Chapter 20 Heart 3rd version

Depolarization of the atria corresponds to the EKG's

P wave

Which of the following would be greater? A) the end-diastolic volume when the heart rate is 150 beats/minute B) the end-diastolic volume when the heart rate is 60 beats/minute

B) the end-diastolic volume when the heart rate is 60 beats/minute

________ is to slow heart rate as ________ is to fast heart rate.

Bradycardia; tachycardia

The right ventricle pumps blood to the

right and left lungs

coronary veins empty into the

right atrium

The ________ deliver(s) blood to the myocardium.

right coronary artery and left coronary artery

The pulmonary semilunar valve prevents backward flow into the

right ventricle

The T wave on an ECG tracing represents

ventricular contraction

in cardiac muscle

at least half of the calcium ion required for contraction comes from outside the cell.

The cusps (leaflets) of atrioventricular valves attach directly to

chordae tendineae

The function of the atrium is to

collect blood and pump blood to the ventricle

As blood leaves the right ventricle it passes through the ________ and then into the pulmonary trunk.

conus arteriosus

The great and middle cardiac veins drain blood into the

coronary sinus

Artery is to ________ as vein is to ________.

efferent;afferent

The pulmonary veins carry blood to the

heart

The atrioventricular valves permit blood flow

in one direction only

In cardiac muscle, the fast depolarization phase of the action potential is the result of

increased membrane permeability to sodium ions.

Each of the following factors will increase cardiac output, except

increased parasympathetic stimulation.

The first heart sound ("lub")

is associated with closing of the mitral valve

The ________ ventricle has a greater workload than the ________.

left;right ventricle

The pulmonary arteries carry blood to the

lungs

Rupture of the papillary muscles in the left ventricle may result in

mitral regurgitation. mitral valve prolapse. bicuspid regurgitation. bicuspid prolapse.

Cardiac output is increased by

more sympathetic stimulation. increased stroke volume.

When the semilunar valves close, the AV valves then

open

Acetylcholine slows the heart because it

opens potassium ion channels in SA node cells. causes the pacemaker potential to depolarize more quickly.

Contractions of the papillary muscles

prevent the atrioventricular valves from reversing into the atria.

Blood leaves the right ventricle by passing through the

pulmonary valve

When a blood clot forms on a ruptured plaque in a coronary artery, the condition is referred to as a(n)

coronary thrombosis

The visceral pericardium is the same as the

epicardium

Which of the following would increase heart rate?

increased sympathetic stimulation of SA node decreased parasympathetic stimulation of nodal fibers increased levels of epinephrine faster depolarization of the pacemaker potential

The foramen ovale in the fetal heart is located in the

intertribal septum

Intercalated discs serve to transfer ________ from cell to cell.

ionic current, action potentials, the force of contraction

Blood is supplied to the left atrium by the

left coronary artery

The circumflex branch and the anterior interventricular artery are branches of the

left coronary artery

The coronary sulcus is a groove that

marks the border between the atria and ventricles.

If the connection between the vagus nerve and the heart is cut, which of these changes will occur? A)heart will beat slower B)stroke volume will decrease C)cardiac output will decrease D)nodal fibers will depolarize more slowly

none of the above

Excess fluid in the ________ causes cardiac tamponade

pericardial cavity

Compared to the right ventricle, the left ventricle has all the following characteristics, except that it

pumps a greater volume

During the T wave of the electrocardiogram, the ventricles are

repolarizing, relaxing

During ventricular systole, the

AV valves are closed.

The first heart sound is heard when the

AV valves close

The structure that permits blood flow from the right atrium to the left atrium in the fetal circulation is the

Foramen ovale

The long plateau phase of the cardiac muscle action potential is due to

calcium channels remaining open.

Most of the middle layer in the heart wall is composed of

cardiac myocytes

The term used to describe fluid collecting in the pericardial cavity that restricts the movement of the heart is known as

cardiac tamponade

The right atrium receives blood from the

coronary, superior vena cava and inferior vena cava

Drugs that block the beta-one adrenergic receptors will

decrease heart rate

An increase in the rate of action potentials from baroreceptors will reflexly lead to

decrease in heart rate. decrease in blood pressure.

Drugs known as calcium channel blockers such as nifedipine can be used to

decrease the force of cardiac contraction. decrease blood pressure. dilate the coronary arteries. produce a negative inotropic effect.

When the left ventricle contracts, the diameter of the ventricular chamber

decreases

When the left ventricle contracts, the distance from the apex to the base

decreases

Cardiac output can be increased by all of the following except one. Choose the exception

decreasing ejection fraction

The P wave of the electrocardiogram is a signal from

depolarization of the atria.

