THE ALIMENTARY CANAL 



351 



Many of these ducts possess small cystic dilatations which are found in 

 the connective tissue of the corium or occasionally in the submucosa. 



SUPERFICIAL GLANDS. At about the level of the cricoid cartilage 

 the esophageal mucous membrane presents 

 two lozenge-shaped depressions, one on 

 either side, whose diameter varies from 1 

 centimeter down to microscopical size. 

 These areas mark the site of the superficial 

 glands of the esophagus (Hewlett) or up- 

 per cardiac glands (Schafer). These are 

 short branched tubular glands which 

 closely resemble those of the cardiac re- 

 gion of the stomach. They are con- 

 fined to the mucous membrane; their 

 tubules, in marked contrast to those of 

 the deep mucous glands of the esoph- 

 agus, never penetrating the muscularis 

 mucosa?, which, however, is considerably 

 thinned beneath the superficial glands 

 These glands secrete a mucinous fluid, 

 but their cells are not so strongly ba- 

 sophilic as those of true mucous glands 

 such as the deep glands of the esoph- 

 agus. The ducts of the superficial 

 glands, as well as their secreting por- 

 tions, and also the lining epithelium of 

 the esophagus upon which they open, are 

 clothed with columnar epithelial cells. 

 Many of the secreting tubules contain 

 parietal cells similar to those of the fun- 

 dus glands of the stomach. Both ducts 

 and secreting tubules contain small, cystic 

 dilatations. 



At the lower end of the esophagus a 

 similar group of superficial glands, the 

 lon-er cardiac glands of the esophagus, fre- 

 quently mark the beginning transition to 

 the structure of the cardiac portion of the 

 stomach, with whose glands they are con- 

 tinuous. 



FIG. 328. FROM A SECTION OF 



THE HUMAN ESOPHAGUS. 

 a, slight cornification of sur- 

 face epithelium; 6, Str. ger- 

 minativum; c, L. propria mu- 

 cosse; d, L. muscularis mucosae. 

 (Goetsch, Am. Jour. Anat., 10, 1, 

 1910.) 



