Intramembranous ossification

Endochondrial ossification

Endochondral ossification

forms the

____ bones

Intramembranous ossification

forms the

________ bones

Flat bones of the skull

Some of the facial bones (zygomatic & maxilla bone)

Mandible

[image]Central[image] part of the clavicle[image]

Endochondral Ossification

Bone eventually replaces cartilage  EX for in the

_______________, & _________________ 

1)The fetal hyaline cartilage of bone forms

1a) Chodrocytes enlarge(hytrophy) and then die b/c

2) Cartilage calcifies, and a periosteal bone collar forms around the diaphysis

3) Primary ossification center forms in the diaphysis

4) Secondary ossification centers form in the epiphyes

5) Bone replaces cartilage  EX for in the 

(articular cartilages, & epiphyseal plates)

6) Epiphyseal plates ossify and form epiphyseal lines

In Endochondrial ossification

Medullary cavity

(in middle of long bone)

• All mature bone is formed in layers called lamellae.  
• Within the lamellae are small spaces, or lacunae, in which osteocytes reside.
• Neighboring lacunae are interconnected by thin channels, or canaliculi.
• In compact bone, the lamellae are organized into sets of concentric rings called osteons or Haversian systems.
• Each osteon includes a central channel, the Haversian canal, which contains a blood vessel. 
• The lamellar systems (osteons) of bone are continually being remodelled.