72 ELEMENTARY PHYSIOLOGY 



duodeni, twelve), being considered to be about twelve finger- 

 breadths long. The upper two -fifths of the remainder is called 

 the jejunum, and the lower three-fifths the ileum (Gr. illo, I twist). 

 There are, however, no distinct lines of separation between these 

 three parts. The large intestine is a wider tube, about six feet 

 long, and varying in width from one inch and a-half to two inches 

 and a-half. It is divided into the ctzcum, colon, and rectum. The 

 caecum or blind intestine (Lat. tacus, blind) is a kind of pouch, 

 situated on the right side of the abdomen, below the junction of 

 the small intestine (the ileum) with the large intestine. The colon 

 extends upwards from this point, till it reaches the level of the 

 lower surface of the stomach ; it then turns to the left, passing 

 under the stomach, and is again deflected downward till it termi- 

 nates in the rectum (Lat. straight) the last part of the intestines. 

 Thus the colon is arranged like three sides of a square, the parts 

 being called the ascending, transverse, and descending colon 

 respectively. The mouth, pharynx, oesophagus, stomach, and 

 intestines together form the alimentary canal (Lat. alimentum, 

 nourishment), and each part does its share in the digestion of the 

 food and the separation of the nutritious from the non-nutritious 

 portions. 



The liver is a very large reddish-brown organ, consisting of 

 two lobes or parts the right and the left and weighing three or 

 four pounds. The uppersurface of the liver is convex and smooth, 

 and fits closely against the under and concave surface of the 

 diaphragm. The right lobe is larger than the left, and extends 

 well over the right side of the abdomen, touching the intestines 

 and right kidney ; while the smaller and left lobe crosses the 

 middle line and partly covers the stomach. The liver prepares a 

 fluid called the bile, which assists in the process of digestion. 

 This bile is stored in a bladder called the gall-bladder, situated 

 on the under surface of this organ. 



The pancreas (Gr. pan, all ; and kreas, flesh) or sweetbread 

 is another organ which prepares a digestive fluid the pancreatic 

 juice. It lies just behind the stomach and extends from the duo- 

 denum to the spleen. It is about seven inches long and one and 

 a-half wide, and weighs about three ounces. The fluid which 

 it prepares is conveyed into the duodenum by the pancreatic 

 duct. * 



The spleen or milt is a dark purple-grey organ, weighing 

 about six ounces, and situated closely against the cardiac extremity 

 of the stomach. It is engaged in the production of some of the 

 constituents of the blood. 



The kidneys are two bean-shaped organs, measuring about 



