The heart is made of muscle and haschambers, on each side. The left side containsblood and the right side containsblood. The wall of the left ventricle isthan the wall of the right ventricle because it has to pump blood to the. Deoxygenated blood from the body enters the heart through thebringing blood from the top of the body andbringing blood from the bottom of the body. From there it passes through theand through theinto the. It then flows through theto the lungs where it receives oxygen. Oxygenated blood then flows black through theinto the . It then flows through theinto theand out through thevalve into theto the rest of the body. Arteries carry bloodfrom the heart while veins carry bloodthe heart. The blood in arteries iswhile in veins, the blood is. One exception to this rule is theand.