Bone & Cartilage Development - Anatomy & Physiology

BACK TO DEVELOPMENTAL BIOLOGY

Introduction

Osteogenesis is the formation of bone. Bone forms from one of three lineages; the skull forms from neural cest; the limb skeleton forms from lateral plate mesoderm; and the axial skeleton forms from paraxial mesoderm (sclerotome). There are two methods of osteogenesis. Both involve the transformation of pre - existing mesenchymal tissue into bone.

1. Intramembranous Ossification - direct conversion of mesenchymal tissue into bone. Occurs in production of the skull.
2. Endochondrial Ossification - mesechymal tissue first differentiates into cartilage, then into bone. This occurs in the production of limb and axial skeleton.
   • Limb cartilage is produced in a proximal to distal direction as a continuous structure. It becomes punctuated with joints later, and then converted to bone.