ch 21

The heart wall is composed of ________ layers of tissues.

3

Which of the following is true of the coronary arteries?

They originate at the base of the aorta and are the first branches off this vessel.

In terms of time, at rest one cardiac cycle lasts

a little under 1 second.

The broad, superior portion of the heart is the

base

Which of the following is a major component of the conduction system located in the interventricular septum?

bundle branches

Blood is supplied to the muscle of the heart through the

coronary arteries

The reinforcing layer of the pericardium is the ________ layer.

firbrous

The right ventricle

has thinner muscular walls than does the left ventricle

Cardiac muscle differs from other muscle tissue in

having fibers connected to one another at intercalated discs.

Blood travels from the left atrium to the left ventricle through the

mitral valve

Papillary muscles of the right ventricle receive a signal to contract from (the)

moderator band.

Cardiac muscle cells do not need ________ to contract.

nervous stimulation

The serous membrane lining the pericardial cavity is the

pericardium

During most of ventricular diastole, the

the ventricles are filling

The chambers of the heart empty during

ventricular systole

The contraction of any one cardiac muscle fiber

will cause the contraction of several others.

Which of the following is an incorrect association?

atrioventricular- aortic valve

The main pacemaker region of the heart is

in the wall of the right atrium

Valves of the heart open and close due to

pressure changes

The coronary artery found under the right atrium is (the)

right coronary artery.

Blood that is transported to and from all of the tissues of the body with the exception of the lungs is in the

system circuit

The heart has the unique ability to change its workload. On average the heart can pump between ________ and ________ liters of blood per minute.

5;30

Pacemaker cells of the SA node depolarize about

80-100 times per minute

Which of the following conditions would cause the amount of blood entering the ascending aorta with each contraction of the heart to increase?

The amount of blood entering the right atrium of the heart was increased.

How would the heart rate be affected if there were a blockage of the AV node?

The electrical stimuli from the SA node would be normal, but the rate of contraction would slow or be irregular.

Cardiac muscle cells obtain energy almost exclusively through

aerobic respiration

Which of the following empty directly into the right atrium?

anterior cardiac veins

Grooves on the external surface of the heart that divide the right and left ventricles include the

anterior interventricular sulcus.

The left ventricle pumps blood into the

aorta

Blood vessels traveling away from the heart are

arteries

Which of the following is true of the contraction of the heart?

cardiac contractions are coordinated by specialized conductive cardiac muscle fibers

The superior end of the right ventricle near the pulmonary valve is called (the)

conus arteriosus

When a clot forms in a coronary vessel and obstructs blood flow to the muscle, the condition is referred to as a(n)

coronary thrombosis.

At rest the heart rate is usually ________ by parasympathetic control.

decreased

During their period of systole, the inner volume of the atrial chambers

decreases

Externally the posterior and inferior portions of the left ventricle form the

diaphragmatic surface.

During one cardiac cycle the ventricles spend most of their time in

diastole

The innermost layer of the heart wall is the

endocardium

The visceral pericardium is also called the

epicardium

The wall between the atria is called the

interatrial septum

Structures in the heart that carry electrical signals from the SA node to the AV node are called

internodal pathways.

The thick muscular partition that separates the two ventricles entire heart is the

interventricular septum

One of the major differences between skeletal muscle and cardiac muscle is that cardiac muscle

lacks triads.

Which of the following is supplied with blood by the left anterior descending artery?

left ventricle

Prominent muscular ridges that run along the inner surface of the auricle and across the adjacent atrial wall are the

pectinate muscles.

The tough structure that surrounds the heart and helps reinforce and maintain position of the heart is the

pericardial sac.

The connective tissues of the heart

provide a strong fibrous cross-linkage system wrapping adjacent muscle cells together

The right ventricle is associated exclusively with which of the following?

pulmonary trunk

The left atrium receives blood from the

pulmonary veins.

The moderator band is located in the

right ventricle

The fibrous skeleton of the heart is located

surrounding the heart valves

The phase of the cardiac cycle during which each chamber contracts and pushes blood into the next structure is

systole

The ability of the blood to supply oxygen and remove carbon dioxide from the tissues depends upon

the ability of the blood to remain in constant motion.

Nodal activity of the heart may be influenced or modified by

the autonomic nervous system

The most serious place for a blockage of a coronary artery is

the left coronary artery

If a small blood clot passes through the heart and heart vessels, where is it most likely to cause damage if it becomes immobilized?

the left coronary artery.

Which of the chambers of the heart can generate the greatest pressure?

the left ventricle