THE INTESTINES 



253 



suddenly bending backwards along the left side of the 

 abdomen, it becomes the descending colon. This 

 reaches the middle line and becomes the rectum, which 

 is that part of the large intestine which opens externally. 



2>mC ^ 



^ncest.. 



Fig. si.— Diagram to show how the Wall of the Abdomen is made up, 



AKD HOW THE MeSENTERV SUPPORTS THE INTESTINE. 



The body is supposed to be cut across, and the intestine is represented 

 as the section of a strais-ht tube. In reality the space between the 

 intestine and the body wall is filled by the coils of the intestine and by 

 other organs. 



Vert, vertebra ; J.m, muscles of back ; «t. skin ; m>, m^, nt?, the three 

 muscle layers ; perit. peritoneum ; mes. mesentery ; intest. intestine ; b.v, 

 blood-vessels. 



The intestines are slung from the middle line, along 

 the vertebral column, of the abdominal cavity by a thin 

 membrane known as the mesentery. This consists 

 really of two layers between which the nerves, blood- 

 vessels and lymphatics lie which supply the intestines. 

 These layers are continued outwards on each side from 



