STRUCTURE OF THE PHARYNX. 491 



pharynx, the communication of the nose, mouth, and windpipe, 



with this cavity, will be seen from behind at one view. 



The openings into the nose, or the posterior nares, appear 



uppermost. Their figure is irregularly oval, or oblong ; they 



are separated from each other by a thin partition, the vomer. 



Immediately behind, on the external side of each of these orifices, 



is the Eustachian tube. (See fig. 118, p. 454.) 



The soft palate will appear extending from the lower 



boundary of the posterior nares, obliquely backwards and 



downwards, so as nearly to close the passage into the mouth. 



The uvula hangs from it ; and, on each side of the uvula, the 



edge of the palate is regularly concave. 



Below the palate, in the isthmus of the fauces, are the 



ridges or half arches, and the tonsils between them. The half 



arch which presents first, in this view, runs obliquely downward 



and backward, and not parallel to the other. 



Close to the root of the tongue is the epiglottis erect ; and 



immediately adjoining it, is an aperture large enough to admit 



the end of a middle-sized finger. This aperture is widest at 

 the extremity next to the epiglottis, and rather narrower at the 

 other extremity : it is the glottis or opening of the windpipe. 



When the larynx is elevated, the epiglottis can be readily 

 depressed so as to cover it completely. 



The extremities of the arytenoid cartilages, and their 

 appendices, may be recognized at the posterior edge of the 

 glottis. At a short distance below this edge, the oesophagus 

 begins. 



The Pharynx is composed of the membrane continued from 

 the nose and mouth internally, and of a stratum of muscular 

 fibres externally. The internal membrane is very soft and 

 flexible and perforated by many muciferous ducts. The 

 surface which it forms is rather rough, owing to the mucous 

 glands which it covers. It has a red color, but not so deep 

 as that of some other parts. It is connected to the muscular 

 stratum by a loose cellular membrane. 



The muscular coat consists of three different portions, which 

 are considered as so many distinct muscles. They are called 



