all-or-nothing principle

The all-or-nothing principle states that a nerve cell or muscle fiber either fully responds to a stimulus or not at all. If the stimulus is strong enough to reach a certain threshold, the entire response is triggered, such as firing an action potential. If it’s below that threshold, there’s no response at all. This ensures consistent and clear communication within the nervous system, preventing partial or weak signals that could cause confusion. In essence, the response is binary: on or off, allowing the body to function efficiently and reliably.