166 THE ESSENTIALS OF HISTOLOGY. 



on the upper surface of the soft palate with ciliated epithelium, which 

 is continuous with that of the nostrils, and through the Eustachian 

 tube with that of the tympanum. Below the level of the soft palate 

 the epithelium is stratified like that of the mouth and gullet, into 

 which it passes. In certain parts the mucous membrane contains a 

 large amount of lymphoid tissue, especially at the back, where it 

 forms a projection which is sometimes termed the pharyngeal tonsil, 

 and there are numerous mucous glands opening on its surface. 



The oesophagus or gullet, which passes from the pharynx to the 

 stomach, consists, like the pharynx, of a jibrom covering, a muscular 

 wat, a lining mucous membrane, and intervening connective tissue 

 (areolar coat) (fig. 196). The muscular coat is much more regularly 

 arranged than that of the pharynx, and is composed of striated muscle 

 in about its upper third only, the rest being of the plain variety. There 

 are two layers of the muscular coat, an outer layer, in which the fibres 

 run longitudinally, and an inner, in which they course circularly. The 

 mucous membrane is lined by a stratified epithelium, into which micro- 

 scopic papilla? from the corium project. The corium is formed of areolar 

 tissue, and its limits are marked externally by a narrow layer of longi- 

 tudinally disposed plain muscular fibres, the muscularis mucosce. This 

 is separated from the proper muscular coat by the areolar coat, which 

 contains the larger branches of the blood-vessels and lymphatics, and 

 also most of the mucous glands of the membrane. 



