STRUCTURE AND FUNCTION OF THE HEART
The heart has four chambers:
Two artria (auricles) and two ventricles.
The left and right sides of the heart are separated by a muscle wall (septum) so that oxygenated and deoxygenated blood does not mix.
Deoxygenated blood from the rest of the body enters the heart through the vena cava .
Blood enters the right atrium, then through tricuspid valve into right ventricle.
Then via semi-lunar valve to the pulmonary artery to the lungs.
Oxygenated blood from the lungs enters the heart through pulmonary vein.