CBSE Class 10 Answered

The heart lies in the chest cavity between the lungs. It is composed of four chambers, many large arteries and many veins. The four chambers are called atrium and ventricles. A wall of muscle divides the heart into two cavities: the left cavity pumps blood throughout the body, while the right cavity pumps blood only through the lungs. Two chambers of the heart lie in the left cavity and two chambers lie in the right cavity. The two upper chambers of the heart are called atrium, the bottom chambers are called ventricles.  The right side of the heart receives deoxygenated blood from all parts of the body except for the lungs.  The left side of the heart receives oxygenated blood from the lungs and  pumps it to the rest of the body.