KS3 Science · Biology
Breathing and gas exchange
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Key words
Breathing Moving air into and out of the lungs
Gas exchange Taking in one gas and giving out another
Trachea The windpipe: carries air from the nose and mouth towards the lungs
Bronchi Two tubes that carry air from the trachea into the lungs
Bronchioles Small tubes inside the lungs
Alveoli Tiny air sacs at the ends of the bronchioles
Diaphragm A sheet of muscle underneath the lungs
Ribs Bones that make a cage around the lungs
Intercostal muscles The muscles between the ribs
Diffusion Particles spreading from a high concentration to a low concentration
Lung volume A measure of the amount of air breathed in or out
Breathing rate The number of breaths taken in one minute
Respiration A chemical reaction in cells that releases energy
Asthma A condition in which the airways sometimes get narrower
Tar The sticky substance in tobacco smoke that causes cancer
Nicotine The addictive drug in tobacco smoke
Carbon monoxide A poisonous gas that takes the place of oxygen in the blood
Stomata Tiny pores in a leaf that let gases in and out