Explain the structure and the functions of the different parts of the heart

The heart plays important roles in supplying oxygen and removing toxic waste to/from our body. In basic concepts, the heart is made up of 4 chambers, two on the top and two at the bottom, the top are known as the atria and the bottom are known as ventricles which are separated a flappy muscle called valves. The valve is pressure controlled to allow/prevent the passage of the blood into the ventricles when necessary. The right atria receives deoxygenated blood from the body, the blood passes through the mitral valve down the pressure gradient into the right ventricle that pumps it through the xxx into the lungs. Exchange of oxygen and waste occurs in the lungs to "regenerate" oxygenated blood that travels back into the left atrium of the heart and into the left ventricle bypassing the bicuspid valve. Then, the contraction of the left ventricle generates a high pressure that empties the blood inside the heart into the aorta which is then transported to rest of the body to supply the necessary nutrients and oxygen for cell respiration and metabolism. The cycle is repeated.