Fascia

A fascia ( /ˈfæʃiə/; plural fasciae /ˈfæʃɨ.aɪ/; adjective fascial; from Latin: "band") is a layer of fibrous tissue. A fascia is a structure of connective tissue that surrounds muscles, groups of muscles, blood vessels, and nerves, binding some structures together, while permitting others to slide smoothly over each other. Various kinds of fascia may be distinguished. They are classified according to their distinct layers, their functions and their anatomical location: superficial fascia, deep (or muscle) fascia, and visceral (or parietal) fascia.

Like ligaments, aponeuroses, and tendons, fasciae are dense regular connective tissues, containing closely packed bundles of collagen fibers oriented in a wavy pattern parallel to the direction of pull. Fasciae are consequently flexible structures able to resist great unidirectional tension forces until the wavy pattern of fibers has been straightened out by the pulling force. These collagen fibers are produced by the fibroblasts located within the fascia.

Fasciae are similar to ligaments and tendons as they are all made of collagen except that ligaments join one bone to another bone, tendons join muscle to bone and fasciae surround muscles or other structures.