McGraw Hill
Mc Graw Hill: The Circulatory and Respiratory Systems Post Test
An eleven question assessment covering the circulatory and respiratory systems of the human body. After the quiz is completed, answers can be checked with a click of the mouse.
US National Library of Medicine
Medline Plus: Gas Exchange
From MedlinePlus, a video tutorial featuring information on the gas-exchange process with accompanying text.
CK-12 Foundation
Ck 12: Biology: Processes of Breathing
[Free Registration/Login may be required to access all resource tools.] Outlines the four steps of respiration.
TED Talks
Ted: Ted Ed: Oxygen's Surprisingly Complex Journey Through Your Body
In the body, oxygen forms a vital role in the production of energy in most cells. Enda Butler tracks the surprisingly complex journey of oxygen through your body.