22

During the QT interval of the EKG, theA)atria contract and begin to relax.B)atria relax.C)ventricles contract and begin to relax.D)ventricles relax.

Back 22

Correct Answer: During the QT interval of the EKG, the ventricles contract and begin to relax.

Front 23

Which of these conditions is most likely to cause bradycardia?A)ectopic action potentials in the atriaB)damage to the tricuspid valveC)excessive sympathetic stimulationD)excessive parasympathetic stimulationE)too much coffee

Back 23

Correct Answer: Excessive parasympathetic stimulation is most likely to cause bradycardia.

Front 24

During the period of ejection in the cardiac cycle, the atrioventricular valves are __________ and the semilunar valves are __________ .A)closed, closedB)closed, openC)open, closedD)open, open

Back 24

Correct Answer: During the ejection period of the cardiac cycle, the AV valves are closed, preventing backflow of blood into the atria, and the semilunar valves are open, allowing blood to flow into the pulmonary trunk and aorta.

Front 25

Blood flows neither into nor out of the ventricles duringA)the period of isovolumic contraction.B)the period of isovolumic relaxation.C)systole.D)diastole.E)both a and b

Back 25

Correct Answer: During the periods of isovolumic contraction and isovolumic relaxation, the AV and semilunar valves are shut, preventing blood from entering or leaving the ventricles.

Front 26

At the end of __________ , the ventricles are 70% filled.A)active ventricular fillingB)passive ventricular fillingC)ventricular diastoleD)ventricular systoleE)atrial systole

Back 26

Correct Answer: At the end of passive ventricular filling, the ventricles are 70% filled.

Front 27

The average end-diastolic volume of the ventricles is about __________ , whereas the end-systolic volume is about __________ .A)125 mL, 55 mLB)125 mL, 0 mLC)0 mL, 55 mLD)0 mL, 125 mLE)55 mL, 125 mL

Back 27

Correct Answer: The average end-diastolic volume is 125 ml; the average end-systolic volume is 55 ml.

Front 28

During the period of ejection, the left ventricular pressure reaches a high point of approximatelyA)20 mm Hg.B)60 mm Hg.C)80 mm Hg.D)100 mm Hg.E)120 mm Hg.

Back 28

Correct Answer: 120 mm Hg is the peak pressure generated at the left ventricle during the period of ejection.

Front 29

The second heart sound, described as "dupp" is actually the sound of theA)atria contracting.B)ventricles contracting.C)atrioventricular valves closing.D)semilunar valves closing.E)heart slapping the liver.

Back 29

Correct Answer: The second heart sound (S2) is the sound produced when the semilunar valves close.

Front 30

If the heart rate for a patient is 80 bpm, and her stroke volume is 70 mL/beat, then her cardiac output isA)O.87 mL/minB)1.1 mL/min.C)10 mL/min.D)56 mL/min.E)5600 mL/min

Back 30

Correct Answer: Because cardiac output is equal to stroke volume multiplied by heart rate, this patient's cardiac output would be 5600 ml/min.

Front 31

PreloadA)is the extent to which the ventricular walls are stretched.B)if increased, causes a decrease in cardiac output.C)is the pressure in the aorta which contracting ventricles must overcome.D)is part of the extrinsic regulation of the heart.E)all of these

Back 31

: Correct Answer: Preload is the extend to which ventricular walls are stretched with blood.

Front 32

Increased venous return to the heart causes increasedA)stroke volume.B)preload.C)cardiac output.D)force of contraction.E)all of these

Back 32

Correct Answer: Increased venous return to the heart increases preload which increases stroke volume, the force of contraction, and consequently, cardiac output.

Front 33

Parasympathetic nerve fibersA)are carried to the heart through the Accessory nerve (XI).B)extend to terminal ganglia within the wall of the heart.C)release the neurotransmitter norepinephrine.D)if stimulated, result in an increased heart rate.E)if stimulated, greatly increase stroke volume.

Back 33

Correct Answer: Parasympathetic nerve fibers do extend to terminal ganglia within the wall of the heart.

Front 34

When normal arterial blood pressure decreases, baroreceptors cause a response thatA)decreases heart rate.B)decreases stroke volume.C)returns blood pressure to normal.D)results in parasympathetic stimulation of the heart.E)all of these

Back 34

Correct Answer: When normal arterial blood pressure decreases, baroreceptors cause a response that returns blood pressure to normal.

Front 35

If blood pH decreases and blood carbon dioxide increases,A)heart rate increases.B)stroke volume decreases.C)increased parasympathetic stimulation of the heart occurs.D)the change is detected by chemoreceptors in the pulmonary arteries.E)all of these

Back 35

Correct Answer: If blood pH decreases and blood carbon dioxide increases, heart rate will increase.

Front 36

Increased sympathetic stimulation of the heartA)increases the force of ventricular contraction.B)opens a larger number of calcium slow channels.C)increases the heart rate.D)increases cardiac output.E)all of these

Back 36

Correct Answer: Increased sympathetic stimulation of the heart increases the force of ventricular contraction, opens larger numbers of calcium slow channels, and increases heart rate and cardiac output.

Front 37

Generally, an increase in extracellular Ca2+ ions causes __________ force of contraction, and __________ heart rate.

A)decreased, decreasedB)decreased, increasedC)increased, decreasedD)increased, increased

Back 37

Correct Answer: An increase in extracellular Ca2+ ions causes increased force of contraction, and decreased heart rate.

Front 38

Excess K+ ions in cardiac tissue cause heart rate and stroke volume to __________ and decreased extracellular K+ ions result in a __________ in heart rate.A)decrease, decreaseB)decrease, increaseC)increase, decreaseD)increase, increaseE)be unchanged, increase

Back 38

Correct Answer: Excess K+ ions in cardiac tissue cause heart rate and stroke volume to decrease and decreased extracellular K+ ions result in a decrease in heart rate.