Thursday, Jan. 21

The human heart is an organ that pumps blood throughout the body supplying oxygen, nutrients, blood, and hormones to and from the tissues removing _________ ___________ and other wastes.

• hydrogen dioxide
• carbon moxoide
• water molecules
• carbon dioxide

Oxygen deprived blood enters the heart through the 

• right ventricle 
• left ventricle
• right atrium
• left atrium

On and off switches to let blood in and out of the heart are known as

• ventricles
• valves
• buttons
• pulses

Veins carry blood _________  the heart.

• back to 
• away
• parallel

Capillaries join together

• veins and arteries
• veins and the heart
• arteries and veins
• heart and valves