Types of Bones

Bones which the length exceeds their width and consists of a diaphysis  or a shaft composed mainly of a compact bone, a metaphysis. A flared portion at the end of the diaphysis consisting mainly of cancellous spongy bone and two extremities, each called an epiphysis, seperated from the metaphysis by a epiphyseal line where longituinal growth occurs. The shaft consists of spongy bone, it is thickest in the middle as that it where the biggest strain is placed. The shaft is curative as it helps disturbute weight. The meduallry cavity is filled by yellow bone marrow.   The epiphyses of a long bone are usually broad and expanded for articulation with other bones for to provide a large surface for muscle attachment. Examples of long bones are humerus, radius and ulna. Not obvious examples are the metacarpals of the hand and metatarsals of the foot.

Short bones lack a long axis and have an irregular shape. They consist of a thin layer of compact tissue over a majority of spongy or cancellous bone. Examples of this are carpal bones of the wrist and the tarsal bones of the foot

Flat bones are thin bones found whenever there is a need for extensive muscle attachment for protection for soft or vital parts of the body. These bones are usually curved, consist of two flat plates of compact bone tissue enclosing a layer of cancellous bones. Examples of these bones, sternum, ribs or scapula.

Irregular bones are of a peculiar and different shape. They consist of spongy bone enclosed by thin layers of compact bone. An Example would be vertebrae and ossicles of the ears

Sesamoid bones are small rounded bones, these bones are enclosed in a tendon and fascial tissue and are located adjacent to joints. They assist in the fuctioning of muscles. Examples of ths be a Patella. Some of the bones in the wrist can be classfied as sesamoid bones and short bones as well.