To understand the mechanisms of a disease (Paget's disease, etc.) of bone tissue and bone at all, should carefully examine what the bone and the bone itself.
Bone - is a specialized connective tissue, which, like all the connective tissue contains cells and the extracellular matrix. Extracellular matrix consists of organic and inorganic material.
The organic part consists of proteins, of which 95% is type I collagen, is part of the fibrils. Non-collagenous proteins - is osteocalcin, osteonectin and osteorontin. Inorganic material is formed by calcium, phosphate, magnesium, hydroxyapatite. Cellular component represented by osteoblasts, osteocytes, osteoclasts.
This process is called "remodeling", or "bone turnover". Violations of the cycle of remodeling or regulation of the activity of bone cells leads to metabolic bone disease, including osteoporosis, hyperparathyroidism, neoplastic processes in bone, osteomalacia, Paget's disease.
Paget's disease is characterized by uncontrolled rapid restructuring of the bone with an increase in osteoclastic activity that exceeds the increase in the activity of osteoblasts, so is an infringement of the formation of new bone. As a result of Paget's disease bone thickens, deformed, there are bone pain, pathological fractures.
Paget's disease develops in persons over 40 years and most often affects the pelvis, femurs, spine and skull.
Paget's disease may be asymptomatic and detected by accidental detection of high alkaline phosphatase activity in serum.