386 



THE DIGESTIVE SYSTEM 



tivity. During rest the granular 

 until the non-granular zone is r 

 extremity and the nucleus is obsc 

 The cell becomes therefore much i 

 obliterated. During activity the 

 the lumen; the cell shrinks and 

 more distinct, and the granular 



(ecretion accumulates within the cell, 

 duced to a narrow rim at its basal 

 red and pushed somewhat basalward. 

 \vollen and the alveolar lumen almost 

 y mo gen granules are discharged into 

 >ecomes clearer; the nucleus appears 

 zone becomes progressively narrower, 

 the basal non-granular 

 zone being copespon- 

 dingly increased in 

 breadth. In this basal 

 zone elongated gran- 

 ules have been demon- 

 strated, which in part 

 are to be regarded as 

 prozymogen i ('basal 

 filaments' of Solger), 

 in part (repealed by 

 special technic) as 

 mitochondria! 



The seroiite cells 



are provided 



nth sys- 



FIG. 



356. A GROUP OF Mucous ACINI, FROM THE 

 HUMAN SUBM AXILLARY GLAND. 



a-a, interlobular connective tissue. Hematein and 

 eosin. Photo. X 510. 



terns of secrc 

 naliculi whic 

 ning at the | 

 lumen, invesl 



tory ca- 

 , begin- 

 andular 

 the cell 



with a network of 

 canals which lie in the 

 intercellular substance 



and may even send short offshoots or intracellular canaliculi into the 

 body of the cell itself. These canaliculi are considered to be character- 

 istic of the serous acini and are not found in relation with the' cells of 

 the mucous acini (Fig. 358). 



THE Mucous ACINI. The mucous acini may contain only mucus- 

 secreting epithelium, or they may also include ceEtara-iinely granular 

 acidophil cells which resemble the epithelium of the serousglands. The 

 former variety of acinus is found in the mucous glands at the base 

 of the tongue and in the soft palate; the latter in the sublingual gland, 

 in the lingual glands of Nuhn, and in the mucous glands of the lips 

 and cheeks. 



