CT part 3

  1. Mesenchyme
    loose, primitive CT in embryo

    Function: meshwork to allow cells and fluids to move within an organ

    Components: mesenchymal cells with stellate or spindle-shape, ECM has abundant ground substance for cell and metabolite exchange with vessels and fine fibrillar matrix of reticular fibers
  2. wharton's jelly
    in umbilical cord to resist compression and kinking of cord

    • Components: mesenchymal cells, ECM has fine fibrillar type 3 and some type 1 collagen and ground substance is rich in
    • hyaluronic acid/ sulfated GAGs to draw in water to resist compression
  3. Brown fat
    brown color comes from rich vascularity and many mitochondria

    function: convert lipid into thermal energy to keep fetus warm

    Components: multiocular adipocytes, ECM has type 3 collagen fibers with little ground substance
  4. 3 types of cartilage
    flexible, avascular, aneural tissue that resists compression and provides framework for other tissues

    hyaline, elastic, and fibrocartilage

    the first 2 are surrounded by perichondrium
  5. cartilage components
    cells: chondrocytes

    ECM: type 2 collagen fibrils (doesn't form fibers), elastic fibers only produced in elastic cartilage

    Ground substance: highly specialized by proteoglycan named aggrecan that concentrates sulfated GAGs (keratin sulfate and chondoitin sulfate), increased water resists compression while allowing free diffusion
  6. Hyaline cartilage
    glassy, nonfibrous, translucent in appearance and surrounded by perichondrium

    location: conducting portions of resp. pathway and on articular surfaces of bones

    Cells: chondrocytes located in lacunas produce matrix that is first concentrated around cell as territorial matrix and spreads to become interterritorial matrix
  7. composition of perichondrium
    outer fibrous layer with fibroblasts blending with surrounding tissue

    inner chondrogenic layer that can produce more chondrocytes
  8. Cartilage growth
    appositional: cells in inner chondrogenic layer divide & add to outer cartilage to allow hyaline cartilage to grow at edges

    • interstitial growith: mitoses produce isogenous cell groups within cartilage matrix to allow hyaline cartilage to grow from
    • inside
  9. articular cartilage
    hyaline at bone surfaces of synovial jts promotes smooth sliding of jt surfaces and resists compression

    there is NO perichondrium along jt surfaces
  10. Elastic cartilage
    -has perichondrium, cells more tightly packed than in hyaline, has type 2 collagen & elastic fibers

    location: external ear, ext. auditory canal, auditory tubes, and epiglottis
  11. Fibrocartilage
    location: pubic symphisis, intervertebral discs, menisci of knee, temporomandibular and sternoclavicular jts

    composition: combo of dense irreg CT and chondrocytes with NO perichondrium, continuous with bone

    H/E stain: hyaline cartilage like cells in matrix of mixed fibers
  12. damage and ossification of hyaline cartiage
    damage is replaced by scarring with dense CT with collagen 1 fibers

    ossification happens with age (marrow seen where it shouldn't exist)
  13. osteoarthritis
    erosion of hyaline cartilage lining jt surfaces

    loss of aneural cartilage allows grinding of bones leading to pain
Card Set
CT part 3
developmental and structural CT part of first CT lecture