Bio 152 Test 2.2

Front 1

Vagal tone refers to the: A. decreasing of the heart rate below its inherent rhythm by parasympathetic stimulation. B. decreasing of the heart rate below its inherent rhythm by sympathetic stimulation. C. increasing of the heart rate above its inherent rhythm by sympathetic stimulation. D. increasing of the heart rate above its inherent rhythm by parasympathetic stimulation.

Back 1

A

Front 2

What is the sequence of events in the transmission of an impulse through the heart muscle? a: AV node b: AV bundle c: SA node d: Through the atria e: Through the ventricles f: Bundle branches g: Purkinje fibers A. c, d, a, b, f, g, e B. d, b, a, c, f, g, e C. b, a, d, c, f, g, e D. f, g, d, c, b, a, e E. c, d, a, f, b, g, e

Back 2

A

Front 3

At the AV node of the conduction system, the action potential is: A. rapidly advanced due to the cells being large and well connected by gap junctions. B. rapidly advanced due to the cells being small and well insulated by myelin. C. delayed due to the cells being small and having few gap junctions. D. delayed due to the cells being large and having many leakage channels.

Back 3

C

Front 4

The membrane of a contractile cardiac muscle cell contains: A. fast voltage-gated sodium channels and fast voltage-gated calcium channels. B. fast voltage-gated sodium channels and slow voltage-gated calcium channels. C. slow voltage-gated sodium channels and slow voltage-gated calcium channels. D. slow voltage-gated sodium channels and fast voltage-gated calcium channels.

Back 4

B

Front 5

The membrane of a contractile cardiac muscle cell contains: A. no calcium pumps. B. calcium pumps that move calcium out of the cell. C. calcium pumps that move calcium into the cell. D. calcium pumps that open and allow calcium to diffuse down its concentration gradient to reach equilibrium.

Back 5

B

Front 6

During the plateau phase of a cardiac muscle cell's action potential, the membrane stays: A. depolarized as potassium exits and calcium enters. B. depolarized as potassium enters and calcium exits. C. repolarized as sodium enters and calcium exits. D. hyperpolarized as sodium and calcium exit. E. hyperpolarized as potassium enters and calcium exits.

Back 6

A

Front 7

As with action potentials in other types of cells, the repolarization of cardiac muscle cells involves the: A. entrance of calcium through voltage-gated channels. B. exit of potassium through voltage-gated channels. C. entrance of sodium through voltage-gated channels. D. binding of Ach to Ach receptor. E. simultaneous closure of sodium channels and opening of calcium channels.

Back 7

B

Front 8

Most of the calcium that triggers contraction of cardiac muscle comes: A. into the cell through leakage channels in the sarcolemma. B. into the cell through voltage-gated channels in the sarcolemma. C. from the sarcoplasmic reticulum of the cell. D. from the Golgi apparatus of the cell.

Back 8

C

Front 9

To initiate a cardiac muscle cell contraction, calcium: A. binds to calmodulin. B. binds to troponin. C. binds to actin. D. binds to the Z-disc. E. binds to tropomyosin.

Back 9

B

Front 10

The time that starts when a muscle cell is depolarized and ends when it is able to be restimulated is the __________ period. ________________________________________

Back 10

refractory

Front 11

Like skeletal muscle cells, cardiac muscle cells have an absolute refractory period prior to repolarization. True False

Back 11

TRUE

Front 12

Which type of muscle cell exhibits a longer refractory period? A. Cardiac muscle cell B. Skeletal muscle cell

Back 12

A

Front 13

The plateau phase of an action potential: A. occurs only in skeletal muscle and makes those fibers' contractions most forceful. B. leads to tetanic contractions in smooth and skeletal muscle. C. allows cardiac muscle cells to contract and then relax without locking up. D. allows cardiac muscle cells to exhibit synchronous fibrilation.

Back 13

C

Front 14

What part of the cardiac conduction system is located in the posterior wall of the right atrium, adjacent to the entrance of the superior vena cava? A. AV bundle B. Bundle branches C. Purkinje fibers D. AV node E. SA node

Back 14

E

Front 15

The atrioventricular (AV) node is located in the: A. floor of the left atrium. B. floor of the right atrium. C. roof of the left ventricle. D. back wall of the right ventricle. E. back wall of the left ventricle.

