Myotendinous Junction PDF

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MTJ...

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Myotendinous Junction (objectives 7.6 and 7.7) The ends of muscle fibres join tendons at the Myotendinous Junction. Force generated by the muscle fibres is transmitted through this junction to the bone to produce movement. This region is the site of Mechanoreceptors (Golgi Tendon Organs) that signal muscle tension. Interestingly, some research suggests that the MTJ is a point of weakness, while others have shown no lesions at this point in muscle injuries. The MTJ has a complex structure where multiple deep folds (arrow heads below) of the muscle fibre membrane (called the sarcolemma) are embedded into the connective tissue of the tendon. The perimysium of the muscle becomes continuous with collagen fibres in the tendon. The tendons including the MTJ receive blood supply from 2 sources- blood vessels from the muscle at one end, and blood vessels from bone at the other. This leads to an area of hypovascularity (limited blood supply) in the middle of the tendon- this will impede healing following injury. The MTJ sends sensory information back to the brain regarding muscle length (muscle spindles), tension (Golgi tendon organs), and pain.

MTJ (visible as the black vertical line)

low power image of MTJ’s...