2OO NORMAL HISTOLOGY AND ORGANOGRAPHY. 



Tania coll. 



Sacculcs. 



3. Muscularis. The muscularis consists of an 

 inner circular and an outer longitudinal layer of 

 smooth muscle. The inner circular is the heavier of 

 the two and by its contraction produces many longi- 

 tudinal folds in the mucosa. Smooth muscle, wher- 

 ever found, is associated with connective-tissue 

 elements, but the smooth muscle of the intestine 



has a less suppl} 

 of this than the 

 smooth muscle any 

 other place in the 

 body. 



4. Serosa. This 

 layer is identical 

 with the serosa de- 

 scribed in the wall 



Fig. 149. Portion of large intestine. of the Stomach. 



LARGE INTESTINE* 



The average length of the large intestine is five 

 feet. Its divisions are given on page 128. It is dis- 

 tinguished from the small intestine by the following 

 external features : tcznicz coli, sacculce, and appendices 

 epiploiccE. 



TcenicB Coli. In the large intestine the longitudinal 

 muscle is gathered into three bands or strips known 

 as taeniae coli. Each band is about one-quarter inch 

 wide and one foot shorter than the intestine to 

 which it belongs. The large intestine, therefore, 

 becomes sacculated that is, it is divided by the 

 three longitudinal muscle bands into three rows of 

 sacculae. If the bands be dissected away the saccules 



