A cell theory.
Since cells are the basic unit of structure in all organisms and also the basic unit of reproduction.
A muscle fiber will respond to a stimulus when that stimulus reaches the threshold level. These local classified potentials which are mainly related with external stimuli extent the axon preliminary segment and construct up to they manage to extent the threshold value. The bigger the stimulus the larger the depolarization or try to reach threshold.
<span>Membrane structure and function: The plasma membrane, also known as the cell surface membrane or plasma-lemma, is the boundary of the cell. It regulates the movement of materials into and out of the cell and facilitates electrical signaling.</span>