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In biology, a reflex, or reflex action, is an involuntary, unplanned sequence or action [1] and nearly instantaneous response to a stimulus. [2] [3] The simplest reflex is initiated by a stimulus, which activates an afferent nerve. The signal is then passed to a response neuron, which generates a response.
The PNS includes motor neurons, mediating voluntary movement; the autonomic nervous system, comprising the sympathetic nervous system and the parasympathetic nervous system and regulating involuntary functions; and the enteric nervous system, a semi-independent part of the nervous system whose function is to control the gastrointestinal system.
Motor control is the regulation of movements in organisms that possess a nervous system.Motor control includes conscious voluntary movements, subconscious muscle memory and involuntary reflexes, [1] as well as instinctual taxes.
Knee jerk or patellar reflex — a kick caused by striking the patellar tendon with a tendon hammer just below the patella, stimulating the L4 and L3 reflex arcs. Moro reflex , a primitive reflex — only in all infants up to 4 or 5 months of age: a sudden symmetric spreading of the arms, then unspreading and crying, caused by an unexpected ...
In anatomy, the extrapyramidal system is a part of the motor system network causing involuntary actions. [1] The system is called extrapyramidal to distinguish it from the tracts of the motor cortex that reach their targets by traveling through the pyramids of the medulla.
One of the most widespread feedback systems in limb postural control is the resistance reflex in arthropods and stretch reflex in vertebrates. [ 7 ] [ 8 ] These feedback loops consist of sensory neurons that detect external perturbations and activate motor neurons that produce movements that counter the imposed movement.
Autonomic functions include control of respiration, cardiac regulation (the cardiac control center), vasomotor activity (the vasomotor center), and certain reflex actions such as coughing, sneezing, swallowing and vomiting. Those are then subdivided into other areas and are also linked to autonomic subsystems and the peripheral nervous system.
A common example of reciprocal innervation, is the effect of the nociceptive (or nocifensive) reflex, or defensive response to pain, otherwise commonly known as the withdrawal reflex; a type of involuntary action of the body to remove the body part from the vicinity of an offending object by contracting the appropriate muscles (usually flexor ...