CONNECTIVE TISSUE. Origin of connective tissue cells

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Text of CONNECTIVE TISSUE. Origin of connective tissue cells

  • CONNECTIVE TISSUE

  • Origin of connective tissue cells

  • LOOSE CONNECTIVE TISSUECharacterized by loosely arranged fibers and an abundance of cellsThe primary location is :beneath those epithelia that cover the body surfaces and line the internal surfaces of the bodyIn association with the epithelium of glandssurrounds the small vessels

  • Loose connective tissue (scheme)

  • Light micrograph of loose C.T.

  • Connective tissue cells can be categorized as fixed and wandering

    Fixed cell populationWandering cell populationFibroblasts- LymphocytesMyofibroblasts- Plasma cellsMacrophages- NeutrophilsMast cells - EosinophilsAdipose cells- BasophilsReticular cells - MonocytesUndifferentiated stem cells

  • E.M. of fibroblast portion with the adjusting collagen fibers

  • E.M. of a macrophage surrounded with collagen fibers

  • L.M. of macrophages in liver (von Kupffer cells)

  • Specific names of different location macrophages (macrophage system)Monocytes (blood)Macrophages-histiocytes (connective tissue)Dust cells (lung alveoli)Kupffer cells (liver)Langerhans cells (skin)Hofbauer cells (placenta)Osteoclasts (bone)Microglia (brain)Dendritic cells (lymphoid organs)Microfold (M) cells (intestine)

  • E.M. of a mast cell

  • Physiologically active substances secreted by mast cells

  • E.M. of adipocytes on different stages of maturation

  • Plasma cell schematic representation

  • NON-CELLULAR COMPONENTS OF CONNECTIVE TISSUE FibersCollagen fibers forms the most abundant fibers of connective tissue Reticular fibers provide a supporting framework for the cellular constituents of lymphoid organs mostlyElastic fibers provide tissues with the ability to respond to stretch and distensionGround substance consists largely of highly hydrated proteoglycans, of hyaluronic acid, and GAG (chodroitin-sulphate, heparan-sulphate, dermatan-sulphate, keratan-sulphate)

  • CLASSIFICATION OF CONNECTIVE TISSUES

  • DENSE CONNECTIVE TISSUEDENSE IRREGULAR CONNECTIVE TISSUE is characterized by an abundance of fibers and few cells. It forms the reticular or deep layer of the dermis

    DENSE REGULAR CONNECTIVE TISSUE is characterized by ordered and densely packed arrays of fibers and cells. It is the main functional component of tendons, ligaments, aponevroses

  • L.M. of a tendon, cross section