Colon. Light micrograph of a section through the mucosa (inner epithelial lining) of the colon (large bowel), showing the typical arrangement of invaginations of columnar epithelial cells forming simple tubular glands. The colonic glands consist of many goblet cells (pale), which secrete mucous to lubricate the epithelium, and epithelial absorptive cells (enterocytes), which extract water as part of the desiccation process for the formation of faecal material. This epithelium is a dynamic tissue and is replaced each week by cell renewal from stem cells residing at the base of the glands. Magnification: x70, when printed 10 centimetres wide.