Osteogenesis- Lecture 9/17/21

Question 1

Endochndral bones

Answer 1

Come about using calcified cartilage templates,

• long bones
• thoracic bones
• vertabrae
• Pelvis

Question 2

Membrane (dermal bones)

Answer 2

• De novo bone synthesis

- Flat bones in the skull

Question 3

Periosteal bone collar

Answer 3

First step of endochondral bone synthesis, de novo bone synthesis

Question 4

Steps of bone synthesis

Answer 4

1. Chondrocyte hypertrophy and cartilage calcification
2. Death of chondrocytes which opens tissue for angiogenesis
3. Osteoprogenitor cells follow vessels, become osteoblasts

Question 5

Periosteum

Answer 5

Surrounding tissue of the bone, responsible for growth in girth

Question 6

Primary center of ossification

Answer 6

In the diaphysis, where bone starts growing

Question 7

Secondary center of ossification

Answer 7

In the epiphysis, creates epiphysial plates

Question 8

Epiphysial plate

Answer 8

Growth plates, areas of hyaline cartilage that allow bones to grow in length

Question 9

Zones of growth plate

Answer 9

Resting-> proliferation->hypertrophy-> calcification

Question 10

Mixed spicule

Answer 10

Calcified cartilage core with overlaying bone

Question 11

Bone remodeling

Answer 11

Occurs throughout life and during fracture healing, turns woven bone to lamellar bone

Question 12

Compact bone remodeling

Answer 12

Osteoclasts dig haversian channels, osteoblasts lay concentric circle bone

Question 13

Osteoid

Answer 13

Bone material that is not yet calcified

Question 14

Spongy bone remodeling

Answer 14

Same as compact bone, but no haversian channels, osteoclasts remove woven bone and replace with lamellar

Question 15

Intramembranous ossification

Answer 15

Starts with a condensation of mesenchyme, differentiate to osteoblasts and do de novo synthesis