Regional and age-related differences of crypts in the human large intestine: A 3-D surface metrology study

Large intestinal crypts are tightly packed tubular indentations of the epithelium that act both as an absorptive surface and as a protective barrier. The crypt base consists of stem cells involved in the continuous regeneration of the intestinal surface. Thus, these crypts serve as the etiology of 95% of colon cancer and other colon-related pathologies such as inflammatory bowel disease. However, we still need a better understanding of these important structures in the human intestine. We collected and scanned four different regions of the large intestine (cecum, descending colon, sigmoid colon, and rectum) from 15 cadavers to study the surface characteristics of the crypts such as crypt density, opening area, depth, and volume. The cecum had a significantly larger crypt opening area when compared to the rectum. Further analysis showed that this difference is age dependent and only observed in older cadavers. The rectum also showed age-dependent changes in crypt depth. The varying morphology of crypts between the proximal/distal regions and individuals could be attributed to functional differences and naturally occurring adaptations to protect areas of the colon that are more susceptible to colon-related pathologies.