blood

Question 1

A foramen ovale ________.
-is a connection between the pulmonary trunk and the aorta in the fetus
-connects the two atria in the fetal heart
-is a shallow depression in the interventricular septum
-is a condition in which the heart valves do not completely close

Answer 1

connects the two atria in the fetal heart

Question 2

Blood within the pulmonary veins returns to the ________.
left atrium
left ventricle
right atrium
right ventricle

Answer 2

left atrium

Question 3

Commotio cordis is heart failure due to a ________.
-severe electrical shock to the body
-loss of blood from an artery
-mild electrical shock to the heart itself
-relatively mild blow to the chest that occurs during a vulnerable interval (2 ms) when the heart is repolarizing

Answer 3

relatively mild blow to the chest that occurs during a vulnerable interval (2 ms) when the heart is repolarizing

Question 4

Compared to skeletal muscle, cardiac muscle ________.
-has gap junctions that allow it to act as a functional syncytium
-has more nuclei per cell
-cells are larger than skeletal muscle cells
-lack striations

Answer 4

has gap junctions that allow it to act as a functional syncytium

Question 5

Damage to the ________ is referred to as heart block.
AV bundle
AV valves
AV node
SA node

Answer 5

AV node

Question 6

During contraction of heart muscle cells ________.
-calcium is prevented from entering cardiac fibers that have been stimulated
-the action potential is initiated by voltage-gated slow calcium channels
-some calcium enters the cell from the extracellular space and triggers the release of larger amounts of calcium from intracellular stores
-the action potential is prevented from spreading from cell to cell by gap junctions

Answer 6

some calcium enters the cell from the extracellular space and triggers the release of larger amounts of calcium from intracellular stores

Question 7

During the period of ventricular filling ________.
-it is represented by the P wave on the ECG
-the atria remain in diastole
-blood flows mostly passively through the atria and the open AV valves into the ventricles
-pressure in the heart is at its peak

Answer 7

blood flows mostly passively through the atria and the open AV valves into the ventricles

Question 8

Hemorrhage with a large loss of blood causes ________.
-no change in blood pressure but a slower heart rate
-a rise in blood pressure due to change in cardiac output
-no change in blood pressure but a change in respiration
-a lowering of blood pressure due to change in cardiac output

Answer 8

a lowering of blood pressure due to change in cardiac output

Question 9

If cardiac muscle is deprived of its normal blood supply, damage would primarily result from ________.
-an inadequate supply of lactic acid
-a decrease in the number of available mitochondria for energy production
-a lack of nutrients to feed into metabolic pathways
-decreased delivery of oxygen

Answer 9

decreased delivery of oxygen

Question 10

If the length of the absolute refractory period in cardiac muscle cells was the same as it is for skeletal muscle cells, ________.
-it would be less than 1—2 m
-contractions would last as long as the refractory period
-tetanic contractions might occur, which would stop the heart’s pumping action
-it would be much longer before cardiac cells could respond to a second stimulation

Answer 10

tetanic contractions might occur, which would stop the heart’s pumping action

Question 11

If the vagal nerves to the heart were cut, the result would be that ________.
-the heart would stop, since the vagal nerves trigger the heart to contract
-parasympathetic stimulation would increase, causing a decrease in heart rate
-the AV node would become the pacemaker of the heart
-the heart rate would increase by about 25 beats per minute

Answer 11

the heart rate would increase by about 25 beats per minute

Question 12

If we were able to artificially alter the membrane permeability of pacemaker cells so that sodium influx is more rapid, ________.
-tetanic contraction would occur due to the short absolute refractory period of cardiac muscle
-heart rate would decrease, but blood pressure would rise due to the excess sodium present
-potassium channels compensate and no change in heart rate would occur
-threshold is reached more quickly and heart rate would increase

Answer 12

threshold is reached more quickly and heart rate would increase

Question 13

Isovolumetric contraction ________.
-refers to the short period during ventricular systole when the ventricles are completely closed chambers
-occurs immediately after the aortic and pulmonary valves close
-occurs only in people with heart valve defects
-occurs while the AV valves are open

Answer 13

refers to the short period during ventricular systole when the ventricles are completely closed chambers

Question 14

Norepinephrine acts on the heart by ________.
-decreasing heart contractility
-blocking the action of calcium
-causing threshold to be reached more quickly
-causing a decrease in stroke volume

Answer 14

causing threshold to be reached more quickly

Question 15

Normal heart sounds are caused by which of the following events?
-closure of the heart valves
-friction of blood against the chamber walls
-opening and closing of the heart valves
-excitation of the SA node

Answer 15

closure of the heart valves

Question 16

Select the correct statement about cardiac output.
-A slow heart rate increases end diastolic volume, stroke volume, and force of contraction.
-If a semilunar valve were partially obstructed, the end systolic volume in the affected ventricle would be decreased.
-Stroke volume increases if end diastolic volume decreases.
-Decreased venous return will result in increased end diastolic volume.

