Bony tissue
Connective tissue of the human skeleton
High organic content = strength
Types
Compact bone
Spongy bone
Good blood supply
Components
Cells
Osteocytes
Mature osteoblasts
Osteoblasts form bony matrix
Oval cells with thin processes
Adjacent cells in contact
Exchange nutrients
Lacuna
Osteocyte inside bony matrix
Canaliculi
Process inside bony matrix
Osteoclasts
Remodelling of bone
Resorption of bone matrix
Large number of nuclei
Leave cavities and grooves in bone
Howship's lacunae
Architecture
Compact bone
Shaft long bone
Laminar
=layers
Around blood vessels
4 types
Haversian system
most common
Haversian canal
blood vessels and nerves
Parallel long axis
lamellae
Concentric circles
demarcated by lacunae
Canaliculi join lacunae
Other 3 around and between HS
Inner circumferential lamellae
Outer circumferential lamellae
Interstitial lamellae
Periosteum
Regular dense connective tissue
Endosteum
Reticular connective tissue
Growth
Appositional
Intramembranous
aggregation of mesenchymal cells
mesenchymal cells
aggregate
membrane
differentiate
osteoblasts
secrete osteoid
cells separate
osteocytes
attached thin cytoplasmic processes
canaliculi
bone matrix
calcified
bone spicules
surrounding mesenchyme
proliferate
osteoprogenitor cells
in apposition to bone spicules
osteoblasts
more bone
trabecular network in shape of bone
Endochondral
Cartilage model
Mesenchymal cells aggregate
differentiate
chondroblasts
cartilage matrix
cartilage model
zones
Resting zone
Hyaline cartilage
Proliferation zone
Chondrocytes divide rapidly
Form columns of stacked cells
Maturation zone
Large chondrocytes
Matrix resorbed
Calcification zone
Death of chondrocytes
Remaining matrix calcified
Ossification zone
Endochondral bone appear
Resorption zone
