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
23 mars 2008
Mac Millan
Human Physiology
Luigi Luciani


XIV. The rhythmical respiratory movements suffer various moifications, in abnormal or unusual conditions, or to satisfy various temporary needs or occurrences, or, lastly, as the motor expression of special sentiments of pleasure or pain, fatigue, ennui, sleep, etc. The principal forms may be briefly summarised as an pendix to the mechanics of respiration.
When there are mechanical impediments to the thoracic or abdominal respiratory movements, e.g. plaster bandages applied to the chest or epigastrium, the activity of the diaphragm or the elevator muscles to the ribs, respectively, is exaggerated, and the rhythm becomes deeper and slower.
When the respiratory movements cause or increase pains in the thorax or abdomen, respiratory rhythm becomes more frequent and superficial.
Where there is morbid stenosis of the air-passages, the respirations become deeper and less frequent. In pneumonia or pleurisy, with effusions into the pleural cavity, both frequency and depth of rhythm are accentuated.
Both secretions and exudations along the air-passages, as also foreign bodies, solid, liquid, or gaseous, which penetrate them, readily produce a reflex cough. This consists in loud, expiratory efforts, which produce enforced opening of the previously closed glottis, and by means of which the irritant is expelled. Coughing may be voluntary, and even when the cough is involuntary, it can be moderated and even inhibited by the will.
The presence of mucus, of foreign bodies, or of substances which irritate the nasal mucosa, may give rise to sneezing, which consists in one or more sudden and noisy expirations through the nasal passages, preceded by profound inspirations. In sneezing, the glottis is always open, the posterior nares are constricted by the rise of the soft palate, the mouth is seldom open. It is invariably a reflex act, which can only be imitated imperfectly by the will; it can, however, be voluntarily modified. The use of snuff makes the nasal mucosa insensitive after a few days, and suppresses sneezing.
Noisy crying, such as is frequent in childhood and youth, as the expression of physical and moral pain, consists in short and spasmodic inspirations, followed by prolonged expirations, with constricted glottis, relaxed muscles of face and jaw, simultaneous flow of tears and emission of high, inarticulate, laryngeal sounds. Sometimes it is associated with sobbing, which consists in repeated contractions of the diaphragm, producing sudden closure of the vocal cords, with a characteristic and quite involuntary sound.
Noisy laughter, the expression of sudden pleasant and unexpected sensations, or of hysteria, consists in short and rapidly succeeding expiratory efforts through the vocal cords, which are now brought close, and now separated, producing high, clear, and inarticulate tones, with trembling of the soft palate. The mouth is generally open, and the facial muscles contract in a characteristic manner. Laughter can easily be imitated at will, and to a certain extent can be voluntarily suppressed or moderated.
Yawning, the external expression of ennui, drowsiness, hunger, consists in a long, deep inspiration, in which many of the accessory inspiratory muscles participate, while the mouth, fauces, and glottis open convulsively. Inspiration is followed by a shorter expiration, and the two acts are accompanied by prolonged characteristic sounds, and by a general stretching of the arms and trunk. It is always an involuntary modification of breathing, easily imitated by the will.