What is the main difference between intramembranous ossification and endochondral ossification?
In intramembranous ossification, bone develops directly from sheets of mesenchymal connective tissue. In endochondral ossification, bone develops by replacing hyaline cartilage. Activity in the epiphyseal plate enables bones to grow in length.
What determines whether intramembranous or endochondral ossification occurs in fracture healing?
Intramembranous ossification, mediated by the periosteal layer of bone, occurs with the formation of callus. For endochondral ossification, deposition of bone only occurs after the mineralised cartilage.
What happens during Intramembranous ossification?
In intramembranous ossification, a group of mesenchymal cells within a highly vascularized area of the embryonic connective tissue proliferates and differentiates directly into preosteoblasts and then into osteoblasts. These cells synthesize and secrete osteoid which is calcified to become woven bone.
Is Endochondral an ossification?
Endochondral ossification is the process by which the embryonic cartilaginous model of most bones contributes to longitudinal growth and is gradually replaced by bone.
What is the process of intramembranous ossification?
Intramembranous ossification is the process of bone development from fibrous membranes. It is involved in the formation of the flat bones of the skull, the mandible, and the clavicles. Ossification begins as mesenchymal cells form a template of the future bone.
What are the steps of intramembranous ossification?
1 – Intramembranous Ossification: Intramembranous ossification follows four steps. (a) Mesenchymal cells group into clusters, differentiate into osteoblasts, and ossification centers form. (b) Secreted osteoid traps osteoblasts, which then become osteocytes. (c) Trabecular matrix and periosteum form.