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
 12 novembre 2006
The Lancet
Janv 21; 1905
p 174
"Ne quid nimis"


Yawning is a complex, automatic, physiological phenomenon whereby the lungs are fully expanded, the heart is to greater activity, and, probably, the blood is charged more fully in oxygen. It commences with an involontary spasm of certain muscles of mastication and deglutition; its termination is akin to the process of sighing, and, like the manifestation of deep breathing, it reinforces respiration.
At night, when respiration is slckening, or in the morning, when it has not recovered its waking rhythm, yawning is accompanied sometimes by the "stretching" of successive groups of muscles the blood vessels of which have probably been compressed by the previous assumption of a constrained position; the local circulation is thus assisted and stimulated.
The preacher, the novelist,, and the artist emply the mechanism of yawning as an indication of ennui, of lack of interest, or of wearied attention, whether real or feigned. To the clinician it should be signifiant od an attack of asystole and consequent temporary anaemia of the brain, especially of the corpus stritum. In diseases where "air hunger" is a frequent symtom yawning is also exhibited.
It is met with diabetes, in fatty and fibroid changes in the walls of the heart, in pericarditis, and in the pathological conditions which lead to the faulty filling of the aorta. Yawning suggests the proximity of a fatal ending after copious heamorrhage and in pernicious anaemia and Addison's disease. Dr Hughlings Jackson recorded a remarkable demonstration shortly after the introduction of the use of the ophtalmoscope. He was surveying the fundus of an eye when suddendly the field became pale. This pallor was due obviously to a contraction of the retinal blood vessels. He thereupon stood back, expecting something to happen, and in fact the patient immediately yawned. The observer had seen, in part, a spasm of the cerebral arteries.
Yawning the Lancet 1905
Yawning Lancet 1952
Yawning: its physiology and psychology Lancet 1921