Please enable JavaScript.

Coggle requires JavaScript to display documents.

Skeletal system (Functions (Locomotion (extension: backward lifting of arm…

- - - - Hard, connective tissue made up of cells (osteocytes: trapped in lacunae in organic bone matrix [osteoid] and made from osteoblast. Transfer calcium ions to osteoid; osteoblast: cells involved in synthesising new bone matrix [bone formation] and osteocytes and osteoclast: secrete hydrochloric acid to dissolve hydroxyapatite to release calcium & phosphorus into extracellular matrix & enzymes to digest bone matrix [bone resorption]) and mineralised matrix containing organic substances eg protein fibres (collagen) and inorganic molecules eg hydroxyapatite and calcium carbonate.
    - - Bone cells
        
        Spongy bone: found in interior of skull bones, vertebrae, sternum, pelvis and ends of long bones. Resembles a sponge due to the presence of bone marrow cavities between trabeculae beams/bone plates containing red bone marrow. Contains bone trabeculae that is porous (marrow cavities - resembles white spaces).
        
        Compact bone: found at outer layer of bones and shafts of long bones. Made up of osteon subunits (cylindrical structures made up of phosphorus and surrounded by concentric layers of connective structures/lamallae enclosing the central/Haversian canal which contains the nerves and blood vessels. Each lamallae is made up of bone cells (osteoblast and osteoclast "floating" at the periphery with osteoclast being a group of small darkly-stained circles in an ovoid and osteocytes in the trabeculae) and surrounded by canaliculi (network of small canals for nutrient and metabolic waste exchange). Each osteon is separated from the other by interstitial lamallae and are connected to each other by oblique channels (Volkmann canals). The bundles of osteon are surrounded by the inner and outer circumferential lamallae (periosteum).
  - - - cartilaginous joint: joints connected with cartilage eg symphysis pubic and at intervertebrae discs
      - synovial joint: most mobile eg shoulder and knee joint
        
        made up of 2 articulating bones with articulating membrane at the joint cavity, with synovial fluid (lubricates joints and cushions impact) and surrounded by the synovial membrane and joint capsule at the sides. Thin layer of cartilage at joint cavities to lubricate and absorb shock.
        Eg
        1) Ball and socket joint: shoulder & hip joint
        2) Hinge joint: elbow (ulna & humerus), knee (femur & tibia) & ankle joints
        3) Pivot joint: wrist joint
      - Fibrous: rigid joints with no joint cavity and connected via fibrous connective tissues eg suture between skull plates eg occipital, temporal & parietal plates