excitation

(ek-si-ta's hun). Stimulation, increasing the rapidity or intensity of the physical or mental proce es, law of c, a motor nerve replies, by contraction of its muscle, not to the absolute value, but to the alteration of value from moment to moment, of the electric current. law of polar e., a given segment of a nerve is irritated by the development of cat electrotonus and the disappearance of an electrotonus, but the reverse does not hold.