4.3 Exchange Of Gases In The Lungs Flashcards
0
Q
Why do they need a large surface area to volume ratio?
A
To speed up the rate of exchange
1
Q
What are the 5 essential features of an exchange surface?
A
Large surface area to volume ratio Very thin Partially permeable Movement of the environmental medium Movement of the internal medium
2
Q
Why do they need to be very thin?
A
To keep diffusion pathway short
3
Q
Why does it need to be partially permeable?
A
To allow selected materials to diffuse easily
4
Q
What is Fick’s law?
A
Diffusion is proportional to: surface area x difference in concentration divided by length of diffusion pathway
5
Q
How many alveoli are there in each human lung?
A
300 million
