Types of Bones According to mode of Formation and Shape and Size | Essay

Essay on the Types of Bones According to mode of Formation and Shape and Size are mentioned below:

I. According to mode of formation:

1. Cartilaginous or replacing bones:

These bones develop from the pre-existing cartilage. These are also called as endochondrial bones. E.g. humerus, femur.

2. Investing or dermal or membrane bone:

These bones develop in the dermis of the skin as thin plates and sink to get attached over original cartilages. E.g. frontal nasals, vomers, parietals of the skull.

3. Sesamoid bones:

These are small rounded masses of bones formed in tendons at the joints where they are subjected to great pressure. E.g. patella (knee cap), fabellae

4. Visceral bones:

These bones are formed in organs dissociated from the rest of the skeleton. In the heart of some ungulates (ruminates) bones develops in the connective tissue of the cardia C (skeleton) as Os cordis.

5. Spongy bones (Cancellous bone):

Bony matter occurs as bars, whose spaces are filled with red bone marrow. They occur at the end of long bones. E.g. femur, humerus, flatbones, sternum etc.

6. Compact bone:

Compact matrix occurs in the form of lamellae. E.g. clavicles and scapulae of pectoral girdles, armbones, limbbones and innominates of pelvic girdle.

II. According to shape and size:

Type of bone Examples:

1. Long bones: Humerus, radius, ulna, femur, tibia, fibula

2. Short bones: Carpals and tarsals

3. Flat bones: Skull bones, sternum and ribs

4. Irregular bones: Ear ossicles, vertebrae, carpals of wrists and tarsal of ankle.

Submitted by : Dr. Nanda, Category : Essays, Tag : Essay on Bone