Absorption into small intestine. Flashcards
1
Q
What is the duty of the small intestine?
A
- Products of digestion are absorbed into the blood stream into the small intestine.
2
Q
What is the first adaptation of the small intestine to digest these molecules?
A
- It is very long (Human SI is 5m).
- ## Provides a large surface area for the absorption of the products formed during digestion.
3
Q
What is the first adaptation of the villi inside of the small inestine?
A
- Interior of small intestine is covered in Villi.
- Increases the surface area for the absorption of molecules.
+ Microvilli on the surface increases further SA.
4
Q
What is the second adaptation for villi?
A
- Very good blood supply.
- Bloodstream removes rapidly the products of digestion.
- Increases concentration gradient.
5
Q
What is the 3rd adaptation of the villi?
A
- Thin membrane.
- # Ensures a small diffussion pathway.
6
Q
What do all of these features mean?
A
- Means that there is a rapid rate of diffusion.
- Any molecules that cannot be absorbed by diffusion is absorbed by active transport.