Key area 2.7 - Absorption of materials

Question 1

Why does blood need to carry oxygen and nutrients ?

Answer 1

They must be absorbed in the blood stream to be delivered to cells for respiration

Question 2

What do all surfaces involved in absorption of materials have in common ?

Answer 2

Large surface area
Thin walls
Extensive blood supply

Question 3

Name the two structures involved in the absorption of materials

Answer 3

Alveoli in the lungs
Villi in the small intestine

Question 4

Describe alveoli

Answer 4

Lungs have a large number of alveoli producing a large surface area

Oxygen and carbon dioxide are absorbed through the thin alveolar walls to or from blood capillaries

Alveoli have :
Large surface area
Thin walls
Extensive blood supply
Large amount of them to make the large surface area

Question 5

Describe the structure and function of the villi

Answer 5

There are millions of villi in the small intestine

Part of the villus

Blood Capillary :
Absorbs - Glucose and Amino acids

Digested from - Starch and proteins

Lacteal :
Absorbed - Glycerol and fatty acids

Digested from - Fats

Features to carry it out effectively are same as alveoli