Back 15

B

Front 16

In an ECG, what does the T wave denote? A. Depolarization of the atria B. Depolarization of the right ventricle C. Repolarization of the ventricles D. Closure of the AV valves E. Depolarization of the left ventricle

Back 16

C

Front 17

In an EKG, the P wave is generated when the: A. ventricles depolarize. B. atria depolarize. C. atria repolarize. D. ventricles repolarize. E. Purkinje fibers initiate an impulse.

Back 17

B

Front 18

Which segment of the ECG reflects the plateau phase of ventricular muscle cells' action potentials? A. P-T segment B. S-T segment C. Q-R segment D. P-R interval E. T-P interval

Back 18

B

Front 19

Someone with a heart block would have: A. a long P-R interval. B. a long T-P interval. C. a short P-R interval. D. a short T-P interval.

Back 19

A

Front 20

Someone with tachyarrhythmia would be expected to show an abnormally: A. small Q-T interval. B. large P-R interval. C. large R-R interval. D. high amplitude P wave.

Back 20

A

Front 21

During the S-T segment, what is occurring within cardiac muscle cells? A. Sodium is rapidly diffusing out of atrial muscle cells. B. Sodium channels are beginning to open in ventricular cells and calcium is entering through slow channels in atrial cells. C. Calcium is entering and potassium is leaving ventricular cells. D. Potassium is entering atrial cells and sodium is leaving ventricular cells.

Back 21

C

Front 22

During a cardiac cycle, how many of the four chambers contract at any one time? A. 1 B. 2 C. 4 D. Highly variable, depending on the heart beat rate E. None of these answers is correct

Back 22

B

Front 23

During ventricular systole: A. only the AV valves open. B. only the AV valves close. C. only the semilunar valves close. D. the semilunar valves close and the AV valves open. E. the semilunar valves open and the AV valves close.

Back 23

E

Front 24

The opening and closing of the heart valves is caused by: A. contraction and relaxation of papillary muscles that pull on heart strings. B. pressure changes of alternating contraction and relaxation during the cardiac cycle. C. contraction of the smooth muscle in the walls of the great vessels leaving the heart. D. action potentials within the cusps of the valves.

Back 24

B

Front 25

Blood moves into and then out of a heart chamber because: A. it moves along its pressure gradient, and that gradient depends on contraction and relaxation during the cardiac cycle. B. it is under constant pressure, but its movement is dictated by the control of valve openings and closures. C. the veins and arteries constrict and dilate to propel and attract blood. D. All of the choices are correct.

Back 25

A

Front 26

Atrial systole occurs just before: A. early ventricular diastole. B. late ventricular diastole. C. late ventricular systole. D. early ventricular systole.

Back 26

D

Front 27

The period of time when ventricles begin to contract is early ventricular _________. ________________________________________

Back 27

systole

Front 28

Just prior to atrial systole: A. all four chambers are at rest and AV valves are open. B. all four chambers are at rest and AV valves are closed. C. all four chambers are contracting and all valves are open. D. both ventricles are contracting and blood is being ejected into the major arteries. E. both atria are contracting and blood is being ejected into the major arteries.

Back 28

A

Front 29

Immediately prior to atrial systole, blood continues to enter the atria from the venae cavae and pulmonary veins. True False

Back 29

TRUE

Front 30

The shutting of the semilunar valves occurs during which phase? A. Early ventricular systole B. Late ventricular systole C. Early ventricular diastole D. Atrial systole E. Late ventricular diastole

Back 30

C

Front 31

Cardiac output is the amount of blood that is pumped: A. by a single ventricle in one hour. B. by a single ventricle in one minute. C. by both ventricles in one hour. D. by both ventricles in one minute. E. by the left ventricle into the aorta in one beat.

Back 31

B

Front 32

Cardiac output is usually expressed in: A. beats per minute. B. mL per beat. C. mm Hg. D. liters per minute.

Back 32

D

Front 33

Cardiac output equals the: A. end diastolic volume minus end systolic volume. B. blood pressure multiplied by heart rate. C. heart rate multiplied by stroke volume. D. stroke volume divided by heart rate. E. cardiac reserve minus the stroke volume.

Back 33

C

Front 34

Cardiac reserve is: A. the potential increase in stroke volume someone would show if they engaged in athletic training. B. the increase in cardiac output an individual is capable of demonstrating during vigorous exercise. C. the amount of blood left in the heart after the ventricle has contracted during cardiac cycles at rest. D. the blood that the heart uses to nourish its cardiac muscle and does not put into general circulation.

