A classification of reflex actions / by D. Fraser Harris.

  • Fraser-Harris, David Fraser, 1867-1937.
Date:
1894
Catalogue details

Licence: Public Domain Mark

Credit: A classification of reflex actions / by D. Fraser Harris. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

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    vascular tonus, then active (arterial) hyperaenria, due to inhi- bition of the centre, would be a negative excito-vascular reflex (vaso-inhibitory of authors), while pallor would be the positive excito- vascular reflex ('' vaso-constrictor ). If there be two centres, one for vaso-constriction, Vc, and one for vaso-dilatation, Vd., then, e.g., blushing from present emo- tion would be either: X + emotio-vascular reflex through ^ *L Vd., or \ — emotio-vascular reflex through Vc; and simi- larly, emotional blanching would be either : \ + emotio- <£ vascular reflex through Vc, or 3L— emotio-vascular reflex ct through Vd. A word as to psychico-metabolic reflexes. Of course, all vital action is metabolic, but one can distinguish a kind of reflex concerned, not with definite glands or vessels, but having its manifestations through a wide spatial distribution. We may, as before, have metabolism stimulated or de- pressed, and thus a + psychico-metabolic reflex might be more shortly named psychico-anabolic, while a — psychico- metabolic reflex would be a psychico-katabolic reflex. Thus, the hair turning white through emotion would be a negative emotio-metabolic reflex. The emotional state has acted reflexly on centres trophic to the nerves influencing the formation of pigment over a considerable area of skin. It would be. under the category ideo-metabolic that we would place those well-authenticated cases of hallucina- tions causing or curing disease. Thus there is much mystery and romance dispelled when instead of miraculous cure by faith-healing we write positive ideo-metabolic (systemic) reflex ! Of course, metabolic reflexes might exist in other systems than the dermal. A final word on reflexes. It will be very evident that expression of the emotions is largely reflex, while any imitation of an emotion—simulation of a particular expres- sion—is a different tbing psychologically ; it is voluntary to begin with. Moreover, • expression of many emotions is eminently under control: self-command does not so much consist in not experiencing certain emotions, as in bein<* habitually able to inhibit or control their manifestations.