Introduction to the Skeletal System

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• Introduction to the Skeletal System Bone
  Tissue (Chapter 6)

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In addition to bones, the skeletal system
includes cartilage, tendons (connect bones to
muscles), ligaments (connect bones to bones)
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Functions of the Skeletal System

• SUPPORT
• PROTECTION
• MOVEMENT
• STORAGE OF MINERALS
• BLOOD CELL FORMATION

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Classification of Bones
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Features of a Long Bone

• Epiphysis (head) - end of the bone
• Diaphysis (shaft) - surrounds the marrow cavity
• Epiphyseal plate - layer of cartilage allowing
  bone to grow in length when bone stops growing,
  cartilage is replaced by bone - epiphyseal line
• Articular Cartilage - reduces friction, absorbs
  shock, and allows for smooth movement

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Bone Histology

• Connective tissue
• Dense matrix primarily made of collagen and
  hydroxyapatite - Ca10(PO4)6(OH)2
• Matrix contains bone cells
• Osteogenic cells undergo cell division and
  become osteoblasts
• Osteoblasts form new bone
• Osteocytes mature osteoblasts maintain
  bone
• Osteoclasts break bone down

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Osteoblasts, Osteocytes, Osteoclasts
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Types of Bone Tissue

• Spongy
• Irregular lattice of thin columns trabeculae
• Trabeculae reduce weight, protect red bone marrow
• Trabeculae are oriented along lines of stress
• Compact
• very dense strong
• most of the bone mass in the body

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More about the Compact Bone
Osteon basic functioning unit of compact
bone Central canal contains blood vessels
nerve Lacunae spaces that house osteocytes
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Osteon (Haversian System)