ANATOMY

Detailed explanation-1: -Blood enters the right atrium and passes through the right ventricle. The right ventricle pumps the blood to the lungs where it becomes oxygenated. The oxygenated blood is brought back to the heart by the pulmonary veins which enter the left atrium.

Detailed explanation-2: -The left atrium receives oxygenated blood from the lungs. The right atrium receives deoxygenated blood returning from other parts of the body. Valves connect the atria to the ventricles, the lower chambers.

Detailed explanation-3: -Blood headed for the right heart has just delivered oxygen and nutrients to the body. Because it has less oxygen, this blood is called deoxygenated (oxygen-poor) blood (shown in blue). The right heart pumps this blood to the lungs where it picks up additional oxygen.

Detailed explanation-4: -Pulmonary veins move the blood oxygen-rich blood to the left side of your heart. The aorta (the main artery in your body) carries the blood from the left side of your heart to the rest of your body through many branches of arteries.