THE ILEO-COLIC VALVE. 



diameter and thickly studded with lymphoid follicles, may represent a 

 condition of the appendix. 



Ileo-csecal or ileo-colic valve. — The lower part of the small intestine 

 (fig. 271 /), ascending- from left to right, and from before backwards, 



Fig. 271. — View of the Ileo-colio 

 Valve from the Large Intestine 

 (after Sautorini). i 



The figure shows the lowest part of the 

 ileum, i, joining the ca'cuiu, c, and the 

 ascending colon, o, which have been 

 opened anteriorly, so as to display the 

 ileo-colic valve ; «, the lower, and e, the 

 upper .segment of the valve. 



enters the commencement of the 

 large intestine, with a consider- 

 able degree of obliquity, about 

 two inches and a half from the 

 bottom of the cascum, and opposite 

 the junction of the latter with 

 tlie ascending colon. The open- 

 ing leading from the ileum into 

 the large intestine is guarded by 

 a valve composed of two seg- 

 ments or folds. This is the ileo- 

 cecal or ileo-colic vcdvc : it is also 

 called the valve of Bauhin and 



the valve of Tulpius, although Fallopius had described it before either of 

 those anatomists. 



The entrance between the two segments of the valve is a narrow 

 elongated slit-like aperture, lying nearly transverse to the direction of 

 the great intestine. It is rounded and widened at its anterior end 

 which is turned slightly to the left, but the posterior end is narrow, 

 and pointed. It is bounded above and below by two prominent semi- 

 lunar folds, which project inwards towards the caecum and colon. The 

 upper of these (fig. 271, e) is horizontal in direction, the lower and 

 larger (a) more oblique. At each end of the aperture these folds 

 coalesce, and are then prolonged as a single ridge on each side for some 

 distance round the cavity of the intestine, forming the frcma or 

 rctinac}ila of the valve. The opposed surfaces of the valvular folds 

 which look towards the ileum, and are continuous with its mucous sur- 

 face, are covered like it with villi ; while their other surfaces, turned 

 toward the large intestine, are smooth and destitute of villi. When the 

 cKcum is distended, the frajna of the valve are stretched, and the mar- 

 ginal folds brought into apposition, so as completely to close the aper- 

 ture and prevent reflux into the ileum, while at the same time no 

 hindrance is oflTered to the passage of additional matter from thence into 

 the great intestine. 



Each segment of the valve consists of two layers of mucous mem- 

 brane, continuous with each other along the free margin, and including 

 between them, besides the submucous areolar tissue, a number of mus- 

 cular fibres, continued from the circular fibres of the ileum and of the 

 large intestine. The longitudinal muscular fibres and the peritoneal 



