1. The skelton system 




The skelton which is formed by bones and cartilages that unite with another at regions known as joints is the supporting framework of the body, but it also has several other functions. 


          The skelton provides protection for curtain internal , such as the brain, which is inside the skull, and the heart and the lungs which are in the thorax (chest), although the man purpose of the thorax is not to protect but to give a rigid frame within which the lungs can expand and contract during breathing (respiretion).


Bones serve as a system of levers to which muscles are attched, enabling the control of body movemente. They are also storehouse for minerals which are continually entering and leaving the store, and the sites for the formation of new blood cells (through the process of haemopoiesis). 



2.  BONES OF THE SKELTON

    The bones of the adult skelton number 200,or 206 if the three tiny bones of each ear (the auditory ossicles,) are included in the total. They can be divided into the bones of the axil skelton (the head and trunk of the body) and those of the appendicular skelton or limbs vertebrae which form the central backbone of the body, are described below, but detail of other bones are considered when dealing with the appropriate regions. Some parts of certain bones are relatively near the skin surface, and are liable to give rise to pressure sores.