Soft tissue Soft tissue In anatomy, soft tissue includes the tissues that connect, support, or surround other structures and organs of the body, not being hard tissue such as bone. Soft tissue includes tendons, ligaments, fascia, skin, fibrous tissues, fat, and synovial membranes (which are connective tissue), and muscles, nerves and blood vessels (which are not connective tissue). It is sometimes defined by what it is not. Soft tissue has been defined as "nonepithelial, extraskeletal mesenchyme exclusive of the reticuloendothelial system and glia". The characteristic substances inside the extracellular matrix of this kind of tissue are the collagen, elastin and ground substance.
Collagen, type XVII, alpha 1 of laminin 5 into the matrix requires collagen XVII. Mutations in the human collagen XVII gene, , lead to the absence or structural alterations and mutations of collagen XVII. The functional consequences include diminished epidermal adhesion and skin blistering in response to minimal shearing forces. The disorder caused by biallelic COL17A1 mutations and is called junctional epidermolysis bullosa, an autosomal recessive skin disease with variable clinical phenotypes. Morphological characteristics of junctional epidermolysis bullosa are rudimentary hemidesmosomes and subepidermal tissue separation. Clinical hallmarks, in addition to blisters and erosions of the skin and mucous membranes, include nail dystrophy, loss of hair,