Exchanging substances

Question 1

What is the job of lungs and how do they do the job ?

Answer 1

to transfer oxygen to the blood and to remove waste co2 from it.
To do this the lungs contain millions of little air sacs called alveoli where gas exchange takes place

Question 2

What does the alveoli have and what are they specialised for ?

Answer 2

Specialised to maximise the diffusion of 02 and c02
They have :
- an enormous surface area
- a moist lining for dissolving gases
- very thin walls
- a good blood supply

Question 3

The inside of the small intestine is covered in ..
What do they do ?

Answer 3

millions and millions of these tint little projections called villi
They increase the SA in a big way so the digested food is absorbed much more quickly into the blood.

they have
- single layer of surface cells
- a very good blood supply to assist quick absorption