8 Interesting Facts About Lungs January 19, 2017 by Admin In Social Clips. 2.5 (17) 5. Oxygen only plays a small part in breathing. The air we breathe contains 21 percent oxygen, but our bodies only use 5 percent — the rest is exhaled. Study reveals the risk factors identified for bronchiectasis in COPD patients. Read more here. Print This Page How useful was this post? Click on a star to rate it! Submit Rating Average rating 2.5 / 5. Vote count: 17 No votes so far! Be the first to rate this post. As you found this post useful... Follow us on social media! We are sorry that this post was not useful for you! Let us improve this post! Tell us how we can improve this post? Submit Feedback Pages: 1 2 3 4 5 6 7 8