Ch 20 (Textbook Quiz)

Question 1

Internally, the right and left halves of the heart are separated by the

Answer 1

interatrial and interventricular septa

Question 2

most of the heart lies

Answer 2

to the left of midline of the thoracic cavity

Question 3

blood flows from the right atrium to the right ventricle through the __ valve

Answer 3

tricuspid

Question 4

the ridges formed by raised bundles of cardiac muscle fibers on the internal surface of the ventricles are called the

Answer 4

trabeculae carneae

Question 5

the outer layer of the heart, called the epicardium, is also the

Answer 5

visceral layer of the pericardium

Question 6

T or F: The interventricular septum separates the ventricles from the atria

Answer 6

false

Question 7

Why is the left ventricle wall thicker than the right?

Answer 7

L ventricle delivers blood to the systemic circulation

Question 8

tension in the chordae tendineae and papillary muscles during ventricular systole prevent

Answer 8

backflow of blood into the atria

Question 9

veins in the myocardium drain into the

Answer 9

coronary sinus

Question 10

the right atrium receives blood directly from 3 vessels. They are:

Answer 10

superior and inferior vena cava, and coronary sinus

Question 11

T or F: oxygenated blood is found in the R ventricle

Answer 11

False

Question 12

T or F: the right atrium receives blood from the coronary sinus

Answer 12

True

Question 13

T or F: Chordae tendineae stabilize the bicuspid valve and prevent it from prolapsing

Answer 13

true

Question 14

T or F: Blood enters the systemic circuit of blood flow by passing through the pulmonary valve

Answer 14

False

Question 15

T or F: In a mitral valve prolapse, a portion of the bicuspid valve protrudes into the left atrium

Answer 15

true

Question 16

T or F: The coronary artery carries blood to the right atrium

Answer 16

false

Question 17

what is the correct sequence of flow of an electrical impulse through the heart

Answer 17

SA node, AV node, AV bundle, Purkinje fibers

Question 18

The T wave on an EKG is due to

Answer 18

ventricular repolarization

Question 19

the sinoatrial node

Answer 19

contains autorhythmic fibers that repeatedly generate action potentials

Question 20

during repolarization of a cardiac muscle fiber

Answer 20

K+ moves out of the cell

Question 21

The AV bundle

Answer 21

is the only site where action potentials can conduct from the atria to the ventricles

Question 22

the plateau phase of the action potential in cardiac muscle is due to

Answer 22

inflow of Ca2+

Question 23

ventricular systole is caused by

Answer 23

ventricular depolarization

Question 24

which of the following occurs during that portion of the EKG designated as the P wave

Answer 24

atrial myocardium depolarizes

Question 25

T or F: Gap junctions in the intercalated disks allow action potentials to pass from one cardiac muscle cell to another

Answer 25

True

Question 26

T or F: Purkinje fibers transmit the action potential from the apex of the heart to the ventricles

Answer 26

true

Question 27

T or F: Cardiac muscle fibers produce much of their energy by way of anaerobic respiration

Answer 27

False

Question 28

the closing of the semilunar valves

Answer 28

produces the second heart sound

Question 29

when the ventricles relax

Answer 29

ventricular pressure drops

Question 30

the left ventricle refills with blood in preparation for initiation of the next cardiac cycle during ventricular

Answer 30

diastole

Question 31

the first heart sound is associated with

Answer 31

both atrioventricular valves closing during ventricular systole

Question 32

the plateau phase of the depolarization of muscle fibers in the ventricles of the heart extends from

Answer 32

the QRS to the T wave of the ECG

Question 33

T of F: blood pressure is highest in the aorta during ventricular diastole

Answer 33

false

Question 34

nervous regulation of the heart originates in the

Answer 34

medulla oblangata

Question 35

release of norepinephrine from nerve fibers causes

Answer 35

increased heart rate and force of contraction

Question 36

nerve impulses that reach the heart by means of the vagus nerve are

Answer 36

parasympathetic and cause decreased heart rate

Question 37

what is the cardiac output of a patient with a stroke volume of 70mL/ventricular contraction whose heart rate is 90 beats/minute

Answer 37

6300 mL/minute

Question 38

positive inotropic agents

Answer 38

increase contractility of the heart

Question 39

the Frank-Starling law of the heart states that

Answer 39

the volume of blood that enters the heart during diastole directly affects the force of contraction at systole

Question 40

when the left ventricle fails, blood backs up in the lungs, causing

Answer 40

pulmonary edema

Question 41

T or F: Cardiac output is the volume of blood ejected from the left ventricle into the aorta each minute

Answer 41

true

Question 42

T or F: Baroreceptors monitor changes in blood chemistry

Answer 42

false

Question 43

during exercise, increased muscle contraction helps return more blood to the heart. This would lead to

Answer 43

increased stroke volume

Question 44

what is a benefit of regular aerobic training

Answer 44

increased maximal cardiac output during strenuous exercise

Question 45

Embryologically, the heart is a derivative of the

Answer 45

mesoderm

Question 46

T or F: During fetal development, an opening called the foramen ovale allows blood in the right and left ventricles to mix

Answer 46

false

Question 47

asynchronous, haphazard, ventricular contractions are characteristic of

Answer 47

ventricular fibrillation