In a step by step format, write about the process of the blood flow as it enters the heart until it leaves the heart. It should be at least 150 words.

Blood enter the right atrium of the heart via the vena cava (superior and inferior)

The right atrium contracts to push the blood into the right ventricle through the triscupid valve

The contraction of the right ventricle pushes the blood through the pulmonary valve to the pulmonary artery which carries it to the lungs to be oxygenated

After oxygenation, the pulmonary vein brings blood to the left atrium

Contraction of the left atrium pushes the blood through the mitral valve into the left ventricle

The left ventricle contracts to push the blood through the aortic valve, into the aorta, which carries the blood through the body.

Explanation:

a- all cells come from pre-existing cells