Illustration of the anatomy of a tendon and its structure. At the top, tendon structure: epitenon, tertiary fibre bundle bound by endotenon, tertiary fibre bundle, secondary fibre bundle, primary fibre bundle, collagen fibre bound by tenocytes (green), fibril and tropocollagen. At the bottom, left to right: bone structure (beige), tendon (white), synovial sheath (green, cut on the right), fibrous white sheath which surrounds the synovial sheath (cut here as it usually maintains the tendon in contact with the bone structure), muscle (pink).