The bones present in each species of animal represent modifications from a common pattern as part of evolutionary changes the species or group has undergone.

The bones are highly vascular connective tissue. The bone is supplied with blood externally on the surface and internally on the lining of the medullary cavity.

The surface of the bones presents a number of features in the form of prominences, depressions, perforations etc. These may be articular (forming joints with corresponding articular areas of another bone) or non-articular furnishing attachment to muscles, tendons and ligaments.

Calcium phosphorous, vitamin D, vitamin C, Alkaline phosphatase, parathyroid hormone, growth hormone of pituitary, thyroid hormone and vitamin A are the factors influencing the development and growth of bones.

The bone is one of the varieties of connective tissue, consisting of bone cells or osteocytes, parallel rows of fine collagen fibres, which are embedded in the amorphous ground substance.

Osteology is the study of bones, the hardest structure in the body excepting teeth. Bones support and protect the tissues of the body