Bitesize has changed! We're updating subjects as fast as we can. Visit our new site to find Bitesize guides and clips - and tell us what you think!
Print

Physical Education

The respiratory system

Page:

  1. 1
  2. 2
  3. 3
  1. Back
  2. Next

Inhaled and exhaled air

Inhaled [Inhaled: Breathed in. ] air contains:

  • more oxygen used to create energy
  • less carbon dioxide than…

Exhaled [Exhaled: Breathed out. ] air which contains:

  • more carbon dioxide produced as a waste product of energy production
  • less oxygen as it has been used in respiration

Gas exchange [Gas exchange: Oxygen passes through the capillary wall and into the tissues; carbon dioxide passes from the tissues into the blood. ] takes place by diffusion in the alveoli within the lungs. As a result the composition of inhaled and exhaled air is different.

Gas exchange

Gas% in inhaled air% in exhaled air
Oxygen2116
Carbon dioxide0.044
Nitrogen7979
NB These figures are approximate.

Page:

  1. 1
  2. 2
  3. 3
  1. Back
  2. Next

Back to Applied anatomy and physiology index

BBC © 2014 The BBC is not responsible for the content of external sites. Read more.

This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.