What is a tendon?

• A. Flexible, inelastic cord of strong fibrous collagen tissue attaching a muscle to bone
• B. Tough fibrous band of tissue connecting the articular extremities of bones or supporting an organ in place
• C. A fluid-filled sac that reduces friction in joints
• D. A connective tissue that surrounds muscle fibers

Answer: (A)

Tendons are the structures that transmit the force generated by muscle to the bone, enabling movement. They are dense, fibrous cords made mainly of type I collagen, aligned in parallel to handle high pulling forces. This composition gives them great tensile strength while keeping them relatively inelastic, which is ideal for efficiently converting muscle contraction into bone movement. Tendons typically connect the muscle belly to bone across joints, acting like cables that pull on bones when a muscle contracts.

This explanation helps distinguish tendons from other structures: ligaments connect bone to bone to stabilize joints; bursae are fluid-filled sacs that reduce friction; and the connective tissue around muscle fibers (like fascia or the endomysium/perimysium) surrounds individual muscles or groups of fibers, not the muscle-to-bone connection.