23 Pages


Most absorption in the gut of a mammal takes place in the small intestine, that shows a number of adaptations. The surface area is increased enormously by the possession of small finger-like projections known as villi. In addition, the epithelial cells that line these are covered in microvilli. The cytoplasms of the epithelial cells contain large numbers of mitochondria that provide the ATP necessary for active transport of substances from the epithelium of the gut.