Endochondral Ossification

Question 1

What bones are formed through endochondral ossification?

Answer 1

Most bones are formed this way

Question 2

What is the function of mesenchyme in endochondral ossification and where does it take place?

Answer 2

• Mesenchyme creates Cartilage model, which gets replaced by bone.
• The replacement begins in middle (diaphysis) of long bones & follows in ends (epiphyses)

Question 3

Explain the five stages of endochondral ossification

Answer 3

1. Chondrocytes at the center of the growing cartilage model enlarge and then die as the matrix calcifies.
2. Newly derived osteoblasts cover the shaft of the cartilage in a thin layer of bone.
3. Blood vessels penetrate the cartilage. New osteoblasts form a primary ossification center.
4. Bone of the shaft thickens, and the cartilage near each epiphysis is replaced by shafts of bone.
5. Articular cartilage, Epiphyseal cartilage and secondary ossification center are formed.