Red Blood Cells carry oxygen around the body

They also make your blood look red because 45%

of your blood is made up of Red blood cells, 4% is

white blood cells and the left over 49% is made up

of plasma. Plasma is 90% water and 10% blood.

The Circulatory System

What Do Arteries and Veins do?

Arteries: Pump the blood around the

body. The blood that the arteries carry

round is full of oxygen as it has just

come from the lungs. After the arteries

have come from the lungs they go to

the body's tissues.

Veins: Veins have much thinner

walls than arteries. The veins carry

deoxygenated blood back

to the heart.

What is the function

of the capillaries?

They are the smallest blood vessels

in the body. They let water, 02, Co2 and

other waste substances exchange between blood and surrounding tissues.

Blood

Veins

The heart pumps blood

around the body.

Why are Veins blue?

Veins appear blue due to light wavelengths being filtered differently by the skin.