DE BIO 141 Chapter 6 - Skeletal System
Chapter Overview
-Bone structure
-Bone formation
-Bone function
-Bone vocabulary and identification
-Bone injury
TOPIC 6.2 - bone formation
Bone Formation
- Occurs during the first weeks of prenatal development; finalized until upper 20’s
- Two types of bone formations:
- Intramembranous - form from connective tissue
- Endochondral - forms from hyaline cartilage
Bones
- Majority of the bones in the body are endochondral in origin
- Develop from hyaline cartilage that begins to break down
- Endochondral ossification
- Intramembranous bones include
- Skul
- Clavicles
- Mandible
- Sternum
- Zygomatic
- Maxillae
- Develop from mesenchyme
- Intramembranous ossification
Intramembranous Formation
- Mesenchymal cells turn into osteoblasts
- Mesenchyme is undifferentiated
dense connective tissue
- Osteoblasts form the ossification center
- Outer osteoblasts lay down the bone matrix
- Inner cells become osteocytes once they
are surrounded
- Found on the lacunae
- Created in the canaliculi
- Spongy bone forms first
- Compact bone is laid down over the spongy
- Outer mesenchyme forms the periosteum
https://open.oregonstate.education/aandp/chapter/6-4-bone-formation-and-development/
