1. Skeletal System
    Includes the bones of the skeleton and cartilages, joints, ligaments and other connective tissues that stabilize or connect them.
  2. Primary Functions of Skeletal System
    • 1. Support
    • 2. Storage
    • 3. Blood cell production
    • 4. Protection
    • 5. Leverage
  3. Bone
    Supporting connective tissue that contains specialized cells and a matrix that consists of extracellular protein fibers and a ground substance.
  4. Four General Shapes of Bones
    Short (Carpals) Long (Humerus) Flat (Skull) Irregular (Vertebra)
  5. Diaphysis
    Central shaft of long bone that surrounds marrow cavity
  6. Epiphyses
    The expanded section at each end of a bone, which is covered by articular cartilage.
  7. Two Types of Bone Tissue
    Compact and spongy (cancellous). Compact bone is relatively solid whereas spongy bone resembles a network of bony rods or struts separated by spaces.
  8. Endosteum
    Inner surface of bone
  9. Periosteum
    Outer surface of bone. The fibers of tendons and ligaments intermingle with those of the periosteum
  10. Osteocytes
    Bone cells
  11. Osteon
    The basic functional unit of compact bone, also called the Haversian System contain blood vessels. 
  12. Structure of Bone
    Image Upload 1
  13. Canaliculi
    Small channels that radiate through the matrix, and interconnect lacunae and link them to nearby blood vessels
  14. Perforating Canals
    Perpendicular channels in a bone to link blood vessels together
  15. Lamellae
    Small sheets of calcified matrix which wrap around blood vessels
  16. Lacunae
    Small pockets in the bone found between sheets of calcified matrix
  17. Requirements for Normal Bone Growth
    • Vitamin D3
    • Calcitriol
    • Vitamin A
    • Vitamin C
  18. Osteocytes
    Mature bone cells. Maintain normal bone structure by recycling the calcium salts in the bony matrix around themselves and by assisting in repairs.
  19. Osteoclasts
    Giant cells with 50 or more nuclei. Dissolve the bony matrix and release the stored minerals through osteolysis. 
  20. Osteoblasts
    Cells responsible for the production of new bone, a process called osteogeneration. When an osteoblast becomes completely surrounded by calcified matrix, it differentiates into an osteocyte. 
  21. Ossification
    The process of replacing other tissues with bone
  22. Endochondral Ossification
    Bone replaces cartilage. 
  23. Epiphyseal Plates
    "Growth plates" that sit at ends of bone and increase the length of the developing bone. When sex hormone production increases at puberty, bone growth accelerates dramatically and osteoblasts begin to produce bone faster than epiphyseal cartilage expands. 
  24. Vitamin D3
    Processed in the liver into calcitriol, which is a hormone that stimulates the absorption of calcium and phosphate ions in the digestive tract.
  25. Role of Calcium in Bones
    Typical body contains between 1-2kg of calcium, 99% of which is deposited in skeleton. If levels of calcium increase by 30% neurons and muscle cells lose responsiveness. An increase of 30% causes excitability to the point of convulsions. A 50% increase usually causes death. Hormones parathyroid hormone and calcitriol increases serum calcium. Calcitonin depresses serum calcium.
  26. Bone Injury and Repair Steps
    • 1. Extensive bleeding. After several hours a clot forms. 
    • 2. Internal callus forms as a network of spongy bone unites inner and outer edges. 
    • 3. Cartilage of external callus has been replaced by bone. 
    • 4. Osteoblasts and osteoclasts remodel the bone back to its original shape. 
  27. Sprains
    • An injury that stretches or tears one or more ligaments within a joint. 
    • Grade 1. Minor and incomplete tear. 
    • Grade 2. Significant but incomplete tear. 
    • Grade 3. Complete tear and total failure of the ligament or ligaments involved. 
  28. Subluxation
    Also called a partial dislocation, is a partial displacement of a bone end from its position within a joint capsule. 
  29. Salter Harris Classifications of Growth Plate Injuries
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  30. Types of Fractures
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  31. Common Extremity Fractures
    • Colles Fracture: Distal radial fracture resembling a fork.
    • Supracondylar Fracture: Distal humerus superior to epiphysis. 
  32. LeFort System of Classifying Facial Fractures
    Image Upload 4
  33. Osteopenia
    Inadequate ossification
Card Set
Skeletal system, ch. 6