The tissue by which a muscle attaches to bone. A tendon is somewhat flexible, but fibrous and tough. When a tendon becomes inflamed, the condition is referred to as tendinitis or tendonitis. Inflamed tendons are at risk for rupture. Tendons are like ligaments in being tough, flexible cords. But tendons differ from ligaments in that tendons extend from muscle to bone whereas ligaments go from bone to bone as at a joint. Despite their tough fibrous nature, tendons and ligaments are both considered "soft tissue," that is soft as compared to cartilage or bone. The term "tendon" comes from the Latin "tendere" and the Greek "teinein." Both mean "to stretch." The Achilles tendon is a celebrated example of a tendon.
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A nondistensible fibrous cord or band of variable length that is the part of the muscle that connects the fleshy (contractile) part of muscle with its bony attachment or other structure; it may unite with the fleshy part of the muscle at its extremity or may run along the side or in the center of the fleshy part for a longer or shorter distance, receiving the muscular fibers along its border; when determining the length of a muscle, the t. length is included as well as the fleshy part; it consists of fascicles of very densely arranged, almost parallel collagenous fibers, rows of elongated fibrocytes, and a minimum of ground substance. SYN: tendo [TA], sinew. [L. tendo]
- Achilles t. SYN: calcaneal t..
- calcaneal t. [TA] the thick t. of insertion of the triceps surae (gastrocnemius and soleus) into the tuberosity of the calcaneus. SYN: tendo calcaneus [TA], Achilles t., chorda magna, heel t., tendo Achillis.
- central t. of diaphragm [TA] a three-lobed fibrous sheet comprising the center of the diaphragm; superiorly it is fused with the fibrous pericardium that provides attachment (insertion) for the moving end of the muscle fibers. SYN: centrum tendineum diaphragmatis [TA], trefoil t..
- central t. of perineum [TA] the fibromuscular mass between the anal canal and the urogenital diaphragm in the median plane onto which several perineal muscles insert (bulbospongiosus, external anal sphincter, superficial, and deep transverse perineal muscles); midline episiotomies extend into this structure. SYN: centrum tendineum perinei [TA], perineal body, Savage perineal body.
- conjoined t. SYN: inguinal falx.
- conjoint t. inguinal falx. SEE ALSO: aponeurosis of internal oblique muscle.
- coronary t. SYN: (right and left) fibrous rings of heart, under ring.
- cricoesophageal t. [TA] longitudinal fiber of the esophagus that attaches to the posterior aspect of the cricoid cartilage of the larynx. SYN: tendo cricoesophageus [TA], Gillette suspensory ligament, suspensory ligament of esophagus.
- heel t. SYN: calcaneal t..
- Todaro t. an inconstant tendinous structure that extends from the right fibrous trigone of the heart toward the valve of the inferior vena cava.
- trefoil t. SYN: central t. of diaphragm.
- Zinn t. SYN: common tendinous ring of extraocular muscles.

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ten·don 'ten-dən n a tough cord or band of dense white fibrous connective tissue that unites a muscle with some other part, transmits the force which the muscle exerts, and is continuous with the connective-tissue epimysium and perimysium of the muscle and when inserted into a bone with the periosteum of the bone

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a tough whitish cord, consisting of numerous parallel bundles of collagen fibres, that serves to attach a muscle to a bone. Tendons are inelastic but flexible; they assist in concentrating the pull of the muscle on a small area of bone. Some tendons are surrounded by tendon sheaths - these are tubular double-layered sacs lined with synovial membrane and containing synovial fluid. Tendon sheaths enclose the flexor tendons at the wrist and ankle, where they minimize friction and facilitate movement. See also aponeurosis.
tendinous adj.

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ten·don (tenґdən) [L. tendo; Gr. tenōn] a fibrous cord of connective tissue by which a muscle is attached; see tendo. Tendons are usually named after the muscle to which they attach.

Medical dictionary. 2011.