Muscles, skeletal, smooth, cardiac Healthcare professionals and scientists have carefully prepared this ALtruis Biomedical Network-affiliated site, intended for informational purposes only . An action potential is an electrical change across a cell membrane due to changes in the conduction of ions across the membrane.
Nervous tissue is also an excitable tissue.
Muscle cells contain a contractile mechanism that is activated by the action potential. Contraction by a whole muscle Isometric versus Isotonic Isotonic contractions are those when the tension on a muscle remains constant but the muscle shortens as in lifting a static amount of weight. Isometric muscle contractions occur when the muscle doesn't shorten as, for example when pushing against an immovable object like a wall. Isometric contraction differs from isotonic in that the myofibrils don't slide over each other much as force is developed. Sliding does occur in isotonic contractions and external work is performed.