The main function of the circulatory system is 

• To give the body structure and support
• Excrete waste
• transport blood, nutrients, and gases throughout the body
• to transport messages from the body to the brain

Oxygen rich blood LEAVES the heart from the

• left ventricle

• left atrium 
• right ventricle
• right atrium

Doors to let blood in and out of the heart and maintain unidirectional flow are known as

• ventricles
• valves
• buttons
• pulses

Arteries carry blood _____________ from the heart.

• back to
• away
• parallel

A capillary is an extremely small blood vessel located within the __________ of the body, which allows for gas exchange.

• organelles
• tissues
• cells

The mammalian heart has ___ chambers.

• 1

• 2

• 3

• 4

This chamber of the heart RECEIVES blood returning from the body (from the vena cavas)

• Right Atrium
• Right Ventricle
• Left Atrium
• Left Ventricle

What is pulmonary circulation?

• Blood travelling to and from the lungs
• Blood travelling to and from the body
• A blood clot in the lungs
• The vessel that brings blood to the lungs

True or false:

Arteries always carry oxygenated blood.

• True

• False

The blood in the vena cava is...

• oxygenated, returning to the heart

• deoxygenated, returning to the heart

• oxygenated, leaving the heart

• deoxygenated, leaving the heart