Disposition of muscularis propria and nerve elements in the lip of the ileocaecal valve.

The presence of a valve and the concept of a functional sphincter at the ileocaecal junction have been debated in the literature. Twenty four specimens of ileocaecal organ complex including 10cm of ileum and colon were obtained from cadavers from the Departments of Anatomy and Pathology, PGIMER, Chandigarh. 5 micron thick longitudinal sections from the upper lip of the ileocaecal valve were stained with Hematoxylin and Eosin and Silver stain. Sections of the ileum and colon from 5 ileocaecal organ complexes were also prepared and similarly stained. All the sections were viewed under the light microscope. The muscle bundles constituting the muscularis propria in the ileocaecal valve were arranged in two rows and were tapering in size from the base to the apex. The disposition of the muscle fibres was not uniform in all the specimens. The muscle fibers could be traced up to the upper, middle and lower third of the valve in 8 (33.3%), 14 (58.3%) and 2 (8.3%) specimens respectively. Silver stain of these sections revealed large numbers of nerve elements distributed within the submucosa and muscularis propria. The density of nerve elements in the ileocaecal valve was similar in all the sections irrespective of the extent of the muscularis propria and was comparable to the density of nerve elements in the muscularis propria and submucosa of the ileum and colon. The present study shows that the ileocaecal valve has a well developed muscularis mucosa and a proportionate component of the nerve elements.