absorption in the small intestine DEFINITELY IN EXAM

Question 1

how is the small intestine adapted for the absorption of food molecules

Answer 1

-the small intestine is very long
(provides a large surface area for the absorption of food molecules of digestion)
- the interior of the small intestine is covered with millions of villi
(villi increase the surface area for the absorption of molecules and the micro villi increase the surface area even further
this allows the rate of diffusion to be very past

Question 2

how are the villi adapted for diffusion

Answer 2

• villi have a very good blood supply so the bloodstream rapidly removes the products of digestion this increases the concentration gradient
• villi have a thin membrane which ensures a short diffusion pathway