MICROANATOMY

Detailed explanation-1: -Mesenchymal cells differentiate into chondrocytes and form the cartilage model for bone.

Detailed explanation-2: -As the cartilage cells die, a group of cells that have surrounded the cartilage model differentiate into osteoblasts. The ostoblasts begin forming bone matrix on the partially degraded cartilage (Bruder and Caplan 1989; Hatori et al. 1995). Eventually, all the cartilage is replaced by bone.

Detailed explanation-3: -Endochondral bone formation occurs when hyaline cartilage is used as a precursor to bone formation, then bone replaces hyaline cartilage, forms and grows all other bones, occurs during development and throughout life.

Detailed explanation-4: -During embryonic development, precursor chondroprogenitor cells condense in a specific area and become cartilage-forming cells known as chondrocytes, which form the cartilage model of the bone (Fig. 2).

Detailed explanation-5: -Osteoblasts, bone lining cells and osteoclasts are present on bone surfaces and are derived from local mesenchymal cells called progenitor cells.