13 Facts About Eccentric contraction

Muscle Eccentric contraction is the activation of tension-generating sites within muscle cells.

The termination of muscle Eccentric contraction is followed by muscle relaxation, which is a return of the muscle fibers to their low tension-generating state.

In contrast, a muscle Eccentric contraction is isotonic if muscle tension remains the same throughout the Eccentric contraction.

The Eccentric contraction produced can be described as a twitch, summation, or tetanus, depending on the frequency of action potentials.

Excitation–Eccentric contraction coupling is the process by which a muscular action potential in the muscle fiber causes the myofibrils to contract.

In skeletal muscle, excitation–Eccentric contraction coupling relies on a direct coupling between key proteins, the sarcoplasmic reticulum calcium release channel and voltage-gated L-type calcium channels .

Excitation–Eccentric contraction coupling occurs when depolarization of skeletal muscle cell results in a muscle action potential, which spreads across the cell surface and into the muscle fiber's network of T-tubules, thereby depolarizing the inner portion of the muscle fiber.

Physiologically, this Eccentric contraction is not uniform across the sarcomere; the central position of the thick filaments becomes unstable and can shift during Eccentric contraction but this is countered by the actions of the elastic myofilament of titin.

Finally, if the frequency of muscle action potentials increases such that the muscle Eccentric contraction reaches its peak force and plateaus at this level, then the Eccentric contraction is a tetanus.

In both skeletal and cardiac muscle excitation-Eccentric contraction coupling, depolarization conduction and Ca release processes occur.

Excitation-Eccentric contraction coupling in cardiac muscle cells occurs when an action potential is initiated by pacemaker cells in the sinoatrial node or Atrioventricular node and conducted to all cells in the heart via gap junctions.

In 1952, the term excitation–Eccentric contraction coupling was coined to describe the physiological process of converting an electrical stimulus to a mechanical response.

Mechanism for muscle Eccentric contraction evaded scientists for years and requires continued research and updating.