Back 34

B

Front 35

Cardiac reserve is greater in a nonathletic individual than in a highly trained athlete. True False

Back 35

FALSE

Front 36

A chemical that alters heart rate is known as a(n) __________ agent. ________________________________________

Back 36

chronotropic

Front 37

Large doses of certain stimulants can lead to dangerous increases in heart rates. Such a stimulant is a: A. positive chronotropic agent. B. negative chronotropic agent. C. positive inotropic agent. D. negative inotropic agent.

Back 37

A

Front 38

Norepinephrine is considered a positive chronotropic agent since it causes: A. less calcium to enter heart cells, which leads to lower risk of heart attack. B. more forceful contractions during each heart rate. C. an increase in the firing rate of SA node cells. D. thyroid hormone to have a steadying effect on heart activity. E. heart cell membrane potentials to become more positive during action potentials.

Back 38

C

Front 39

Which of the following is not one of the three main factors influencing stroke volume? A. Afterload B. Chronotropic agents C. Inotropic agents D. Venous return

Back 39

B

Front 40

According to the Frank-Starling law: A. the more calcium available to the heart cell, the more forceful it will contract. B. as the volume of blood entering the heart increases, ventricular contractions become more forceful. C. the faster the heart rate the larger the stroke volume. D. the greater the resistance from the arteries the higher the blood pressure.

Back 40

B

Front 41

The resistance in arteries to the ejection of blood by the heart is known as _________. ________________________________________

Back 41

afterload

Front 42

Preload is the stretch of the heart wall as determined by the amount of blood returned by the veins. True False

Back 42

TRUE

Front 43

A drug that decreased calcium levels in a muscle cell and thereby lowered the number of crossbridges formed during the heart's contractions would be a: A. positive chronotropic agent. B. negative chronotropic agent. C. positive inotropic agent. D. negative inotropic agent.

Back 43

D

Front 44

Which of the following would cause a decrease in cardiac output? A. An increase in venous return B. An increase in afterload C. Addition of positive inotropic agents D. An increase in heart rate

Back 44

B

Front 45

Explain the factors that affect cardiac output. In your answer provide one example of a positive inotropic agent and one example of a positive chronotropic agent. For each of those examples, explain what specifically happens to the cells of the heart when they have their effect.

Back 45

?

Front 46

Parasympathetic innervation of the heart occurs via: A. CN IV. B. CN VI. C. CN VIII. D. CN X. E. CN XII.

Back 46

D

Front 47

Sympathetic innervation of the heart arises from the ________ segments of the spinal cord. A. T1-T5 B. T3-T8 C. T5-T10 D. T6-T11 E. T11-L2

Back 47

A

Front 48

Parasympathetic innervation influences the heart rate, but generally tends to have no direct effect on the force of contractions. True False

Back 48

TRUE

Front 49

Sympathetic innervation of the heart: a: increases the heart rate b: decreases the heart rate c: increases the force of contractions d: decreases the force of contractions e: has no effect on contraction force A. a, c B. b, d C. a, d D. b, e E. a, e

Back 49

A

Front 50

The right border of the heart is supplied by the: A. circumflex artery. B. posterior interventricular artery. C. anterior interventricular artery. D. right marginal artery. E. great cardiac vein.

Back 50

D

Front 51

This artery is sometimes referred to as the "widowmaker" because blockage of it often leads to fatal heart attack. It serves the front of the heart and is more formally called the (2 words) _________ __________ artery. ________________________________________

Back 51

anterior interventricular or left anterior descending

Front 52

The left and right coronary arteries: A. are interconnected with several high volume anastomoses allowing for well perfused alternate blood paths. B. are functional end arteries since the blockage of one of them leads to tissue death in the area it supplies.

Back 52

B

Front 53

What would you expect a cardiologist to recommend if there was substantial occlusion to a patient's left coronary artery but not the right coronary artery? A. Since there are multiple alternate paths for blood delivery, the cardiologist would not intervene. B. Since this is a relatively small, unimportant artery, the cardiologist would not intervene. C. Since this is an important artery, and alternate vascular paths are inadequate, the cardiologist would treat the condition. D. Since occlusions require blood to be pumped at greater pressure, the cardiologist would prescribe drugs to raise blood pressure.

Back 53

C

Front 54

The posterior interventricular artery is a branch off of the: A. superior vena cava. B. left marginal artery. C. right coronary artery. D. left coronary artery. E. coronary sinus

Back 54

C