Inside the heart
The heart is an organ, which is made up of muscle. The muscles allow the
heart to contract and pump the blood around the body.
Within the heart as described there are four chambers; two atria and two
ventricles. Between the atria and the ventricles there are valves, which
⇒ As the image illustrates deoxygenated enters the right atrium and
oxygenated blood enters the left atrium.
⇒ When the ventricle contract the blood enters either the pulmonary artery
( the only artery which has deoxygenated blood) or the aorta, a large
blood vessel, which takes the blood to the rest of the body.
⇒ Between the atrium and ventricle are valves, which prevent backflow back
into the atrium.
⇒ Between the ventricles and the major blood vessels are valves which help
to maintain the pressure and prevent backflow.
⇒ The left ventricle in the heart has thicker walls compared to the right
ventricles because it has to pump blood much further.