The Circulatory System
Veins are what carry the blood
back to the heart but they have
valves so that the cells only go
one way. Because they are under
low pressure, they have thinner
walls than the arteries. The blood
being carried back to the heart
is deoxygenated.
Arteries are what carry the oxygenated
blood from the heart to the different
parts of the body. Because the blood
in the arteries are under high pressure,
the walls are much thicker.
A capillary is a tiny blood vessel
located within the tissues of the
body that transports the blood
from the arteries to the veins.
The circulatory system is
where blood is transported
around the body. Arteries,
veins and capillaries all play
a part in this. The Heart is
where the cycle begins and
ends, as it is the organ that
pumps blood around the
body.