Introduction of Osteology
Introduction of Osteology include definition and general classification of skeleton. Osteology is the study of bones. Bone is the hardest structure in the body excepting teeth.
Bones support and protect the tissues of the body and form the framework or skeleton of the body. They also act as levers to which muscle or their tendons are attached and serve as parts of loco-motor apparatus. It serves as a storehouse for calcium in the body. In addition, the bone marrow found inside the bones forms one of the important sources of blood corpuscles
The skeleton is generally classified as-
- Exo-skeleton
- Endo-skeleton
Exo-skeleton
Exo-skeleton found on the surface of the body. It is characteristic of invertebrates. In higher vertebrates, it is represented by nails on the digits, horns, hooves, etc., seen in some of the mammals and also shell of crab and tortoise.
Endo-skeleton
Endo-skeleton found embedded in soft tissues within the body. It forms the supporting framework consists of two parts:
- Axial skeleton: Consisting of the skull, the vertebral column, ribs and sternum.
- Appendicular skeleton: Consisting of the bones in the pectoral (forelimb) and pelvic (hind limb) limbs.
In addition to this arrangement of bones, small bones occur in the tissues of an organ or other structures, which do not form a part of the regular skeleton. These small bones are called Heterotropic bones and occur only in particular sites in particular species of animals only.
Examples of Heterotropic bones
os cordis – in the heart of cattle
os penis – in the penis of the dog, also in bats, rodents and some primates
os rostri – in the snout of pigs
os phrenic – in the diaphragm in camels.
(The term splanchnic or visceral bone is also used to refer these heterotropic bones)
Bone
Bone is a hard structure, appears yellowish-white in colour in a fresh dead bone. While in the living animal, it appears bluish pink. It is hard and rigid in macerated and prepared bones, but in the living animals, the rigidity is combined with a certain degree of flexibility also. They function to move, support, and protect the various organs of the body, produce red and white blood cells and store minerals.