Lesson 8: Absorption

Question 1

What are the 3 adaptations of the small intestine?

Answer 1

• Folded walls into villi.
• Villi have good blood supply.
• Villi are one cell thick

Question 2

How does folded walls help absorption?

Answer 2

• Folded walls
• Increase surface area
• Nutrients have more contact
• Increases rate of diffusion between small intestine and blood in villi.

Question 3

How does a good blood supply help absorption?

Answer 3

• Good blood supply
• Mantain steep concentration gradient between small inestine and blood in villi.
• Increase rate of diffusion

Question 4

How does thin walls help absorption?

Answer 4

• Thin walls.
• Short diffusion pathway between small intestine and blood in villi.
• Increases the rate of diffusion.

Question 5

Why does the small intesine have a lot of muscle cells?

Answer 5

• Muscle cells help push food along.

Question 6

What is another transport method needed for absorption (other than diffusion?)

Answer 6

• When there is more nutrients in blood (villi) than small intestine, nutrients are absorbed by active transport.

Question 7

What are villi ?

Answer 7

Villi are finger - like projections on the lining of the small intestine.