ANATOMY

Detailed explanation-1: -Osteoblasts are cells responsible for the secretion and deposition of bone morphogenetic proteins (BMPs) into the extracellular matrix during bone formation.

Detailed explanation-2: -Osteoblasts in the organized epithelioid structure secrete bone organic matrix, and remain as a tight epithelium to control the matrix environment for mineralization. FIG.

Detailed explanation-3: -Bone Cells: Osteoblasts They are metabolically highly active, synthesizing the collagenous and noncollagenous bone matrix proteins, which are excreted and then deposited between the osteoblasts and the bone surface. This newly built matrix, which is not yet calcified, is termed the osteoid.

Detailed explanation-4: -The cartilage cells die out and are replaced by osteoblasts clustered in ossification centres. Bone formation proceeds outward from these centres. This replacement of cartilage by bone is known as endochondral ossification.