CONNECTIVE TISSUE FIBERS Dr Iram Tassaduq

CONNECTIVE TISSUE FIBERS Formed by proteins Three types of fibers  Collagen  Elastic  Reticular Uneven distribution

COLLAGEN FIBERS Most abundant type of C.T. fibers May be collected together to form a bundle of greater size Straight or slightly wavy course of fibers Loosely or densely packed fibers Staining

TYPES OF COLLAGEN

RETICULAR FIBERS Rete is a latin word which means net 0.5—2 um in diameter Composed of type III collagen Provide supporting frame work Occurs as fine network around small blood vessels, muscle fibers, nerve fibers and lymphoid organs

Not distinguishable in ordinary H&E staining due to their thinness. o Can be visualized with PAS staining, seen as red strands by due to presence of carbohydrates Called argyrophilic fibers because of their high affinity for silver salts.

ELASTIC FIBERS Typically thinner than collagen fibers Arranged in branching pattern to form a three dimensional network Interwoven with collagen fibers Provide tissue with ability to respond to stretch and distension

ELASTIC FIBERS Composed of two structural components Elastin Fibrillin 1 Elastic property of elastin molecules is related to its unusual polypeptide backbone that causes random coiling Elastic material is a major extra cellular substance in vertebral ligaments, larynx & elastic arteries

TYPES OF INTERCELLULAR SUBSTANCE Amorphous Fibrous Glycosaminoglycans Glycoproteins Collagen Fibers Elastic Fibers Reticular fibers

GLYCOSAMINOGLYCANS Polysaccharides containing amino sugar Secretion products of C.T. cells especially fibroblasts Stain with basic dyes Exhibit metachromasia

GLYCOPROTEINS Proteins with one or more heterosaccharide chains containing hexosamine, galactose, & other sugars These include: Fibronectin Laminin Tenascin Osteopontin

TYPES OF CONNECTIVE TISSUE

MESENCHYMAL CONNECTIVE TISSUE o Mesenchyme forms the undifferentiated "filling" of the early embryo. o It consists of mesenchymal cells, which interconnect by slender cell processes. o Mesenchymal cells have stem cell properties, i.e. they are able give rise to other cell and tissues types.

MESENCHYME MESENCHYME

MUCOUS CONNECTIVE TISSUE o It contain a large amount of ground substance. o Found in the umbilical cord (Wharton's jelly) and in embryonic tissues.

MUCOUS CONNECTIVE TISSUE

LOOSE AREOLAR CONNECTIVE TISSUE Widely distributed Provide supporting framework Acts as embedding medium for blood vessels and nerves

LOOSE AREOLAR CONNECTIVE TISSUE

RETICULAR CONNECTIVE TISSUE Consist of reticular cells and fibers Cells are stellate shape Form stroma of liver,spleen and bone marrow

DENSE IRREGULAR CONNECTIVE TISSUE

DENSE REGULAR CONNECTIVE TISSUE

ADIPOSE TISSUE