Bone Tissue

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Bone Tissue

• I. Bone Cells
• II. Periosteum
• III. Bone Structure
• IV. Bone Formation
• V. Bone Remodelling
• VI. Synovial Joint Structure

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8 Bone

• Preparation for microscopy
• Ground bone sections (8.2)
• a. dried, no living tissue
• 2. Decalcified preparations (8.4)
• a. removal of inorganic salts
• b. leaves collagen, some ground substance, and
  cells

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I. Bone Cells

• A. Osteoblasts (8.3,8.18)
• 1. located on bone surface
• 2. cuboidal - columnar shape
• 3. basophilic cytoplasm
• 4. secretes osteoid

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I. Bone Cells

• B. Osteocytes (8.1,8.2)
• 1. derived from osteoblasts
• 2. located in lacunae
• 3. cytoplasmic processes in canaliculi
• 4. decreased rER, Golgi
• 5. condensed nucleus

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I. Bone Cells

• C. Osteoclasts(8.3,8.4)
• 1. multinucleated
• 2. located in Howships lacunae
• 3. secretes collagenase and acid
• 4. dissolves boney matrix
• 5. False similarity to megakaryocyte

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II. Periosteum

• A. Outer fibrous layer (8.6)
• 1. collagen and fibroblasts
• 2. Sharpeys fibers anchor periosteum to bone
• B. Inner cellular layer
• 1. osteoprogenitor cells
• 2. capable of mitosis
• 3. forms osteoblasts

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II. Periosteum / Endosteum

• C. Endosteum (8.6)
• 1. located on inner surface of compact boney
  collar
• 2. osteoprogenitor cells

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III. Bone Structure

• A. Types
• 1. compact bone (8.7)
• 2. spongy (cancellous) bone

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III. Bone Structure

• B. Regions of long bone
• 1. epiphysis (8.13)
• 2. metaphysis
• 3. diaphysis
• C. Parts of flat bone
• 1. plates
• 2. diploe

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III. Bone Structure (compact)

• A. Haversian system (osteon) (8.6,8.8)
• 1. Haversian (central) canal
• 2. concentric lamellae
• 3. lacunae canaliculi
• 4. Volkmanns (perforating) canal

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III. Bone Structure

• B. Interstitial lamellae (8.6,8.10)
• C. Inner circumferential lamellae
• D. Outer circumferential lamellae

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IV. Bone Formation

• A. Intramembranous Ossification
• 1. forms flat bones (8.12,8.14)
• 2. mesenchymal cells differentiate into
  osteoblasts
• 3. osteoblasts secrete osteoid
• 4. osteoid becomes calcified
• 5. fusion of boney islands

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IV. Bone Formation

• B. Endochondral Ossification
• 1. forms short and long bones (8.13)
• 2. hyaline cartilage model
• 3. bone replaces cartilage

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IV. Bone Formation

• B. Endochondral Ossification
• 4. growth at epiphysial plate (8.16)
• a. resting zone of hyaline cartilage
• b. proliferative zone
• c. hypertrophic zone
• d. calcified cartilage zone (death of
  chondrocytes)
• e. ossification zone

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V. Bone Remodelling

• A. Normal wear and tear 8-10
• B. Physical stress
• C. Repair
• D. Ca storage and release
• E. Pregnancy
• F. Orthodontia

Interstitial lamellae
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VI. Synovial Joint Structure

• A. Articular surface
• 1. hyaline cartilage
• 2. Lacks perichondrium
• B. Synovial capsule (CT)
• 1. Fibrous layer
• 2. Synovial layer (no epithel.)
• a. secretes synovial fluid
• 3. Ligaments
• a. dense regular CT
• C. Bone
• D. Stability Motility 8.22

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IV. Synovial Joint Structure 8-23