
Dense irregular connective tissue has fibers that are not arranged in parallel bundles as in
dense regular connective tissue.
Dense irregular connective tissue consists of mostly collagen fibers. It has less
ground substance than
loose connective tissue.
Fibroblast
A fibroblast is a type of biological cell that synthesizes the extracellular matrix and collagen, produces the structural framework ( stroma) for animal tissues, and plays a critical role in wound healing. Fibroblasts are the most common cells of ...
s are the predominant cell type, scattered sparsely across the tissue.
Function
This type of connective tissue is found mostly in the
reticular layer (or deep layer) of the
dermis. It is also in the
sclera and in the deeper skin layers. Due to high portions of
collagenous fibers, dense irregular connective tissue provides strength, making the skin resistant to tearing by stretching forces from different directions.
Dense irregular connective tissue also makes up
submucosa of the digestive tract,
lymph node
A lymph node, or lymph gland, is a kidney-shaped organ of the lymphatic system and the adaptive immune system. A large number of lymph nodes are linked throughout the body by the lymphatic vessels. They are major sites of lymphocytes that inc ...
s, and some types of
fascia
A fascia (; plural fasciae or fascias; adjective fascial; from Latin: "band") is a band or sheet of connective tissue, primarily collagen, beneath the skin that attaches to, stabilizes, encloses, and separates muscles and other internal organ ...
.
Other examples include
periosteum and
perichondrium of bones, and the
tunica albuginea of testis. In the submucosa layer, the fiber bundles course in varying planes allowing the organ to resist excessive stretching and distension.
References
Tissues (biology)
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