Open AccessMyotatic reflexes in sympathectomised muscle
Author(s) -
Gilbert Phillips
Publication year - 1932
Publication title -
proceedings of the royal society of london. series b, containing papers of a biological character
Language(s) - English
Resource type - Journals
eISSN - 2053-9185
pISSN - 0950-1193
DOI - 10.1098/rspb.1932.0036
Subject(s) - reflex , efferent , decerebrate state , tonic (physiology) , proprioception , anatomy , ankle jerk reflex , medicine , afferent , neuroscience , physical medicine and rehabilitation , psychology , anesthesia , stimulation , electric stimulation
As a result of their experiments on normal, spinal and decerebrate animals Hunter and Royle (1924) concluded that the post-ganglionic fibres of the sympathetic nervous system constituted the efferent limb of the reflex arc subserving postural contraction in skeletal muscle. In a recent article (1931) the present author described a series of experiments on decerebrate cats in which Royle’s observation of diminished resistance to passive flexion in a sympathectomised “decerebrate” extensor muscle was confirmed, but the hypothesis that this was due to a “tonic” nervous influence of sympathetic axones on skeletal muscle fibres was denied. This denial was based on the fact that postural contraction was modified but not abolished by sympathectomy, and that the operation actually enhanced such proprioceptive reflexes as the shortening reaction and the crossed extensor reflex of Philippson (1905). Finally it was suggested that the diminished resistance of the extended “decerebrate” limb to passive flexion and the enhancement of those proprioceptive reflexes which, could be elicited by stretching the sympathectomised muscle were produced by a disturbance of the excitability of its proprioceptive end-organs. Denny-Brown (1928), after studying postural reflexes, has stated that the sympathetic nervous system is not essential to the stretch reflex, but he further stated that he was unable to discover any effect on general posture by excision of the sympathetic.