Sometimes called FIBROUS TISSUE, it is one of the most abundant tissues in the body, holding together the body's many different structures. Connective tissue comprises a matrix of substances called mucopolysaccharides in which are embedded various specialist tissues and cells. These include elastic (yellow), collagenous (white) and reticular fibres as well as MACROPHAGES and MAST CELLS. Assembled in differing proportions, this provides structures with varying functions: bone, cartilage, tendons, ligaments and fatty and elastic tissues. Collagenous connective tissue binds the muscles together and provides the substance of skin. It is also laid down in wound repair, forming the scar tissue. Contracting with time, connective tissue becomes denser, causing the puckering that is typical in serious wounds or burns. (See ADHESION; SCAR; WOUNDS.)