The journey of the air to the lungs

Air enters the body through either the mouth or the nose.
It is better to breath through your nose as the hairs in your nose filter the air, it is warmed because the membrane in close contact with blood vessels, and moistened by the mucus in the naval cavity
From the nose the air goes to the trachea. - rings of cartilage around the trachea stop it from collapsing especially when food is swallowed.
In the thorax the trachea divides into 2 main different branches - bronci
These divide into broncus which when in the lung divide into many smaller branches called bronchiole.
At the of the bronchiole are tiny air sacs called alvioli
This is where diffusion into the blood takes place.

	Created by younje2011 almost 11 years ago

edexel igcse Biology Note on Gas Exchange in the body, created by younje2011 on 15/01/2014.

Gas Exchange in the body