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Cartilage and Bone - Coggle Diagram

- - - - Endosteum
        
        Simple layer of osteoprogenitor
        cells and quiescent osteoblasts
        
        Lines
        
        marrow cavity
        
        Haversian canals
        
        Volkmann's canals
    - - Periosteum
        non-articular
        
        vascularized dense irregular connective tissue
        
        nerves
        
        osteprogenitor cells
      - compact and spongy
      - Hyaline cartilage
        at articular regions NO PERICHONDRIUM
  - - - Inorganic component
        
        70% bone mass
        
        Ca and PO4 in hydroxyapatite
        
        rigidity and hardness
      - Organic component
        
        Collagen I (90%)
        
        rest proteoglycans with GAGs
        (chondroitin sulfate, hyaluronic acid)
        and organic material osteocalcin/nectin/pontin
        
        Elasticity and resilience
    - - Osteoblasts
        
        Secrete Osteoid and mineralize
        
        Single layer on developing
        outer bony surfaces (cuboidal to columnar)
        
        Stimulated by vit D, estrogen
        and growth factors
        
        Become osteocytes
        are non-mitotic
        
        Matrix
        
        Primary (woven/immature)
        collagen in osteoid by osteoblasts
        randomly arranged
        
        Secondary (lamellar/mature)
        replaces primary, collagen in layers
        with all fibers in parallel layer
      - Osteocytes
        
        Long living, surrounded by
        matrix, sitting in lacunae
        
        Project processes to communicate
        (canaliculi)
        
        Maintain matrix (20-30 yrs)
      - Osteoprogenitor
        
        Spindle-shaped
        
        Innermost layer of
        periosteum and
        in endosteum
        
        derived from mesenchymal cells
        
        Differentiate into osteoblasts
        (adipose, chondro/fibroblasts)
        
        Mitotic (quiescent in adult
        except turnover and fracture)
      - Osteoclasts
        
        Huge, multiple nuclei
        
        Live in Howship's lacunae
        
        From macrophage stem cell
        
        matrix turnover
        
        regulated by osteoblasts
        
        Osteoclastogenesis
        
        Inhibited by calcitonin
        (C cells, thyroid, reduce Ca)
        
        Stimulated by PTH
        (parathyroid when low Ca)
        --> M-CSF and RANKL on osteoblasts
        --> osteoclastogenesis (RANK receptor on clasts)
        --> clasts break down bone, release Ca
  - - - spicules/trabeculae
      - lamellae matrix with
        osteons if thick enough
      - diffusion from marrow cavity
    - - Osteons or Haversian systems
        organize blood supply
      - Haversian canals contain blood vessels
        lined by endosteum
      - Osteon concentric arrays of
        linked osteocytes (as many as 20 layers)
      - Volkmann's canals (perforating)
        transversal connect vessels and nerves
        in Haversian canals and linking them
        to sources in periosteum and marrow cavity
  - - - Chase Effect chondrocyte proliferation
        starts at epiphyseal, replaces cartilage
        at diaphyseal side of plate
      - Epiphyseal Plate
        region of cartilage between primary
        and secondary centers of ossification
        
        Zone of resting cartilage (reserve)
        
        chondrocytes randomly distributed
        
        undergo mitosis
        
        Zone of proliferating cartilage
        
        Rapid mitosis, organize into columns
        
        Zone of maturing cartilage (hypertrophy)
        
        Chondrocytes enlargement secrete VEGF
        
        Zone of calcifying cartilage (calcification)
        
        chondro calcify matrix, undergo apoptosis
        
        leaving spaces for ingrowth of blasts and vessels
        
        Zone of ossification (vascular invasion)
        
        vessels penetrate, carry progenitors
        
        blasts lay down osteoid on cartilage matrix
        
        clasts resorb calcified cartilage and
        enlarge marrow cavity
        
        trabecular bone formed
        
        Between epiphysis and metaphysis
        Responsible for growth in length (interstitial)
        
        Appositional growth from periosteum, diameter
        
        Spongy bone, blasts and clasts remodel
        
        important for remodeling as adults
      - Short bones (like carpal)
        
        1 primary center of ossification
        
        Tiny then connect
      - Irregular bones (vertebrae, pelvis)
        
        multiple primary and secondary
        
        Fuse over time
      - Long bones
        
        Primary DIAPHYSIS
        
        hyaline cartilage, hypertrophy of chondrocytes
        
        secrete VEGF --> vascularizes perichondrium
        
        chondrogenic cells --> osteogenic --> blasts
        --> periosteal bone collar formed
        
        Hypertrophic chondrocytes --> apoptosis as calcification
        takes place --> large cavities (marrow)
        
        blood vessels grow through bony collar, bring osteoprogenitors
        
        form blasts, lay osteoid
        
        clasts resorb cartilage/calcified complex
        
        moves toward both epiphyses
        
        Secondary in EPIPHYSIS
        
        sometimes multiple centers
        
        same as primary but hyaline cartilage stays
        at articular surfaces
- - - - Young cartilage
      - Chondrocytes --> mitosis
        give cell nests
      - Chondrocytes secrete
        territorial matrix become
        separated in own lacunae
    - - Inner layer of perichondrium
      - adult cartilage
      - chondrocyte --> mitosis
        secretes matrix
        --> adds new cartilage
  - - - ECM
        More of a glassy look
        Type II and ground subst
      - Perichondrium
        Dense irregular connective
        tissue (outer fibrous layer
        and inner cellular layer
        NOT ON ARTICULAR SURFACES
      - Chondrocytes
        
        oval to round shape
        
        baso cito, round nucleo
        
        Exist in lacunae
        or cell nests
        (isogenous groups)
    - - Elastic fiber in ECM
      - Sme chondrocyte and
        perichondrium as hyaline
    - - A lot of collagen
        with chondrocytes in it
      - NO PERICHONDRIUM