Exchanging Substances Flashcards
Where does gas exchange happen?
In the lungs.
What is the job of the lungs?
To transfer oxygen to the blood and to remove waste carbon dioxide from it.
How is the job of the lungs performed?
The lungs contain millions of air sacs called alveoli where gas exchange takes place.
What is alveoli specialised for?
To maximise the diffusion of oxygen and carbon dioxide.
How is alveoli adapted for gas exchange?
Enormous surface area
Moist lining for dissolving gases
Very thin walls
Good blood supply
What is the inside of the small intestine covered in?
Millions and millions of tiny little projections called villi.
What is a good thing about villi?
It increases surface area in a big way so that digested food is absorbed way more quickly into the blood.
What does villi have?
Single layer of surface cells
Very good blood supply to assist quick absorption
