noun, plural: reflexes
(physiology) An innate, immediate involuntary action to a stimulus without prior conscious thought
In physiology, a reflex is a response or a reaction to a stimulus. The response is innate and need not to be learned. It is an involuntary reaction of the body to a stimulus. It often follows a pathway that begins at the sensory neuron stimulated by a stimulus and then sending signals to a nerve center, which in turn, sends signals to the effector cells to carry out an action accordingly. A reflex arc is the neural pathway that controls reflex reactions. The body reacts to a stimulus as an automatic response before the impulse reaches the brain. This allows quick response that is essential especially during events that pose threat to the safety of an individual.
Examples of human reflexes are stretch reflexes (e.g. biceps reflex, brachioradialis reflex, extensor digitorum reflex, triceps reflex, patellar reflex, and ankle jerk reflex), tendon reflex, primitive reflexes (e.g. moro reflex, rooting reflex, sucking reflex, palmomental reflex), and so on.