2.2 Gas exchange at alveoli and muscle

Question 1

How is gas exchanged at the alveoli?

Answer 1

blood stream contains large partial pressure of CO₂ and a small partial pressure of O₂. Alveoli contains high partial pressure of O₂ and small partial pressure of CO₂. Concentration gradient

Question 2

How else is oxygen drawn into muscle tissue?

Answer 2

by myoglobin and mitochondria

Question 3

What are three features of the alveoli that assist with gaseous exchange?

Answer 3

alveoli are one cell thick and therefore provide short diffusion distance
high concentration of blood capillaries to enable efficient gaseous exchange - large concentration gradient
Lots of air sacs creates large surface area to volume ratio - efficient gas exchange