Skeletal system constitutes rigid framework of body upon which all other organs of body are supported. With the help of muscles, tendons, ligaments and joints, the skeletal system provides desired movements of body. Bones are composed of organic soft matrix chiefly collagen and inorganic stiff component chiefly made of calcium phosphate. Mineral contents of bone varies time to time depending upon their nutritive supply and use in the body. Continuous remodeling of bones permits extensive flow of minerals between bone and blood which is physiologically controlled by parathyroid, calcitonin hormones and vitamin D. Apart from providing structural frame work and strength to the body, the skeletal system is also involved in other physiological functions such as synthesis of blood cells, reservoir of calcium and phosphorus.
Bones are held together with the help of joints or articulations that are responsible for providing requisite mobility to the body parts to perform day to day activities. Structure and function of joint depends upon the type of mobility required.