Gas exchange

Question 1

Outline

Answer 1

we need to get oxygen from the air into the blood + we need to remove waste carbon dioxide from the blood into the air. moving gases like this is called gaseous exchange
the alveoli are adapted to make gas exchange in lungs happen easily + efficiently

Question 2

Features of alveoli

Answer 2

they give the lungs a big surface area
they have moist thin walls (one cell thick)
they have a lot of capillaries

Question 3

How does it work?

Answer 3

the gases move by diffusion from where they have a high concentration to where they have a low concentration

• oxygen diffuses from air into the alveoli into blood
• carbon dioxide diffuses from blood into the air in the alveoli