Biographies de neurologues
Nouvelle Iconographie de La Salpêtrière
 L'histoire des neurosciences à La Pitié et à La Salpêtrière J Poirier
The history of neurosciences at La Pitié and La Salpêtrière J Poirier 

mise à jour du
22 février 2010
july 17, 1897
The therapeutic aspects of talking, shouting, singing,
laughing, crying, sighing and yawning
Harry Campbell
Northwest London Hospital


It is difficult to describe accurately this act. A deep and prolonged inspiration is taken through the mouth and nose, the mouth being widely opened and the nares dilated. The opening of the mouth is effected by a strong tonic contraction of the depressors of the lower jaw and by the extension of the head and consequent elevation of the upper jaw.
At the same time the limbs and trunk are stretched. There is, in short, a widespread tonic contraction of the muscle system. This continues and indeed reaches its climax during the expiratory portion of the act, the month being kept open till towards the end of it. The expiratory blast is directed solely through the mouth owing to the elevation of the soft palate, and the vocal cords approximate, a characteristic sound being produced in the larynx, while there is a peculiar contraction of the muscles at the back of the throat the nature of which I do not understand.
There can be little doubt that one of the objects of yawning is the exercise of muscles which have been for a long time quiescent, and the acceleration of the blood and lymph flow which has in consequence of this quiescence become sluggish.
Hence its frequency after one has remained for some time in the same position -e.g., when waking in the morning. Cooperating with this cause is sleepiness and the shallow breathing which it entails. This factor, as well as muscle-quiescence, is apt to attend the sense of boredom which one experiences in listening to a dull a sermon.
Hence it is that the bored individual is apt to yawn. As in the case of sighing, the deep breath which accompanies the act of yawning compensates for the shallow breathing which is so apt to excite it. I am unable to offer any explanation of the yawning-or, rather, gaping-which is induced by exhaustion from want of food. This mere gaping is, however, quite distinct from yawning, which is a much more complex phenomenon. Allied to yawning is a modification of the breathing which is apt to occur during sleep.
A deep breath is taken more or less suddenly, and this is followed by a long drawn out expiration with probbly closed glottis and a gronning sound.This kind of breathing has certainly some physiological import, but what it is I cannot say.
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