CATARRH. 405 



Here the mucosa lodges tlic most important glandular organs, 

 while its surface and its component tissues are modified in 

 accordance with the functions which it has to perform : e.cj, 

 for purposes of absorption it is important that as wide an area as 

 possible should be brought in contact with the chyme ; we find 

 this requirement met b>^ the villi with Avhich the alimentary 

 inucous membrane is beset from the duodenum downwards, each 

 villus containing a lymphatic radicle in its axis ; and in order 

 still more to facilitate absorption, we find the layer of connective 

 tissue which intervenes l^etween the vessels and the epithelium, 

 presenting in a very high degree the properties of lymphadenoid 

 tissue, with whose structure we first became acquainted in the 

 lymphatic glands. The absorbent apparatus includes moreover 

 the numerous follicular (conglobate, Ilenle) glands ; the solitary 

 glands, the patches of Feyer^ the tonsils, and the saccular glands 

 at the root of the tongue. These may be said to form the first 

 stage on the road, which the matters to be absorbed by the 

 lymphatic system have to traverse. Should these matters 

 happen to be pathological irritants, their path is marked by 

 liypera^mia, inflammation and morbid growth ; hence it is, that 

 in so many of the general disorders of the entire alimentary 

 tract, we find these follicular structures peculiarly involved. 



Of the secreting glands, it is only the smaller ones, the 

 simple tubular glands, which are situated in the thickness of the 

 mucous membrane, while those of larger size, the follicular 

 mucous glands, are mainly embedded in the submucous tissue. 

 Nevertheless, some mucous membranes are inordinately rich in 

 glandular structures; e.cj, the gastric mucous membrane has 

 five-sixths of its bulk made up of gland-substance. 



About the submucous tissue there is not much to be said ; 

 we shall find it a peculiarly favourable locality for the develop- 

 ment and spread of morbid growths, Avhen these come to be 

 discussed. 



a. Inflammation. 



1. Catai'ihal Inflammation. — Catarrh. 



§ 340. The larger half of all the diseases to which humanity 

 is liable, consists of catarrhal affections of mucous membranes. 



