Human Beings – Human Skeletal System
The human skeletal system consists of 206 bones which are supported and supplemented by muscles, cartilages, tendons and ligaments. The human skeleton is classified into two distinct parts, namely:
    1. Axial skeleton
    2. Appendicular skeleton

1. Axial Skeleton
It consists of bones of skull, vertebral column and chest.
•    Skull : The human skull has 22 bones of which 8 are present in the cranium and 14 on the face. These bones protect the brain and sensory organs.

•    Vertebral Column : It is made up of 33 ringshaped bones which are called vertebrae. These bones are arranged as follows.

•    Chest Bones : The first seven pairs of ribs join the vertebral column at the back and the sternum in front as shown in Fig. The next three pairs of ribs are attached to the seventh pair. The rest of the two pairs of ribs are free. Hence these are known as floating ribs. Chest bone and backbone together form a box called the rib cage. Some important internal parts of our body like the heart and lungs are protected by the rib cage.