Exhaled air vs inhaled air

//Exhaled air vs inhaled air

Exhaled air vs inhaled air

Air sacs. Image credit MediaWiki

Air sacs. Image credit MediaWiki

ZIMSEC O Level Integrated Science Notes:Exhaled air vs inhaled air

  • Air which enters the lungs (inhaled air) is different in several regards to air that is passed out (exhaled air)
  • Exhaled air contains less oxygen and more carbon dioxide.
  • It is also warmer and more moist.
ComponentInhaled (normal) areaExhaled air
Carbon dioxiode0.034
Water vapour approximately6higher
  • Nitrogen is not absorbed by plants or animals.
  • Inhaled air has more oxygen and less carbon dioxide when compared to exhaled air.
An air sac. Image credit wordpress.com

An air sac. Image credit wordpress.com

  • The composition of inhaled air changes in the alveoli.
  • This is where gas exchange takes place.
  • Each alveolus is a microscopic structure with capillaries .
  • The air in the alveoli has more oxygen than the blood around them.
  • The oxygen diffuses into the blood.
  • There is more carbon dioxide in the blood than in the alveoli so it diffuses from the blood into the air sacs.
  • This two way diffusion is called gas exchange.
  • This happens in millions of air sacs every minute of everyday.
  • The breathing process makes sure that there is a higher concentration of oxygen in the air sacs that in the blood.
  • This means that oxygen will always diffuse into the blood and carbon dioxide outside the blood.

To access more topics go to the Integrated Science Notes page.

By | 2017-01-17T11:17:58+00:00 August 25th, 2015|Uncategorized|1 Comment

About the Author:

He holds an Honours in Accountancy degree from the University of Zimbabwe. He is passionate about technology and its practical application in today's world.

One Comment

  1. isabelle January 31, 2018 at 5:47 pm - Reply

    this is so helful

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