276 



THE DIGESTIVE SYSTEM 



superficial glands of the esophagus (Hewlett *) or upper cardiac 

 glands (Schafferf). These are short branched tubular glands 

 which closely resemble those of the cardiac region of the stomach. 



They are confined 

 to the mucous 

 membrane ; their 

 tubules, in marked 

 contrast to those of 

 the deep mucous 

 glands of the eso- 

 ^ phagus, never pene- 

 ' trating the muscu- 

 laris mucosae,which, 

 however, is consid- 



_ <***-._ &f erably thinned be- 



?^ neath the super- 

 ficial glands. These 



^'r glands secrete a 



mucinous fluid, but 

 their cells are not 

 so strongly baso- 

 phile as those of 

 true mucous glands 

 such as the deep 

 glands of the eso- 

 phagus. The ducts of the superficial glands, as well as their 

 secreting portions, and also the lining epithelium of the esopha- 

 gus upon which they open, are clothed with columnar epithelial 

 cells. Many of the secreting tubules contain parietal cells similar 

 to those of the f undus 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 cardiac glands of the esophagus, frequently mark the 

 beginning transition to the structure of the cardiac portion of the 

 stomach, with whose secreting glands they are continuous. 



The lining epithelium of the esophagus is of the stratified 

 squamous variety. Its attached surface is indented by the papillae 

 of the corium ; its free surface is smooth. In the collapsed state 

 of the organ its mucous membrane is thrown into longitudinal folds 

 or rugae and its lumen is obliterated. The small isolated areas of 



FIG. 228. FROM A SECTION OF THE SUPERFICIAL GLANDS OF 



THE HUMAN ESOPHAGUS. 



a, esophageal epithelium ; , superficial glands ; c, mucous 

 glands; rf, tunica propria; e, muscularis mucosae. Hemat- 

 oxylin and eosin. Photo, x 17. (After Hewlett.) 



* Jour. Exper. Med., 1901. 



f Sitz. d. Wien. Akad., 1897. 



