20 AFFECTIONS OF THE LARYNX. 



clutches at its throat, pulls at its tongue, as if to remove the obstacle to 

 its breathing. The face is distorted and bedewed with sweat The 

 look of a child sick of croup is, above all things, sad and piteous. 



The circumstance, that children often die of croup, who, during life, 

 evinced signs of the greatest dyspnoea, but in whom, after death, neithei 

 pseudo-membrane nor considerable swelling, either of mucous membrane 

 or of the submucous tissue, could be discovered, has given rise to the 

 impression that, in these cases, spasmodic contraction of the laryngeal 

 muscles has constricted the glottis. This view is contradictory to patho- 

 logical and physiological fact. 



In all severe inflammation of mucous or serous membranes, we find 

 not only the submucous and subserous cellular tissues, but also the 

 muscles covered by the inflamed membrane, infiltrated with serum, sod- 

 den, and pale. Even a priori, it is not to be supposed that muscles in 

 this condition should be capable of a spasmodic contraction, and Ho- 

 kitansJcy declares his opinion, from a pathological point of view, that 

 " the infiltrated, pale, relaxed muscular tissue, hi croupous inflammation, 

 is stricken with palsy." That muscles in this condition really do lose 

 then* contractile power, is shown by the paralytic bulging of the inter- 

 costal muscles in pleurisy, and in the loss of peristaltic action of the in- 

 testine in peritonitis, or dysentery, from palsy of the intestinal muscles, 

 covered by the inflamed mucous or serous membrane. These, and 

 many other analogous observations, render it highly improbable that 

 the laryngeal muscles should be spasmodically contracted, instead 

 of palsied, where their mucous covering is inflamed. Section of the 

 par-vagum nerve, in young animals (an operation originally practised 

 for an entirely different purpose), furnishes absolute proof that paralysis 

 of the muscles of the larynx produces dyspnoea; nay, the dyspnoea 

 arising in consequence of this experiment bears so strong a resemblance 

 to croupous dyspnoea, is attended by such similar long-drawn whistling 

 inspiratory efforts, and other signs, that the similarity of the two con- 

 ditions must strike the most indifferent beholder. But the study of 

 the anatomy of the larynx of a child makes it certain that a forced 

 effort at inspiration will contract or close the glottis, unless it be held 

 open by muscular action. In childhood, we do not find that triangular 

 space, bounded by the base of the arytenoid cartilage, stretching for- 

 ward, and inward, to the processus vocales, known as the pars respira- 

 toria of Longet. In children, the base of the arytenoid cartilage has no 

 extension, the glottis forming a small cleft, running antero-posteriorly, 

 and bounded by the membranous expansion of the vocal chords. These 

 membranes lying obliquely opposed, one to the other, unless the glottis 

 be held open by muscular action, the effect of an energetic inhalation 

 must be to contract and close the cleft, by rarefying the air within the 

 trachea. 



