THE ABDOMEN 695 



ward direction, called the duodeno-jejunal flexure, which is sus- 

 pended from the left crus of the diaphragm by a fibro-muscular 

 band, called the musculus suspensorius duodeni. The jejunum and 

 ileum are very much convoluted, their coils being covered to a 

 greater or less extent by the great omentum. They lie below the 

 transverse colon, and occupy the umbilical, hypogastric, right and 

 left lumbar, and right and left iliac regions. A few coils of the 

 ileum sometimes dip into the pelvis, and when this occurs they 

 occupy, in the female, the pouch of Douglas. The jejunum and 

 ileum are attached to the vertebral column by a fold of peri- 

 toneum, called the mesentery proper, which contains their blood- 

 vessels, nerves, and lymphatics, and which is of such a nature as 

 to permit of great mobility in this part of the intestinal tube. They 

 are surrounded by peritoneum except along a narrow interval 

 corresponding with the attachment of the mesentery proper, this 

 border of the bowel being csJled the attached or mesenteric border, 

 as distinguished from the free or anti-mesenteric border. The small 

 intestine is a smooth cylindrical tube, which gradually diminishes 

 in size from above downwards. The terminal portion of the ileum, 

 as it is about to join the large intestine, is directed upwards and 

 to the right, with a slight inclination backwards. 



Meckel's DiTerticulam. — This is a protrusion which is sometimes found con- 

 nected with the free or anti-mesenteric border of the ileum about 3 feet above 

 the ileo-caecal valve. It represents the persistent proximal j>art of the vitel- 

 line or vitello-intestinal duct, which connects the yolk-sac with that portion 

 of the primitive aUmentary canal from which the lower part of the ileum is 

 formed. It usually measures from 2 to 3 inches in length, and its calibre 

 generally corresponds with that of the tube from which it springs. In most 

 cases it resembles the finger of a glove, but occasionally it is reduced to the 

 condition of a cord. It is rarely provided with a mesentery. 



The large intestine commences in the right iliac fossa, and termi- 

 nates at the anus. It measures about 6 feet in length, and 

 gradually diminishes in size from its commencement to its termi- 

 nation. It is composed of the colon and the rectmn. The colon 

 is subdivided into the caecum (with the vermiform appendix), 

 ascending or right colon, hepatic flexure, transverse or middle colon, 

 splenic flexure, descending or left colon, iliac colon, and pelvic colon. 



Caecum. — ^The caecum (caput caecum coli) is the commencement 

 of the large intestine. It represents that part of the gut which 

 extends below the ileo-caecEil orifice, and is situated in the right 

 iliac fossa, where it rests upon the ilio- psoas muscle with the 

 intervention of the fascia iliaca. Its lower end or fundus has an 

 inclination inwards towards the pelvic brim, close to which it 

 usually lies. The average length of the caecum is about 2^ inches, 

 its breadth being about 3 inches. When empty it is more or less 

 covered by coils of the ileum. In the distended state it comes 

 into contact with the anterior abdominal wall, and at the same 

 time it descends as low as the outer half of Poupart's ligament. 

 At its inner and back part, at a point about 2h inches from its 



