Osteogenesis
g
Intramembranous ossification
Mesenchymal osteoblast
Secrets osteoid

Endochondral ossification
Hyaline cartilage eroded
Osteoblast invade

Osteogenesis imperfecta:
 ↓Collagen
C ll
I
 Defecte collagen I
 fracture
Intramembranous ossification
In flat bone

condensed layer of Embryonic mesenchym

Ossification centers

Progenitor cell differentiation

Osteoblast around vessels

Osteoid secretion

Calcification

Woven trabecula formation

Lacuna formation

Ossification centers fusion

Compact bone surrounded spongy bone

Remaining connctive tissue forms:
Endosteum
periosteum


Stages of
o Intramembranous
t a e b a ous Ossification
Oss cat o
Stages
g of Intramembranous Ossification
Endochondral ossification
 Most
M tb
bones (l
(long b
bones))
 Bone Collar
Stages
g of Endochondral Ossification
Secondary Secondary
ossification center
Hyaline cartilage
Epiphyseal blood vessel
Deteriorating Deteriorating
cartilage matrix
Spongy bone
bone formation
Primary Primary
ossification center
Bone collar
i l
Articular cartilage
Spongy bone
Medullary cavity
Epiphyseal plate cartilage
Blood vessel of periosteal bud
1 Formation of Formation of
bone collar around hyaline cartilage model.
2 Cavitation of the hyaline cartilage within the cartilage model.
3 Invasion of internal cavities by the periosteal
by the periosteal bud and spongy bone formation.
4 Formation of the medullary cavity as medullary
cavity as
ossification continues; appearance of secondary ossification centers in the epiphyses in preparation f
for stage 5.
5 Ossification of the O ifi ti
f th
epiphyses; when completed, hyaline cartilage remains only in the epiphyseal plates and articular cartilages
Figure 6.8
Bone g
growth in epiphyses
pp y
Rickets:

In children

Calcium deficiency

Epiphys deformation

Impaired growth

malntririon

Vit. D deficiency
Osteomalacia
O
t
l i

In adult

Impaired calcification

Much decalcification
Bone g
growth,, remodeling
g & repair
p
Metabolic role of bone
PTH
 Calcitonin

Growth hormone
Liver
Somatomedian (IGF)
Epiphysial growth

Pituitary dwarfism
Gi
Gigantism
ti
Acromegaly
Rheumatoid
Rh
id Arthritis
A h ii
Synovial membrane inflammation & thickening
Collagenase & hydrolitic enz.
Cartilage defect
Joints
Synarthrosis
 Diarthrosis

Synarthrosis
1. Synostosis (sutures)
2. Syndesmosis (distsl tibiofibular & sacroiliac j)
3. Symphysis (pubis symphysis)

Joints

Diarthrosis
Joint cavity
Synovial fluid
Synovial membrane
1.
2.
Macrophage like synovial cell (A type)
Fibroblastic synovial cell (B type)