Bones, Joints and Muscles The skull helps protect the brain. Ball-and-sockets joints protect the eyes. The backbones protect the spinal cord. The ribs form a protective cage around the heart and lungs. The pelvic bones support our body when we sit. The bones in our body are also connected with each other. The point where two bones meet and connect is called joint. Our joints and muscles allow our bones to move. The movements of our body originate in our joints. Muscles form the fleshy parts of the body. They enable our body to move. They also give shape and forms to our body and protect delicate organs. Muscles are voluntary or involuntary.