MOVEMENTS OF THE ALIMENTARY CANAL. MASTICATION. 399 



responds with the trituration to which the Chemist would submit any solid mat- 

 ter, that he might present it in the most advantageous form to a digestive men- 

 struum. The complete disintegration of the alimentary matter is, therefore, of 

 great consequence; and, if imperfectly effected, the subsequent processes are 



Fig. 116. 



A view of the Organs of Digestion, opened in nearly their whole length ; a portion of the oesophagus has 

 been removed on account of want of space in the figure ; the arrows indicate the course of substances along 

 the canal:' 1, the upper lip, turned off the mouth; 2, its frsenum; 3, the lower lip, turned down; 4, its frse- 

 num ; 5, 5, inside of the cheeks, covered by the lining membrane of the mouth ; 6, points to the opening of 

 the duct of Steno; 7, roof of the mouth; 8, lateral half arches; 9, points to the tonsils; 10, velum pendulum 

 palati ; 11, surface of the tongue ; 12, papillae near its point ; 13, a portion of the trachea ; 14, the oesophagus ; 

 15, its internal surface ; 16, inside of the stomach ; 17, its greater extremity or great cul-de-sac ; 18, its lesser 

 extremity or smaller cul-de-sac; 19, its lesser curvature; 20, its greater curvature; 21, the cardiac orifice; 22, 

 the pyloric orifice ; 23, upper portion of duodenum; 24, 25, the remainder of the duodenum; 26, its valvulae 

 conniventes ; 27, the gall-bladder ; 28, the cystic duct ; 29, division of hepatic ducts in the liver ; 30, hepatic 

 duct ; 31, ductus communis choledochus ; 32, its opening into the duodenum ; 33, ductus Wirsungii, or pan- 

 creatic duct ; 34, its opening into the duodenum ; 35, upper part of jejunum ; 36, the ileum ; 37, some of the 

 valvulse conniventes; 38, lower extremity of the ileum; 39, ileo-colic valve; 40, 41, coecum, or caput coli; 42, 

 appendicula vermiformis; 43, 44, ascending colon; 45, transverse colon; 46, 47, descending colon; 48, sigmoid 

 flexure of the colon ; 49, upper portion of the rectum ; 50, its lower extremity; 51, portion of the levator-am 

 muscle ; 52, the anus. 



