404 THE HUMAN BODY 



muscular elevations covered by mucous membrane, which reach 

 from the soft palate to the tongue. These elevations are the pillars 

 of the fauces. Each bifurcates below, and in the hollow between its 

 divisions lies a tonsil (7, Fig. 128), a soft rounded body about the 

 size of an almond, composed of lymphoid tissue (Chap. XXII). 

 The tonsils not unfrequently become enlarged during a cold or sore 

 throat, giving rise to considerable discomfort. 



The Pharynx or Throat-Cavity (Fig. 122). This portion of the 

 alimentary canal may be described as a conical bag with its broad 

 end turned upwards towards the base of the skull, and its narrow 

 end downwards and passing into the gullet. Its front is imperfect, 

 presenting -openings which lead into the nose, the mouth, and 

 (through the larynx and windpipe) the lungs. Except during 

 swallowing or speech the soft palate hangs down between the 

 mouth and pharynx ; during deglutition it is raised into a horizon- 

 tal position and separates an upper or respiratory portion of the 

 pharynx from the rest. Through this upper part, therefore, air 

 alone passes, entering it from the posterior ends of the two nostril- 

 chambers ; while through the lower portion both food and air pass, 

 one on its way to the gullet, b, Fig. 122, the other through the 

 larynx, d, to the windpipe, c; when a morsel of food "goes the 

 wrong way" it takes the latter course. Opening into the upper 

 portion of the pharynx on each side is an Eustachian tube, g; so 

 that the apertures leading out of it are seven in number; the two 

 posterior nares, the two Eustachian tubes, the fauces, the opening 

 of the larynx, and that of the gullet. At the root of the tongue, 

 over the opening of the larynx, is a plate of cartilage, the epiglottis, 

 e, which can be seen if the mouth is widely opened and the back 

 of the tongue pressed down by some such thing as the handle of a 

 spoon. During swallowing the epiglottis is pressed down like a lid 

 over the air-tube and helps to keep food or saliva from entering it. 

 In structure the pharynx consists essentially of a bag of connective 

 tissue lined by mucous membrane, and having muscles in its walls 

 which drive the food on. 



The Esophagus or Gullet is a tube commencing at the lower 

 termination of the pharynx and which, passing on through the 

 neck and chest, ends below the diaphragm by joining the stomach. 

 In the neck it lies close behind the windpipe. It consists of three 

 coats a mucous membrane within; next, a submucous coat of 



