Absorption of materials

Question 1

Describe blood and tissue functions

Answer 1

Oxygen and nutrients from food must be absorbed into the bloodstream to be delivered to cells for respiration.
Waste materials such as carbon dioxide, must be removed from cells into the bloodstream.

Tissues contain capillary networks that allow the exchange of materials to a cellular level.

Question 2

Describe features of surfaces involved in the absorption of material

Answer 2

Surfaces involved in the absorption of materials have certain features in common:

Large surface area

Thin walls

Extensive blood supply

These increase the efficiency at which materials are absorbed.

Question 3

Label and describe the function of the lungs

Answer 3

1. Trachea
2. Bronchi
   3, Brionchioles
3. Alveoli

The lungs are the gas exchange organs. They consist of a large number of alveoli providing a large surface area for gas exchange.

Oxygen into the blood is exchanged for carbon dioxide out of the blood.

Question 4

Describe how oxygen and carbon dioxide are exchanged in the lungs

Answer 4

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

Question 5

Describe where nutrients are absorbed into the blood

Answer 5

Nutrients from food are absorbed into the blood in the small intestine.

The small intestine contains a large number of thin-walled villi to provide a large surface area for this absorption.

Question 6

Describe the structure and function of the villi

Answer 6

The network of capillaries within the villi absorbs glucose and amino acids.

The lacteal absorbs fatty acids and glycerol.