gas exchange

Question 1

what are the key properties of an efficient gas exchange system?

Answer 1

surface area- the bigger the surface area, more particles can be exchanged
thin layers: to minimise the diffusion distance
rich blood supply: to maintain a steep concentration gradient
moist surface: diffusion takes place with gases in solution

Question 2

what are the adaptations of the alveoli?

Answer 2

single layer of epithelial cells minimise the diffusion distances
large surface area: allows for fast diffusion
steep concentration gradient: blood is continuously flowing through the capillaries past the alveoli, exchanging gases