Crypts of Lieberkuhn. Light micrograph (LM). Crypts of Lieberkuhn of the colon shown in cross section. Crypts are long blind-ending tube-like extensions of the surface epithelial lining of the gut. In the small intestine they comprise several cell types including mucus-secreting goblet cells and absorptive enterocytes around a narrow central lumen. Crypts also contain gut epithelial stem cells. Connective tissue supporting the crypts contains fibroblasts, nerves, blood vessels, and white blood cells. Human tissue