i668 HUMAN ANATOMY. 



cations : one with nodes in the mesentery ; one with nodes on the left of the as- 

 cending colon behind the peritoneum ; one with nodes of the iliac fossa ; and, in 

 the female, one with the system of the ovary. There is a constant lymph-node at 

 the angle between the ileum and colon. ^ 



The nerves supplying the caecum and appendix are derived from the superior 

 mesenteric plexus. Their mode of distribution within the gut has already been 

 given (page 1643). 



Development and Growth. — At birth and for some years after the caecum 

 is very small and the foetal or cornucopia shape is more frequent than later. The 

 appendi.x is relatively rather long. In eleven cases below ten years Berry" found the 

 average length of the caecum 28 mm. and the breadth 37 mm. In eighteen cases 

 he found the average length of the appendix 74 mm. (2^ in.). Ribbert gives the 

 following lengths of the appendix : at birth, 34 mm. ; up to five years, 76 mm. 

 (3 in.); from five to ten years, 90 mm. (3^2 in.). 



At birth the caecum is usually higher than in the adult, since it has not de- 

 scended to its permanent position and the adhesion of the mesentery of the ascend- 

 ing colon has not occurred in the lower part of the flank. It is often rather above 

 the anterior superior spine of the ilium. In five of about thirty-five observations 

 on young children, mostly newly-born, it was so free from fixed attachment that it 

 could hardly be said to have any definite position. 



THE COLON. 



The ascendmg- co/on extends from the caecum to the under side of the liver, 

 where it makes a sudden bend — the hepatic Jiexure (flexura coli dextra) — and be- 

 comes the transverse colon, which crosses the abdomen to the splenic flexure (flexura 

 coli sinistra) at the spleen, whence, as the descendi?ig colon, it passes to the crest of 

 the ilium. From that point to the middle of the third sacral vertebra it is known as 

 the sigmoid Jiexure. The three bands of the colon, or tcsnice coli, formed by accu- 

 mulations of longitudinal fibres, are each about i cm. broad. Their disposition in 

 the walls of the gut is difficult to follow and is not constant. The following arrange- 

 ment is probably the most usual. In the ascending colon one is in front and two 

 behind, one of the latter being near the outer and the other near the inner aspect. 

 On reaching the transverse colon, the anterior becomes the inferior, while the 

 external becomes the superior, receiving the attachment of the transverse meso- 

 colon. The internal also lies on the upper surface, but behind the preceding. On 

 the descending colon they resume their original positions, but tend to grow indis- 

 tinct. They are still more so in the sigmoid flexure, and before the rectum is 

 reached there are but two bands, an anterior and a posterior, of which the latter is 

 the stronger. The interior of the colon shows the sacculated condition, but there 

 are no folds or valvulae conniventes like those of the small intestine. The solitary 

 lymph-nodules continue, much like those of the jejuno-ileum. 



Relations. — The ascending colon is in the right flank against the psoas and 

 quadratus lumborum, but does not overlap the latter unless greatly distended. It 

 lies in front of the lower end of the right kidney, projecting but little beyond its 

 outer border, with the second part of the duodenum on its inner side. It ends with 

 the hepatic flexure, which makes a large impression on the under side of the right 

 lobe of the liver directly anterior to the kidney. It is often completely covered in 

 front by the small intestine. 



The transverse colon is suspended between its beginning, the hepatic 

 flexure, and its end, the splenic flexure, like a festoon, forward and downward ; 

 for the ends are near the back of the abdominal cavity. The splenic flexure, in front 

 of the lower part of the spleen, is both higher and more posterior than the hepatic 

 one. The transverse colon is covered above and in front by the greater omentum. 

 It runs along the liver, touching the gall-bladder and the greater curvature of the 

 stomach, around which it ascends to the spleen. The splenic flexure may or may 



' Lockwood : Proceedings of the Anatomical Society of Great Britain and Ireland, Journal 

 of Anatomy and Physiology, vol. xxxiv., 1900. 

 * Anat. Anzeiger, Bd. x., 1895. 



