Chapter 18: The Cardiovascular System: The Heart Part A

aortic semilunar valve

prevents backflow of blood into the left ventricle right answer feedback

pulmonary semilunar valve

prevents backflow of blood into the right ventricle

systole

Contraction of the heart

What of the following is NOT a role of the fibrous pericardium?

It facilitates heart contraction.

Role of fibrous pericardium

It prevents the heart from overfilling with blood. It anchors the heart to surrounding structures. It protects the heart.

In the fetus, blood from the left and right sides of the heart normally mix.

True

Which of the following is a difference between cardiac muscle and skeletal muscle?

Unlike skeletal muscle cells, cardiac muscle cells can be autorhythmic.

The superior chambers of the heart are called the __________.

atria

The P wave of an electrocardiogram represents __________.

atrial depolarization

The second heart sound (the "dup" of "lub-dup") is caused by the __________.

closure of the semilunar valves

The lining of the heart chambers is called the __________.

endocardium

Into which chamber of the heart do the pulmonary veins deliver blood?

left atrium

Freshly oxygenated blood is delivered to the __________, and then it passes into the __________ to be pumped to the body tissues (systemic circuit).

left atrium; left ventricle

The most muscular chamber of the heart is the __________.

left ventricle

Which of the following would lead to a decrease in heart rate?

parasympathetic stimulation

posterior interventricular artery

runs to the apex of the heart

The role of the atrioventricular node (AV node) is to __________.

slow down impulses so that the atria can contract to fill the adjacent ventricles with blood

anterior interventricular artery

supplies blood to the interventricular septum and anterior walls of both ventricles

right marginal artery

supplies blood to the lateral right side of the myocardium

circumflex artery

supplies blood to the left atrium and posterior walls of the left ventricle

cardiac output

the amount of blood pumped by each ventricle in one minute

cardiac cycle

the events associated with blood flow through the heart during one complete heartbeat

stroke volume

the volume of blood pumped by one ventricle with each heartbeat

mitral (bicuspid) valve

valve between the left atrium and the left ventricle.

tricuspid valve

valve between the right atrium and the right ventricle