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The cardiovascular system refers to the
heart, blood vessels and the blood.
Blood contains oxygen and other
nutrients which your body needs to
survive. The body takes these essential
nutrients from the blood. At the same
time, the body dumps waste products like
carbon dioxide, back into the blood, so
they can be removed. The main function
of the cardiovascular system is
therefore to maintain blood flow to all
parts of the body, to allow it to
survive. Veins deliver used blood from
the body back to the heart. Blood in the
veins is low in oxygen (as it has been
taken out by the body) and high in
carbon dioxide (as the body has unloaded
it back into the blood). All the veins
drain into the superior and inferior
vena cava which then drain into the
right atrium. The right atrium pumps
blood into the right ventricle. Then the
right ventricle pumps blood to the
pulmonary trunk, through the pulmonary
arteries and into the lungs. In the
lungs the blood picks up oxygen that we
breathe in and gets rid of carbon
dioxide, which we breathe out. The blood
is becomes rich in oxygen which the body
can use. From the lungs, blood drains
into the left atrium and is then pumped
into the left ventricle. The left
ventricle then pumps this oxygen-rich
blood out into the aorta which then
distributes it to the rest of the body
through other arteries. |
