Caption

Large intestine mucosa. Coloured scanning electron micrograph (SEM) of the mucosa (lining) of the large intestine (colon) showing a fold in the wall. This is the caecum, the first part of the colon. Mucus (grey) can be seen on the surface. Folds of the colon provide a large surface area for absorptive cells to remove water and any remaining nutrients from the already digested food. Goblet cells, also in the mucosa, produce mucus which acts as a lubricant, assisting food and faecal movement and protecting the wall of the colon from mechanical damage. Magnification: x340 at 5x7cm size.