3.4 Absorption And Assimilation

Question 1

What are the small intestines features to help with the process of absorption?

Answer 1

The inner wall of the SI is covered in folds to increase surface area, so more nutrients can be absorbed at once
Each fold is covered in villi and due to its thin wall, nutrients can diffuse easily across them
Each villi contains a large capillary network, where nutrients are absorbed into the blood and transported to where they are needed.
Each villi also contains lacteals which allow fat products to enter the lymphatic system.

Question 2

Why does absorption also occur in the large intestine?

Answer 2

Because there will be some remaining vitamins produced by the bacteria which are in the intestine, which need to be absorbed.

Question 3

What does the large intestine absorb from faeces?

Answer 3

Any remaining water from the faeces so it doesn’t go to waste.

Question 4

What is assimilation?

Answer 4

The process of both storing and synthesising new compounds from the absorber molecules.