A&P 9

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A&P 9
2012-04-05 11:15:34

skeletal system
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  1. What are the 6 functions of the skeletal system & briefly describe each one
    • support- structural framework, attachment for tendons & ligaments
    • protection- protects internal organs
    • movement- assist in movement
    • mineral homeostasis- keep blood calcium & phosphate w/in normal limits by storing & releasing these minerals
    • hematopoesis- production of blood cells in red bone marrow
    • fat (energy) storage- triglycerides stored in yellow bone marrow
  2. what are the 4 cellular components of BONE TISSUE?
    • osteogenic cell- precursor to other cell types (bone stem cell)
    • osteoblast- forms bone extracellular matrix (bone building)
    • osteocyte- maintains bone tissue
    • osteoclast- breaks down bone (bone chewing)
  3. what are the 2 extracellular components of BONE TISSUE?
    • HYDROXYAPATITE- mostly inorganic portion of bone (cellular matrix), mineral, compound of calcium, phosphate, & hydroxyl goups- Ca10(PO4)6(OH)2
    • COLLAGEN- mostly organic portion of bone, collagen type 1, many minor proteins
    • *MINERAL & ORGANIC components need to work together
    • -mineral alone is too BRITTLE
    • -organic alone is too FLEXIBLE
  4. what comes about when there is TOO MUCH mineral in the bone?
    osteogenesis imperfecta- "brittle bone disease"
  5. what comes about when there is TOO MUCH collagen in the bone?
    • bones are soft & pliable causing:
    • -rickets in children
    • -osteomalacia in adults
  6. describe COMPACT BONE
    • gives bone its strength
    • hard, dense tissue that provides structural support
    • basic structural unit- osteon (how they grow, form, remodel)
    • each osteon consists of series of concentric rings called lamellae, in the center of the structure is a canal (central canal or haversian canal) that runs the length of the bone, carries blood & lymphatic vessels
    • small spaces (depressions) called lacunae, between the lamellae contain the osteocytes
    • small channels, called canaliculi, join adjacent lacunae
    • perforating canals, or volkmann canals, run radially in long bones to join adjacent central canals
  7. describe SPONGY BONE
    • found in marrow cavity (formed from spongy bone) of long bones (femur & humerus)
    • made up of trabeculae (doesn't have an osteon)
    • osteocytes lie in open spaces lacunae
    • canaliculi link the lacunae (communication canals)
    • osteoclasts & osteoblasts lie along surface of each trabecula
    • several loosely organized rings
  8. define TRABECULAE
    spiky projections formed from several loosely organized layers (in spongy bone)
  9. describe what the MARROW CAVITY does in spongy bone
    • red bone marrow- blood cells are made (hematopoiesis)
    • yellow bone marrow- storage of energy as fat
  10. define HEMATOPOIESIS
    process where blood cells are born (in red bone marrow)
  11. what are the 3 types of CARTILAGE?
    • hyaline cartilage- "glassy" resemblance: shiny & translucent- cartilage lining joints & forming much of nose, ribs
    • fibrocartilage- fibrous in appearance & structure- in intervertebral discs, pubic symphysis & meniscus of joints
    • elastic cartilage- similar, but has elastin fibers in place of collagen fibers found in fibrocartilage- in ear & epiglottis (structures that need to be flexible & snap back into shape)
  12. describe DENSE REGULAR connective tissue in the skeletal system
    • found in ligaments (joins bone to bone) & tendons (joins muscle to bone)
    • there is a striated appearance due to oriented collagen fibers
  13. explain DENSE IRREGULAR connective tissue in the skeletal system
    • periosteum- dense irregular connective tissue (thin memebrane) that surrounds bone
    • rich blood supply
    • participates in bone repair
    • nerves- pain
    • is NOT located on articulating surfaces!!
    • it connects ligaments & tendons to bones