Answer to Question #188346 in Human Anatomy and Physiology for Jerrisha

Question

What are the bone changes on a macro and cellular level

Answer 1

The change in shape, position, and size of bones takes place through the process namely modeling and remodeling of bones. The size and shape of bones change when the bone is formed in one place and gets disintegrated in another place which is known as modeling. Cells in this site are removed and replaced by the process of remodeling. 

During the growth of an individual, bones are altered by modeling where new bones are formed in one location and the old bones are broken down in another location of the same bone allowing growth and expansion on bones. For instance, during puberty, the bones become thicker due to the resorption on both the inner and outer surfaces of the bones. This makes them reach the best-required shape to perform the necessary function. 

In remodeling, a small quantity of bone on the surface of trabeculae or in the interior of the cortex is broken down and replaced. Remodeling does not change the shape of the bone but prevents the over-accumulation of old bone. Osteoclasts are the cells involved in breaking down bones and osteoblasts are the cells involved in the formation of bones, in both modeling and remodeling.