Bone Formation & Remodeling

Bone Formation The general process when new bone is produced is called ossification. Further development is know as remodeling. This is a continuous process by which bone is created and destroyed.

Ossification The ossification process has two forms. Compact bone begins as cartilage. In cartilage there are bone forming cells called osteoblasts. Theses cells release a gelatin substance called osteoid that combines with minerals and salts to form bone.

Ossification Cancellous (spongy) bones begin as fibrous membranes. The osteoblasts release the osteoid into this membrane. This forms a sponge like bundle of fibers.

Bone Remodeling Bone does not grow by cell division like other tissues. There are two main phases. Think of painting a house or a room Phase 1 Bone reabsorbing cells osteoclasts. Remove the old bone cells (scraping paint off the surface) They do this by releasing acids and enzymes. Phase 2 osteoblasts deposit new bone. (paint over)

Remodeling This process is most active in the early stages of life. Until the age of approximately 35 there is generally more bone forming activity them bone reabsorbing activity. Afterwards the process reverses and there is more bone reabsorbing activity. The result is a loss of 5-10% bone mass per decade.

Fractures Fractures are broken down into two categories. Simple and Compound. Simple fractures the bone is not exposed to the air. Compound factures have exposed bone. These types of fractures are usually more serious and tend to have ligament, muscles and other complications.

Fractures Simple Fracture – a crack or break is detectable but is not severed. Compound – bone breaks into separate pieces. Sometimes called a transverse fracture. From major blows Comminuted Fracture – is when the bone is shattered into pieces. From auto accidents

Fractures

Bone Disease Osteoporosis (porous bone) is a degenerative disease that involves low bone mass and the deterioration of bone tissue. Leads to fractures, especially in the hip, spine and wrist. Women can lose 20 percent of their bone mass following menopause. In 5-7 years. Prevention through: healthy eating (Ca, Vitamin D) Resistance Exercise Healthy lifestyle (non smoking, active) Medical check ups