Biochemically, bone is composed of inorganic elements (65%) and organic elements (35%).
A. Inorganic component: Mineral “calcium hydroxyapatite [10Ca:6(PO4):(OH)3]”. Bone that is unmineralized is known as “osteid”.
B. Organic component: Bone cells and matrix proteins
a. Bone forming cells:
i. Osteoprogenitor cells:
- pluripotent mesenchymal stem cell
- present in the inner portion of the periosteum, in the endosteum, and in the central canal of compact bone
- stimulated by TGFβ for differentiation …

Osteoporosis is a condition in which the bones are weakened due to a decrease in the bone mass that makes up the skeleton.Throughout life, bones are continuously remodeled. While a child is growing, the rate of bone formation is greater than the rate of bone breakdown. The skeletal mass continues to increase until ages 20 to 30. After that, the …