Reflex

Origin

Latin reflexus, past participle of reflectere to reflect

• 16th Century

Definitions

• 1a archaic : reflected heat, light, or color

b : a mirrored image

c : a copy exact in essential or peculiar features

• 2a : an automatic and often inborn response to a stimulus that involves a nerve impulse passing inward from a receptor to a nerve center and thence outward to an effector (as a muscle or gland) without reaching the level of consciousness — compare habit

b : the process that culminates in a reflex and comprises reception, transmission, and reaction —called also reflex action

c plural : the power of acting or responding with adequate speed

d : a way of thinking or behaving

• 3: a linguistic element (as a word or sound) or system (as writing) that is derived from a prior and especially an older element or system <boat is the reflex of Old English bāt>

Description

A reflex action, also known as a reflex, is an involuntary and nearly instantaneous movement in response to a stimulus. In most contexts, in particular those involving humans, reflex actions are mediated via the reflex arc; this is not always true in other animals, nor does it apply to casual uses of the term 'reflex'.

• Reaction time

For a reflex, reaction time or latency is the time from the onset of a stimulus until the organism responds. In animals, reaction time to visual stimuli is typically 150 to 300 milliseconds.[1]