==Key Stage 3==
[[File:Curiscope.png|right|300px|link=https://www.amazon.co.uk/gp/product/B074SW2M5N/ref=as_li_tl?ie=UTF8&tag=nrjc-21&camp=1634&creative=6738&linkCode=as2&creativeASIN=B074SW2M5N&linkId=61328e70ff8da279e84c71cf4ab0764f|thumb|Find out more about '''alveoli''' and internal structures with the Curiscope t-shirt and app.]]
[[File:AirSacs.png|right|300px|thumb|A [[diagram]] showing several [[alveoli]] and the [[Capillary|capillaries]] supplying them with [[blood]].]]
===Meaning===