Answer 16

A slow heart rate increases end diastolic volume, stroke volume, and force of contraction.

Question 17

Select the correct statement about the function of myocardial cells.
-Cardiac muscle cells are innervated by sympathetic, parasympathetic, and somatic nerve fibers so that the nervous system can increase heart rate.
-The refractory period in skeletal muscle is much longer than that in cardiac muscle.
-The entire heart contracts as a unit or it does not contract at all.
-The influx of potassium ions from extracellular sources is the initiating event in cardiac muscle contraction.

Answer 17

The entire heart contracts as a unit or it does not contract at all.

Question 18

Select the correct statement about the heart valves.
-The mitral valve separates the right atrium from the right ventricle.
-The tricuspid valve divides the left atrium from the left ventricle.
-The AV valves are supported by chordae tendineae so that regurgitation of blood into the atria during ventricular contraction does not occur.
-Aortic and pulmonary valves control the flow of blood into the heart.

Answer 18

The AV valves are supported by chordae tendineae so that regurgitation of blood into the atria during ventricular contraction does not occur.

Question 19

Select the correct statement about the structure of the heart wall.
-The myocardium is the layer of the heart that actually contracts.
-The fibrous skeleton forms the bulk of the heart.
-Connective tissue in the heart wall aids in the conduction of the action potential.
-The heart chambers are lined by the endomysium

Answer 19

The myocardium is the layer of the heart that actually contracts.

Question 20

The P wave of a normal electrocardiogram indicates ________.
ventricular depolarization
ventricular repolarization
atrial depolarization
atrial repolarization

Answer 20

atrial depolarization

Question 21

The condition where fluid compresses the heart and limits its ability to contract is called ________.
angina pectoris
cardiac tamponade
pericarditis
myocardial infarction

Answer 21

cardiac tamponade

Question 22

The fact that the left ventricle of the heart is thicker than the right ventricle reveals that it ________.
-sends blood through a smaller valve
-pumps a greater volume of blood
-pumps blood against a greater resistance
-expands the thoracic cage

Answer 22

pumps blood against a greater resistance

Question 23

The left ventricular wall of the heart is thicker than the right wall in order to ________.
-accommodate a greater volume of blood
-pump blood with greater pressure
-pump blood through a smaller valve
-expand the thoracic cage during diastole

Answer 23

pump blood with greater pressure

Question 24

The second heart sound is heard during which phase of the cardiac cycle?
ventricular ejection
ventricular filling
isovolumetric relaxation
isovolumetric contraction

Answer 24

isovolumetric relaxation

Question 25

The source of blood carried to capillaries in the myocardium would be the ________.
coronary veins
coronary arteries
fossa ovalis
coronary sinus

Answer 25

coronary arteries

Question 26

The term for pain associated with deficient blood delivery to the heart that may be caused by the transient spasm of coronary arteries is ________.
pericarditis
ischemia
angina pectoris
myocardial infarct

Answer 26

angina pectoris

Question 27

The tricuspid valve is closed ________.
-when the ventricle is in systole
-while the ventricle is in diastole
-by the movement of blood from atrium to ventricle
-while the atrium is contracting

Answer 27

when the ventricle is in systole

Question 28

To auscultate the aortic semilunar valve, you would place your stethoscope in the ________.
-fifth right intercostal space
-fifth intercostal space inferior to the left nipple
-second intercostal space to the right of the sternum
-second intercostal space to the left of the sternum

Answer 28

second intercostal space to the right of the sternum

Question 29

When viewing a dissected heart, it is easy to visually discern the right and left ventricles by ________.
-locating the apex
-noticing the thickness of the ventricle walls
-finding the papillary muscles
-tracing out where the auricles connect

Answer 29

noticing the thickness of the ventricle walls

Question 30

Which of the events below does not occur when the semilunar valves are open?
-Ventricles are in diastole.
-Ventricles are in systole.
-AV valves are closed.
-Blood enters pulmonary arteries and the aorta.

Answer 30

Ventricles are in diastole.

Question 31

Which of the following factors does not influence heart rate?
body temperature
skin color
gender
age

Answer 31

skin color

Question 32

Which of the following is not an age-related change affecting the heart?
-decline in cardiac reserve
-thinning of the valve flaps
-atherosclerosis
-fibrosis of cardiac muscle

Answer 32

thinning of the valve flaps

Question 33

Which of the following is not part of the conduction system of the heart?
SA node
AV valve
AV node
bundle of His

Answer 33

AV valve

Question 34

Which of these vessels receives blood during ventricular systole?
-both the aorta and pulmonary trunk
-pulmonary veins only
-pulmonary arteries only
-aorta only

Answer 34

both the aorta and pulmonary trunk

Question 35

Which vessel(s) of the heart receive(s) blood during right ventricular systole?
pulmonary veins
pulmonary trunk
venae cavae
aorta

Answer 35

pulmonary trunk