Cells in the heart’s sinoatrial node function as the heart’s pacemaker thanks to their ability to generate _______.

Blood is composed of formed elements, which are cells and cell fragments, and plasma, which is the _______ portion of blood.

There are three kinds of formed elements: _______, _______, and _______. Plasma, meanwhile, is overwhelmingly composed of _______.

Arteries carry blood _______ the heart, while veins carry blood _______ the heart. The tiny blood vessels called_______ connect arteries to veins.

Heart attacks have sometimes been called a disease of modern civilization because their incidence is much higher in affluent, more-developed societies than in poorer, less-developed ones. Why should this be so?

The formed elements of blood include (select all that apply):

a. plasma.

b. white blood cells.

c. fibrinogen.

d. red blood cells.

e. platelets.

What transports oxygen within the blood?

a. LDLs in plasma

b. albumin in plasma

c. HDLs in plasma

d. enzymes in platelets

e. hemoglobin in red blood cells

The arteries in the body that carry deoxygenated blood are:

a. arterioles.

b. pulmonary arteries.

c. coronary arteries.

d. systemic arteries.

e. all small arteries.

A heart attack can best be described as:

a. a sudden, harmful contraction of the heart muscles.

b. an invasion of heart tissue by pathogens such as bacteria.

c. a death of cells in the heart brought about by blockage of a coronary artery.

d. a failure of the nervous system to bring about heart contractions.

e. a rapid, harmful expansion of blood volume supplied by the heart.

Blood returns to the heart (select all that apply):

a. through capillaries feeding into venules.

b. through venules feeding into arteries.

c. by force of contractions of the heart’s left ventricle.

d. by force of contractions of the heart’s right ventricle.

e. by force of skeletal muscle contractions.

The two-way exchange of substances between blood cells and body cells occurs only along the length of the blood vessels called:

a. capillaries.

b. arteries.

c. arterioles.

d. veins.

e. venules.