During our adolescent years our bones are evolving to become protracted and broader. Therefore, formation is occurring until we have reached our peak bone mass. The peak bone mass is usually reached by the age of 30; therefore, as we age formation decelerates. Essentially, exercising is an ethical verdict, especially during our matured years.
One of the key elements of regulating skeletal growth is the Osteoclasts. The Osteoclasts are responsible for initiating the bone remodeling cycle. Blood vessels and nerves are able to penetrate the bone once the chondrocytes die allowing Osteoblasts to secret osteoid; this is a protein fiber, into the cavities created by the Osteoclasts. Once the osteoblasts become trapped in the cavities they turn into osteocytes, thus creating spongy bone forms. Then Osteoblasts build compact bone around the already formed spongy bone by secreting their matrix. In conclusion, the osteoclasts digest old bone and the osteoblasts lay down new bone. (describe steps in building bone and talk about spongy bone and compact bone)
Resorption- osteoclasts digest old bone
Reversal- when mononuclear cells appear on the bone surface
Formation- when osteoblasts lay down new bone until the resorbed bone is completely replaced.
Fractures due to the strain caused by repetitive exercise. They are thought to arise from a combination of MUSCLE FATIGUE and bone failure, and occur in situations where BONE REMODELING predominates over repair. The most common sites of stress fractures are the METATARSUS; FIBULA; TIBIA; and FEMORAL NECK.
http://www.ncbi.nlm.nih.gov/pubmed/17308163
The continuous turnover of bone matrix and mineral that involves first, an increase in resorption (osteoclastic activity) and later, reactive bone formation (osteoblastic activity). The process of bone