500 A MANUAL OF ANATOMY. 



The Large Intestine. Figs. 96, 97, 98, 101, IO2. 



Reaches from the right inguinal region, upward and 

 across the abdomen, then descends along the left side, to 

 pass into the pelvic cavity. 



It has a length of five and one-half feet, and a diameter 

 of two inches. 



The large intestine is not only larger than the small, but 

 is distinguished from it by pendent masses of fat covered by 

 peritoneum appendices epiploica, and by having three bands 

 of muscular tissue longitudinally disposed upon its exterior, 

 one posteriorly at the mesenteric attachment, one anteriorly, 

 and one internally. These bands being shorter than the 

 bowel give it a sacculated appearance. 



Its blind extremity, below the junction of the ileum, is 

 the caecum. 



The caecum lies in the right lumbar or inguinal region. 

 It is about two and one half inches long and about three 

 inches wide. From its lower, posterior surface the vermi- 

 form appendix comes off, and lies usually in a direction up- 

 ward and to the left, but often the appendix may hang down 

 into the pelvic cavity, or take any other position about the 

 lower end of the caecum. The caecum and appendix are usu- 

 ally entirely enclosed by peritoneum (the appendix having 

 a distinct, though small mesentery), and are free within the 

 abdominal cavity, consequently any pus coming from the 

 interior of either would be discharged into the general 

 abdominal cavity and start up a (usually) fatal peritonitis, 

 unless the exudation is shut off by inflammatory adhesions 

 agglutinating the adjacent intestines together, to form a 

 local pus cavity. 



The point at which the appendix joins the caecum is on 

 the ilio-umbilical line (from anterior superior spine of ilium 

 to umbilicus) at a distance from the iliac spine of two and 



