RESPIRATION 203 



elevate the ribs may be thrown into contraction, as well as 

 other muscles which give these fixed points to act from. 

 During a paroxysm of asthma, for example, the patient may 

 grasp the back of a chair with his hands, so as to fix the 

 arms and shoulders and allow the pectoral and serratus 

 magnus to raise the ribs. Similarly in forced expiration 

 all the muscles are used which can depress the ribs, or 

 increase the intra-abdominal pressure and push up the 

 diaphragm. 



Certain accessory phenomena (movements and sounds) are 

 associated with the proper movements of respiration. The 

 larynx rises in expiration, and sinks in inspiration. The 

 glottis (and particularly its posterior portion, the glottis 

 respiratoria) is widened during deep inspiration and 

 narrowed during deep expiration. The same is the case 

 with the nostrils, and, indeed, in some persons the alae nasi 

 move even in ordinary breathing. 



As regards the respiratory sounds, all that is necessary to 

 be said here is that when we listen over the greater portion 

 of the lungs with the ear, or, much better, with a stetho- 

 scope, a soft breezy murmur, that has been compared to the 

 rustling of the wind through distant trees, is heard. This 

 has been called the vesicular murmur. It is only heard in 

 health during inspiration and the very beginning of expira- 

 tion, and is louder in children than in adults. It is not 

 definitely settled whether this sound arises at the glottis 

 and is modified by transmission through the pulmonary 

 tissue, or whether it arises somewhere in the terminal 

 bronchi, the infundibula or the alveoli. Both views may be 

 supported by certain arguments, and to both some objec- 

 tions may be raised. But it is generally admitted, and this 

 is of great importance in practical medicine, that when 

 the normal sound is heard over any portion of the lung 

 tissue, it may be inferred that this portion is being properly 

 distended, and that air is freely entering its alveoli. Around 

 the larger bronchi and the trachea a blowing sound is heard. 

 In health this is not recognised over the greater portion of 

 the lung, but in certain diseases in which the alveoli are 

 filled up with exudation, this bronchial or tubular breathing 



