
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