82 PHYSIOLOGY. 



A portion of the stomach, showing its internal surface or mucous coat. 



16^ The mucous coat is the seat of some of the most im- 

 portant functions of the economy ; in the lungs, of respira- 

 tion ; in the stomach, of digestion. ; and in the mouth and 

 nose, of taste and smell, &c., and forms, with scarcely an 

 exception, a continuous wholeJ That portion which lines 

 the eyes and eye-lids, is connected with that which lines the 

 nostrils, by means of the nasal canal ; while that which lines 

 the mouth, meets in the throat with that which comes 

 down from the nose. In the fauces it divides, and while one 

 portion goes down the windpipe into the lungs, the other 

 passes down the esophagus into the stomach, forming a lining 

 for the whole tract of the intestinal canal. 



17. Mucous membranes are of a loose, spongy texture, of 

 a reddish colour, and are largely supplied with blood-vessels 

 and nerves. They are also numerously supplied with small 

 glandular bodies called mucous glands or folicles. (The 

 chief use of these membranes is, to sheath and protect the 

 inner surfaces of the body, as the skin does the outer, and by 

 means of the mucus, with which they are always covered in 

 a state of health, to guard them against the contact of irri- 

 tating substances. 



