Tendon and degeneration or weakening of the tendons, which may eventually lead to tendon rupture. Tendinopathies can be caused by a number of factors relating to the tendon extracellular matrix (ECM), and their classification has been difficult because their symptoms and histopathology often are similar. The first category of tendinopathy is paratenonitis, which refers to inflammation of the paratenon, or paratendinous sheet located between the tendon and its sheath. Tendinosis refers to non-inflammatory injury to the tendon at the cellular level. The degradation is caused by damage to collagen, cells, and the vascular components of the tendon, and is known to
Achilles tendon expression "Achilles' heel") and he was eventually killed by a poison dart to the heel. The name thus also refers to the particularly disabling and painful effect of an injury to this tendon. The first closed rupture was described by Ambroise Pare in the sixteenth century. The Achilles tendon is also known as the "tendo calcaneus" (). Because eponyms (names relating to people) have no relationship to the subject matter, most anatomical eponyms also have scientifically descriptive terms. The term calcaneal comes from the Latin "calcaneum", meaning heel. Achilles tendon The Achilles tendon or heel cord, also known as the