Stromal connective tissues are found in the stroma; this tissue belongs to the group connective tissue proper. The function of connective tissue proper is to secure the
parenchymal tissue, including blood vessels and nerves of the stroma, and to construct organs and spread mechanical
tension to reduce localised stress. Stromal tissue is primarily made of
extracellular matrix containing connective tissue cells. Extracellular matrix is primarily composed of
ground substance - a porous, hydrated gel, made mainly from
proteoglycan aggregates - and connective tissue fibers. There are three types of fibers commonly found within the stroma:
collagen type I,
elastic, and
reticular (collagen type III) fibres.
Cells •
Wandering cells - cells that migrate into the tissue from blood stream in response to a variety of stimuli; for example, immune system blood cells causing inflammatory response. • Fixed cells - cells that are permanent inhabitants of the tissue. •
Fibroblast - produce and secrete the organic parts of the ground substance and extracellular fibers of the matrix.
Types •
Loose connective tissue - This type is mainly located under the
epithelial membranes and glandular epithelium, attaching the epithelia to other tissues. It supports the blood vessels and nerves supplied to the epithelia. Additionally, it serves as the main site of
inflammatory response within the body. • Dense irregular connective tissue - the function of this type is binding at a
high tensile strength between tissues to convert tension from one point. ==References==