tonic reflex(redirected from Gordon symptom)
the occurrence of an appreciable interval after the production of a reflex before relaxation, for example, the leg remains up for a time after a knee jerk.
Synonym(s): Gordon symptom
Gordon,Alfred, U.S. neurologist, 1874-1953.
Gordon reflex - dorsal flexion of the great toe produced by firm lateral pressure on the calf muscles. Synonym(s): paradoxical flexor reflex
Gordon sign - a sign of organic hemiplegia. Synonym(s): finger phenomenon
Gordon symptom - the occurrence of an appreciable interval after the production of a reflex before relaxation. Synonym(s): tonic reflex
a reflected involuntary action or movement; the sum total of any particular automatic response mediated by the nervous system.
A reflex is built into the nervous system and does not need the intervention of conscious thought to take effect.
For reflexes used in clinical examination of a patient see under individual titles including anal, blink, corneal, conjunctival, crossed extensor, extensor thrust, eyelid, gastrocnemius, hopping, palpebral, panniculus, patellar, perineal, placing, pupillary, withdrawal.
the coordinated changes that occur when the eye adapts itself for near vision; they are constriction of the pupil, convergence of the eyes and increased convexity of the lens.
an involuntary response to a stimulus conveyed to the nervous system and reflected to the periphery (see also reflex).
bradycardia occurring as a reflex initiated by severe atrial or ventricular stretch.
a series of reflexes, each serving as a stimulus to the next, making a complete activity.
one requiring no feedback from the forebrain.
see conditioned response.
cutaneous trunci reflex
see panniculus reflex.
a test of the retina, optic nerve, and central retinal pathways. Shining a bright light into the eye should cause squinting.
see detrusor-urethral dyssynergia.
increase in ileal motility and opening of the ileocecal valve when food enters the empty stomach.
see pupillary light reflex.
reflexes initiated by painful stimuli.
see swallowing reflex.
relaxation of the anal sphincter which occurs with distention of the rectum and during defecation.
movements of progression elicited when the animal is held upright and inclined forward with the feet touching a flat surface.
reflex contraction of a muscle in response to passive longitudinal stretching.
any withdrawal reflex elicited by noxious or tactile stimulation of the skin, cornea or mucous membrane, including the corneal and pharyngeal reflexes.
tapetal reflection of light.
a method of testing the patency of reflex arc. The tendon is stretched sharply by tapping it close to its insertion. A positive reaction is a sharp contraction of the muscle of which the tendon is part. The patellar reflex is the best known of these reflexes. Absence indicates a defect in the reflex arc, an exaggerated response suggests an upper motor neuron lesion. Called also myotactic reflex.
see tonic neck response.
triceps surae reflex
a test of the ophthalmic and mandibular divisions of the trigeminal nerve, and the abducens nerve. Light touching of the cornea should result in retraction of the globe and protrusion of the nictitating membrane.
spinal reflexes can provide support and uncoordinated use of the hindlegs that resembles walking, in dogs with transection of the spinal cord between T13 and L4.
pinching the pinna elicits a twitch of the whiskers in cats; used in assessment of depth of anesthesia.