Skeleton

When construction workers begin to erect a new multi- story building, they first construct a frame of large steel girders.Then they add the walls, ceilings and floors. The entire building is supported by that strong steel frame.
Your body, too, has a strong frame. It is made up of two hundred large and small bones, firmly attached to one another. Together they make up the skeleton, the body`s reliable support.
The bases of your arms and legs are very durable bones to which the muscles are attached by tendons. These bones are connected to one another by joints. On the joints your arms, legs, fingers and trunk easily turn right and left, and bend forward and backward.
The lungs and heart are surrounded by the bony rib cage. It consists of twelve pairs of very strong but flexible ribs. Seven pairs of these ribs are attached to the spine at one end and to the narrow sternum at the other.…