Lung gas exchange

Question 1

Journey of air in

Answer 1

Air enters via trachea
Splits into bronchi passing into each lungs
Split further into bronchioles
At each end have alveoli
Diffuse through into blood

Question 2

Rings of cartilage

Answer 2

Inside the trachea to prevent it collapsing whilst inhaling

Question 3

Journey of air our

Answer 3

Carbon dioxide diffuses from blood into

Question 4

Alveoli

Answer 4

Air sacks for the sites of gas exchange in lungs
Surrounded by capillaries where oxygen diffuses into deoxygenated blood and carbon dioxide into the alveoli

Question 5

Alveoli Adaptations

Answer 5

Huge surface area due to many alveoli
Thin walls
Very good blood supply = oxygenated blood rapidly removed to keep a steep concentration gradient

Question 6

Breathing

Answer 6

Increases rate of diffusion
By taking in fresh oxygen and removing co2
Keeping the concentration gradient high