Abstract
Connective tissue, found abundantly throughout the body, is a heterogeneous mixture of cells and fibers embedded in an amorphous matrix known as mesenchymal ground substance. It functions, in part, to support and compartmentalize the various tissues and organs of the body. The proportion of cells and noncellular components of connective tissue varies in quantity, composition, and arrangement, apparently to meet the functional requirements of location and specificity in the body. | The chemical properties of connective tissue are, in general, related to those chemical and structural properties of individual components present therein. Of particular interest are the characteristics and features of the amorphous ground substance. This intercellular matrix is known to envelop all of the formed elements comprising connective tissue proper and serves as the medium through which nutrients and waste products can be transferred from the cells to the blood stream. The structure of ground substance, depending upon its location, may vary from a sol-like to a gel-like state in order to mediate physiological processes. Ground substance serves as a water and ion reservoir for the maintenance of cellular concentrations. It acts to maintain spatial and functional relationships of the cellular and fibrillar components of a tissue and functions to support and protect the organs of the body against various diseases. Moreover, it suffices as the medium into which the connective tissue cells secrete the forms of soluble collagen which eventually aggregate to form important structural fibers of connective tissue. The composition of ground substance may be altered by such inflammatory conditions as scurvy, gingivitis, and periodontitis. Though the matrix may appear histologically homogeneous or finely granular, extensive investigation, such as those summarized by Jeanloz and Balazs, demonstrate that it is composed of a mixture of hexosamine containing macromolecules including hyaluronic acid, proteinpolysaccharides containing the hondroitin sulfates A, B, and C, the keratan sulfates, and in some cases heparin and heparan sulfate. Chemically, the acid mucopolysaccharides are repeating polymers of a hexosamine and uronic acid, although the keratan sulfates are known to contain galactose in place of the uronic acid. Furthermore, a less well defined group of macromolecules, called glycoproteins, can be extracted from connective tissue.