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
Mixed connective tissue disease Mixed connective tissue disease Mixed connective tissue disease (also known as Sharp's syndrome), commonly abbreviated as MCTD, is an autoimmune disease characterized by the presence of high blood levels of a specific autoantibody, now called anti-U1 ribonucleoprotein (RNP). The idea behind the "mixed" disease is that this specific autoantibody is also present in other autoimmune diseases such as systemic lupus erythematosus, polymyositis, scleroderma, etc. It was characterized in 1972, and the term was introduced by Leroy in 1980. It is sometimes said to be the same as undifferentiated connective tissue disease, but other experts specifically reject this idea because undifferentiated