Role in the small intestineEdit
Villi significantly increase the rate of diffusion of soluble food molecules in the small intestine through a variety of means:
- They are folded to provide a large surface area over which diffusion can take place. They additionally have microvilli to further increase the surface area for diffusion.
- They have a large, constant blood supply to maintain a steep concentration gradient.
- Their walls are only one cell thick to provide a short diffusion path.