structure of the Cardiovascular System.

The heart is made up of four hallow chambers.The top two are atria and the bottom two are ventricles.The aria are the reception of the heart and receive the blood. The ventricle are the pumps of the heart which send the blood around the body or to the lungs. The heart is divided into two sides (right and left), each side
having an atrium and ventricle. The sides are divided by a septum.


• Right hand side                                                              

1. When the heart is relaxed, de-oxygenated
blood enters the heart via the venue cavae.

2. Blood enter the right atria.

3. The right atria contracts pushing blood
through the tricuspid valve into the right
ventricle.

4. The ventricle contracts and closes the
tricuspid valve forcing the blood out through
the semilunar valve into the pulmonary
artery to the lungs.

5. The heart relaxes and the semilunar valve
closes to stop back flow.


• Left Hand Side

1. When relaxed oxygenated blood from the
lungs enter via the pulmonary artery.

2. Blood enters the left atria.

3. The left atria contracts pushed blood into
the ventricle visa the bicuspid valve.

4. The left ventricle contracts and closes the
bicuspid valve, pushing the blood through
semilunar valve in the aorta to the rest of
the body.

5. The heart relaxes and the semilunar valve
closes to stop back flow.