Needed substances are carried to the body cells by

• enzymes

• blood

• food

• water

The function of the atria is to

• pump blood to the lungs.

• pump blood to the body.

• receive blood that comes into the heart.

• deliver oxygen to body tissues.

When blood flows into the right atrium from the body, it contains

• little oxygen and a lot of carbon dioxide.

• a lot of oxygen and little carbon dioxide.

• a lot of both oxygen and carbon dioxide.

• little of either oxygen or carbon dioxide.

Which of these heart structures prevents blood from flowing backward?

• aorta

• valve

• septum

• coronary artery

What causes blood pressure?

• the force with which the ventricles contract

• the rate at which blood flows through the heart

• the speed at which oxygen is returned to blood in the lungs

• the strength of the muscles in the walls of the capillaries

How many loops does the human circulatory system contain?

• 1

• 2

• 3

• 4

What instrument is used to measure blood pressure?

• thermometer

• stethoscope

• sphygmomanometer

• blood bank

When the ventricles contract, blood is pumped

• out of the heart.

• into the heart.

• through the septum.

• into veins

"The right ventricle pumps blood to the lungs"

• True

• False

The cardiovascular system consists of the heart, blood vessels, and lymph.

• Valves

• Red blood cells

• Blood

• Heart rate