HAUSTRAL SEPTATIONS INCREASE AXIAL AND RADIAL-DISTRIBUTION OF LUMINALCONTENTS IN GLASS MODELS OF THE COLON

We used two glass models of the colon to test the hypothesis that lumi nal septations increase efficiency of flow. Each was a straight glass tube 4 cm in diameter and filled with water. One had four septations n arrowing the lumen to 2 cm; the other had no septations. For each run, liquid dye and one solid test particle were placed at one end of the model. A single pressure pulse was applied to the dye and particle. Th e distance each traveled was compared using analysis of variance. The nonseptated model had poor mixing of dye, and the particle moved only short distances. In the septated model, there was thorough mixing of d ye and the particle moved rapidly along what appeared as a central cor e of high-velocity liquid flow from one septal opening to another. Com pared with the nonseptated model, this produced statistically signific ant increases in the distances traveled by means of 32 (dye) and 90% ( particle). Our studies suggest that septations in a tubular organ faci litate intraluminal mixing and flow of liquids and solids.