• Intramembranous ossification gives rise to membrane bones, these being the flat bones of the skull and parts of the mandible.
  • This process involves the deposition of bone matrix (osteoid) directly in regions ("membranes") of embryonic mesenchyme.

• Bones of the extremities, pelvis and vertebral column (cartilage bones) are formed by endochondral ossification.
  • This process involves the replacement of a hyaline cartilage model with bone. Regardless of the ossification process, the histological structure of the bone is the same.

Learning Objectives:

• Understand the differences and similarities between intramembranous and endochondral bone formation and the key function of the periosteum in bone growth.
• Understand the organization of the epiphyseal growth plate and its role in endochondral bone formation and growth of long bones.
• Understand the structure of a typical synovial joint, including the nature and functions of the synovium.

Let's look at some examples.