|all-or-none (ôl'ər-nŭn') Pronunciation Key
Characterized by either a complete response or by a total lack of response or effect, depending on the strength of the stimulus. Neurons have an all-or-none response to impulse transmission and cannot be partially stimulated.
|occurring completely or not occurring at all|
|the offspring of a zebra and a donkey.|
|a printed punctuation mark (‽), available only in some typefaces, designed to combine the question mark (?) and the exclamation point (!), indicating a mixture of query and interjection, as after a rhetorical question.|