Stroke volume depends on

end diastolic volume. the contractility of the ventricle. the pressure required to pump blood into the aorta.

The interventricular sulci and coronary sulcus contain

fat, arteries, veins

Heart rate is controlled by neurons of the cardiovascular center located in the

medulla oblongata

Pacemaker cells in the SA node

show a slow spontaneous depolarization. are connected by gap junctions to atrial myocytes.

A heartbeat lasts

370 msec.

At a heart rate of 60 beats/minute, a cardiac cycle lasts

1 sec

________ is to contraction as ________ is to relaxation

Systole;diastole ejection;filling

The heart beats approximately ________ times each day.

100,000

there are ______ pulmonary veins

4

The following are structural components of the conducting system of the heart. 1. Purkinje fibers 2. AV bundle 3. AV node 4. SA node 5. bundle branches The sequence in which excitation would move through this system is

4, 3, 2, 5, 1.

The following is a list of vessels and structures that are associated with the heart. 1. right atrium 2. left atrium 3. right ventricle 4. left ventricle 5. venae cavae 6. aorta 7. pulmonary trunk 8. pulmonary veins

5, 1, 3, 7, 8, 2, 4, 6

The heart pumps approximately ________ liters of blood each day

8,000

Pacemaker cells isolated from the SA node generate action potentials at ________ beats per minute.

80-100

The earlike extension of the atrium is the

Auricle

Cardiac muscle cells and skeletal muscle cells differ in a few ways. Which of the following is not one of them?

Cardiac muscle cells lack transverse tubules

The first blood vessels to branch from the aorta are the ________ arteries

Coronary

Abnormally slow depolarization of the ventricles would most change the shape of the ________ in an ECG tracing.

QRS complex

Depolarization of the ventricles is represented on an electrocardiogram by the

QRS complex

During the cardiac cycle, the

QRS complex of the ECG precedes the increase in ventricular pressure. First heart sound coincides with the QRS complex of the ECG

Blood returning to the heart from the systemic circuit first enters the

Right Atrium

The marginal branch and posterior interventricular branch are branches of the

Right Coronary artery

"An increase in end-diastolic volume increases the stroke volume" is a way of stating

Starling's law of the heart.

The heart is roughly the size of

a man's clenched fist

The connective tissue fibers of the myocardium

add strength and prevent overexpansion of the heart. help distribute the forces of contraction. provide elasticity to help return the heart to its normal size. provide physical support for cardiac muscle.

The left ventricle pumps blood to the

aorta

A heart murmur might be caused by

aortic valve stenosis. or mitral valve insufficiency. or pulmonic valve insufficiency.

Which of the following descriptions matches the term near the left fifth intercostal space?

apex of the heart

During the isovolumetric phase of ventricular systole, the

atrioventricular valves and semilunar valves are closed.

Activation of which kind of receptor causes heart rate to increase?

beta-one-receptor

The bicuspid or mitral valve is located

between the left atrium and left ventricle

The ________ valve prevents backward flow into the left atrium.

bicuspid

The heart is innervated by ________ nerves

both parasympathetic and sympathetic

Which of these comparisons between skeletal and heart muscle is false?

both rely entirely on oxidative metabolism for energy.

The normal pacemaker of the heart is located in the

sinoatrial node

Analysis of the electrocardiogram can reveal all of the following, except the

stroke volume

The volume of blood ejected from each ventricle during a contraction is called the

stroke volume

Cardiac cells damaged by infarction will show which of the following?

switch to anaerobic metabolism. release of enzymes into the circulation. release of troponin T and I into the circulation. release of MB-CK into the circulation

The phase in the cardiac cycle when the mitral valve is closed and the aortic valve is open is the

systolic ejection phase

As a result of the long refractory period in the cardiac action potential, cardiac muscle cannot exhibit

tetany

Blood is supplied to the myocardium by

the coronary arteries.

The wall of the left ventricle is thicker than the right because

the left ventricle does more work than the right ventricle. the left ventricle produces a higher pressure than the right.

Which of the following is greater during left ventricular systole?

the peak pressure in the ventricle

Tetanic muscle contractions don't occur in a normal cardiac muscle because

the refractory period lasts until the muscle relaxes.

Blood flowing into the heart from the venae cavae flows next through the ________ valve.

tricuspid

Blood returning to the heart from the pulmonary circuit first enters the

Left Atrium

In the middle of the thoracic cavity is a region occupied by the heart, great vessels, thymus, esophagus, and trachea called the

Mediastinum

AV nodal cells are poorly interconnected compared to contractile cells but they have bigger diameters.

The first part of the statement is true but the second part is false