Deck 17: The Cardiovascular System: the Heart

Question 1

Hemorrhage with a large loss of blood causes _.

A)no change in blood pressure but a change in respiration
B)a lowering of blood pressure due to change in cardiac output
C)a rise in blood pressure due to change in cardiac output
D)no change in blood pressure but a slower heart rate

Answer 1

B

Question 2

If the vagal nerves to the heart were cut,the result would be that .

A)the heart rate would increase by about 25 beats per minute
B)parasympathetic stimulation would increase,causing a decrease in heart rate
C)the AV node would become the pacemaker of the heart
D)the heart would stop,since the vagal nerves trigger the heart to contract

Answer 2

A

Question 3

The time of day most hazardous for heart attacks is _ .

A)morning
B)noontime
C)evening
D)during sleep

Answer 3

A

Question 4

The fact that the left ventricle of the heart is thicker than the right ventricle reveals that it .

A)pumps a greater volume of blood
B)sends blood through a smaller valve
C)pumps blood against a greater resistance
D)expands the thoracic cage

Question 5

Norepinephrine acts on the heart by .

A)causing threshold to be reached more quickly
B)blocking the action of calcium
C)decreasing heart contractility
D)causing a decrease in stroke volume

Question 6

During the period of ventricular filling .

A)pressure in the heart is at its peak
B)it is represented by the P wave on the ECG
C)blood flows passively through the atria and the open AV valves into the ventricles
D)the atria remain in diastole

Question 7

If cardiac muscle is deprived of its normal blood supply,damage would primarily result from .

A)a decrease in the number of available mitochondria for energy production
B)decreased delivery of oxygen
C)a lack of nutrients to feed into metabolic pathways
D)an inadequate supply of lactic acid

Question 8

Select the correct statement about the structure of the heart wall.

A)The heart chambers are lined by the endomysium.
B)The fibrous skeleton forms the bulk of the heart.
C)The myocardium is the layer of the heart that actually contracts.
D)Connective tissue in the heart wall aids in the conduction of the action potential.

Question 9

When viewing a dissected heart,it is easy to visually discern the right and left ventricles by .

A)tracing out where the auricles connect
B)finding the papillary muscles
C)locating the apex
D)noticing the thickness of the ventricle walls

Question 10

During contraction of heart muscle cells .

A)some calcium enters the cell from the extracellular space and triggers the release of larger amounts of calcium from intracellular stores
B)calcium is prevented from entering cardiac fibers that have been stimulated
C)the action potential is prevented from spreading from cell to cell by gap junctions
D)the action potential is initiated by voltage- gated slow calcium channels

Question 11

If the length of the absolute refractory period in cardiac muscle cells was the same as it is for skeletal muscle cells _ .

A)it would be much longer before cardiac cells could respond to a second stimulation
B)tetanic contractions might occur,which would stop the heart's pumping action
C)contractions would last as long as the refractory period
D)it would be less than 1-2 ms

Question 12

Which of the following is not an age- related change affecting the heart?

A)fibrosis of cardiac muscle
B)decline in cardiac reserve
C)atherosclerosis
D)thinning of the valve flaps

Question 13

Small muscle masses attached to the chordae tendineae are the .

A)trabeculae carneae
B)venae cavae
C)papillary muscles
D)pectinate muscles

Question 14

Select the correct statement about the function of myocardial cells.

A)Each cardiac muscle cell is innervated by a sympathetic nerve ending so that the nervous system can increase heart rate.
B)The refractory period in skeletal muscle is much longer than that in cardiac muscle.
C)The entire heart contracts as a unit or it does not contract at all.
D)The influx of potassium ions from extracellular sources is the initiating event in cardiac muscle contraction.

Question 15

Which of the following is not part of the conduction system of the heart?

A)AV node
B)AV valve
C)bundle of His
D)SA node

Question 16

Which of these vessels receives blood during ventricular systole?

A)pulmonary arteries only
B)both the aorta and pulmonary trunk
C)pulmonary veins only
D)aorta only

Question 17

Normal heart sounds are caused by which of the following events?

A)opening and closing of the heart valves
B)excitation of the SA node
C)closure of the heart valves
D)friction of blood against the chamber walls

Question 18

Select the correct statement about the heart valves.

