actin and myosin

6.1 actin and myosin

6.2 remove calcium which requires ATP, troponin-tropomyosin shift back to original position preventing binding of actin and myosin, phosphate binds to  myosin to detach  from actin

6.3 summation – accumulation of effects, especially those of muscular or neural activity
recruitment – increasing the tone (or force) of a muscle by activating more motor units
tetanus – in a muscle a sustained maximal muscle contraction resulting from high-frequency stimulation