C2) Function of the respiratory system

Question 1

Gaseous exchange

Answer 1

Delivery of oxygen from the lungs to the bloodstream & the removal of carbon dioxide from tissues

Question 2

Inspiration- Breathing in

Answer 2

The external intercostal muscles contract to pull the ribcage up & out
Diaphragm contracts causing it to flatten
Chest cavity gets larger causing pressure in the lungs to fall
Air moves into the lungs from the higher outside pressure

Question 3

Expiration- Breathing out

Answer 3

The external intercostal muscles relax so the ribcage returns to normal
Internal intercostal muscles contract to pull the ribs in & down
Diaphragm relaxes pushing it up
The chest cavity gets smaller & so pressure in the lungs increases
Air flows out of the lungs

Question 4

Diffusion gradient

Answer 4

From a high concentration to a low concentration
To reach an equalibrium