Functions of circulatory system
Blood vessels
-Veins branching vessels that carry blood from the capillaries to the Blood vessels are tubes that carry blood throughout the body. The three types are:
heart.
-Arteries carry blood from the heart to the body's living tissue. 
-Capillaries tiny blood vessels between veins and arteries that distribute oxygenated blood to the body.

Parts in our Hearts
A heart is a very important organ that pumps blood throughout the body
There are four main sections of the heart.
-The left atrium 
-The right atrium
- The left ventricle
-The right ventricle