1
Q
where does gas exchange happen
A
lungs
2
Q
what is the lungs job
A
transfer oxygen into the blood
diffuse carbon dioxide from the blood
3
Q
how are the alveoli adapted to maximise diffusion
A
large surface area
moist lining
thin walls
good blood supply
4
Q
where are villi located
A
small intestine
5
Q
why do villi increase the surface area
A
so digested food is absorbed into the blood quicker
6
Q
how are villi adapted
A
single layer of surface cells
good blood supply
large surface area
