1) There is muscular tissue all the way down the alimentary canal
2) Its job is to squeeze balls of food (called boluses) through your gut otherwise it would get clogged up
3) The squeezing action, which is waves of circular muscle contractions, is called peristalsis.
1) The small intestine is adapted for the absorption of food
2) It's very long, so there's time to break down and absorb all the food before it reaches the end
3) There is a really big surface area for absorption, because the walls of the small intestine are covered in millions and millions of tiny little projections called villi
4) Each cell on the surface of a villus has its own microvilli - little projections which increase the surface area even more
5) Villi have a single permeable layer of surface cells and a very good blood supply to assist in quick absorption