Small Intestinal Crypt of Lieberkühn.You selected: introductionElectron micrograph of a mouse small intestinal crypt. The small intestine contains large finger-like projections (villi). A one-cell thick epithelium overlies each villus. The epithelium regenerates itself thorughout life, and serves not only as the initial site for processing nutrients absorbed from the lumen, but also acts as a barrier to prevent microbes in the lumen from crossing into the body.The base of intestinal villi extends into the crypts of Lieberkühn (one is shown here). Within the crypts multipotent crypt stem cells divide through life, giving rise to the epithelial lineages. Cells differentiate as they leave the crypt for the villus surface. Migration continues until cells are lost from the tip of a villus into the intestinal lumen. The exceptions are the intestinal Paneth cells which reside at the base of the crypts. Paneth cell | granule | lumen | undifferentiated crypt stem cell | lamina propria | nucleus | Information Module Name: crypt Module Title: Small Intestinal Crypt of Lieberkühn. Image Info: Electron micrograph taken by Lisa Roberts, 10,000X (?) magnification. Created by: Lynn Bry Contact Email:bryl@medicine.wustl.edu Last modified: Dec 12th, 1996. Created with Annotation 1.0 |