A)Aortic and pulmonary valves control the flow of blood into the heart.
B)The AV valves are supported by chordae tendineae so that regurgitation of blood into the atria during ventricular contraction does not occur.
C)The mitral valve separates the right atrium from the right ventricle.
D)The tricuspid valve divides the left atrium from the left ventricle.

Question 19

The tricuspid valve is closed .

A)while the ventricle is in diastole
B)while the atrium is contracting
C)by the movement of blood from atrium to ventricle
D)when the ventricle is in systole

Question 20

If we were able to artificially alter the membrane permeability of pacemaker cells so that sodium influx is more rapid,.

A)heart rate would decrease,but blood pressure would rise due to the excess sodium present
B)potassium channels compensate and no change in heart rate would occur
C)tetanic contraction would occur due to the short absolute refractory period of cardiac muscle
D)threshold is reached more quickly and heart rate would increase

Question 21

The second heart sound is heard during which phase of the cardiac cycle?

A)ventricular ejection
B)isovolumetric relaxation
C)ventricular filling
D)isovolumetric contraction

Question 22

What is bradycardia?

Question 23

The and valves of the heart have no chordae tendineae attached.

Question 24

Which of the events below does not occur when the semilunar valves are open?

A)AV valves are closed.
B)Ventricles are in systole.
C)Ventricles are in diastole.
D)Blood enters pulmonary arteries and the aorta.

Question 25

Isovolumetric contraction _.

A)occurs immediately after the aortic and pulmonary valves close
B)occurs only in people with heart valve defects
C)occurs while the AV valves are open
D)refers to the short period during ventricular systole when the ventricles are completely closed chambers

Question 26

Compared to skeletal muscle,cardiac muscle .

A)lacks striations
B)has gap junctions that allow it to act as a functional syncytium
C)cells are larger than skeletal muscle cells
D)has more nuclei per cell

Question 27

The membrane covers the heart.

Question 28

Define the terms end diastolic volume EDV)and end systolic volume ESV)and relate them to the calculation of stroke volume.

Question 29

The enlarged coronary vessel outside the heart that empties blood into the right atrium is the .

Question 30

The term for pain associated with deficient blood delivery to the heart that may be caused by the transient spasm of coronary arteries is .

A)angina pectoris
B)pericarditis
C)myocardial infarct
D)ischemia

Question 31

The P wave of a normal electrocardiogram indicates .

A)atrial depolarization
B)atrial repolarization
C)ventricular repolarization
D)ventricular depolarization

Question 32

The heart is called a "double pump" because there are two functionally separate circulations.Trace the pathway of each of these circulations and include the following information: heart chambers involved,major blood vessels involved,and general areas through which the blood flows.Begin with the right atrium.

Question 33

The valve of the heart has three valves with chordae tendineae.

Question 34

What two important functions does the cardiac conduction system perform?

Question 35

Explain autorhythmicity in cardiac muscle cells.

Question 36

Which of the following factors does not influence heart rate?

A)skin color
B)body temperature
C)gender
D)age

Question 37

Which vessel of the heart receives blood during right ventricular systole?

A)aorta
B)pulmonary veins
C)venae cavae
D)pulmonary trunk

Question 38

The left ventricular wall of the heart is thicker than the right wall in order to .

A)accommodate a greater volume of blood
B)pump blood through a smaller valve
C)expand the thoracic cage during diastole
D)pump blood with greater pressure

Question 39

Select the correct statement about cardiac output.

A)Stroke volume increases if end diastolic volume decreases.
B)If a semilunar valve were partially obstructed,the end systolic volume in the affected ventricle would be decreased.
C)A slow heart rate increases end diastolic volume,stroke volume,and force of contraction.
D)Decreased venous return will result in increased end diastolic volume.

Question 40

Why is oxygen so much more critical to the heart muscle than to skeletal muscles?

Question 41

CO =___________ × SV.

Question 42

What is the functional importance of the intercalated discs of cardiac muscle? What is the functional importance of the fibrous skeleton of the heart?

Question 43

Define systole and diastole.Which heart chambers are usually referenced when these terms are used?

Question 44

What is the difference between the auricles and the atria?

Question 45

The ECG T wave interval represents .