Dense irregular connective tissue stretching forces from different directions. Dense irregular connective tissue also makes up submucosa of the digestive tract, fibrous capsules of joints and lymph nodes, and some types of fascia. 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. Dense irregular connective tissue 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
Interstitium Interstitium The interstitium is a contiguous fluid-filled space existing between a structural barrier, such as a cell wall or the skin, and internal structures, such as organs, including muscles and the circulatory system. The fluid in this space is called "interstitial fluid", comprises water and solutes, and drains into the lymph system. The interstitial compartment is composed of connective and supporting tissues within the body – called the extracellular matrix – that are situated outside the blood and lymphatic vessels and the parenchyma of organs. The non-fluid parts of the interstitium are predominantly collagen types I, III, and V, elastin,