Bone Tissue

  1. Bone tissue functions
    • rigid support
    • protection
    • aid in movement
    • site of blood cell formation (hematopoiesis)
    • storage for chemicals (calcium)
  2. Types of bone cells
    • osteocytes
    • osteoblasts
    • osteoclasts
  3. Osteocytes
    mature bone cells, reside in lacunae, develop from osteoblasts that have become surrounded by matrix (maintain bone matrix)
  4. Osteoblasts
    • cells that produce fibers and ground substance
    • secrete a matrix (osteoid)
    • eventually they secrete enough to surround themselves in a lacunae and become osteocytes
    • Found on the surface of any developing bone area
  5. Osteoclasts
    • large, multinuclear phagocytic cells capable of degrading and reabsorbing matrix
    • appear to be derived from bone marrow cells
    • found on surface of bone area being reabsorbed
    • NOT a progression of osteocytes
  6. Bone matrix
    made up of organic and inorganic substances
  7. Organic substances in bone matrix
    • collagen fibers
    • ~1/3 - flexibility and tensile strength
  8. Inorganic substances in bone matrix
    • hydroxyapatite crystals made of calcium phosphate, calcium carbonate, and calcium hydroxide
    • ~2/3 - compression strength
  9. Types of bone tissue
    • compact (dense) bone
    • spongy (cancellous) bone
  10. Compact (dense) bone
    • found on surface of all bone tissue and provides rigid support and strength
    • components arranged by Haversian system, which includes the osteon as the basic function and structural unit
  11. Osteon
    • basic functional and structural unit of dense bone tissue found in the Haversian system.
    • Components include lacunae, caniliculi, lamellae, central (Haversian) canal, and perforating (Volkman's) canal
  12. Lacunae
    space for osteocyte
  13. Caniliculi
    minute canals radiating in all directions from lacunae allowing for communication between adjacent osteocytes
  14. Lamellae
    concentric, ring like arrangement of layers of bone tissue
  15. Central (Haversian) canal
    contains blood vessels and nerves
  16. Perforating (Volkman's) canal
    perpendicular channels connecting Haversian canals
  17. Spongy (cancellous) bone
    • bone tissue characterized by forming trabeculae (spicules)
    • contains red bone marrow in heads of humerus and femur, vertebrae, sternum, pelvis, and cranial bones.
  18. Trabecula (in spongy bone tissue)
    • refers to the lattice-like arrangement of bone tissue found deep to compact bone
    • localized to epiphyses (ends) of long bones and in short, flat, irregular bones
Card Set
Bone Tissue
Anatomy bone tissue