Connective tissue disease Connective tissue disease A connective tissue disease is any disease that has the connective tissues of the body as a target of pathology. Connective tissue is any type of biological tissue with an extensive extracellular matrix that supports, binds together, and protects organs. These tissues form a framework, or matrix, for the body, and are composed of two major structural protein molecules: collagen and elastin. There are many different types of collagen protein in each of the body's tissues. Elastin has the capability of stretching and returning to its original length—like a spring or rubber band. Elastin is the major
Keratin about 10 µm across, with cores and coating, and may be arranged in up to 10 layers, also in plaques of variable shape. Adult hornets also use silk as a glue, as do spiders. Some infectious fungi, such as those that cause athlete's foot and ringworm (i.e. the dermatophytes), or "Batrachochytrium dendrobatidis" (Chytrid fungus), feed on keratin. Diseases caused by mutations in the keratin genes include: Keratin expression is helpful in determining epithelial origin in anaplastic cancers. Tumors that express keratin include carcinomas, thymomas, sarcomas and trophoblastic neoplasms. Furthermore, the precise expression pattern of keratin subtypes allows prediction of the