small size - each of the alveoli is a small sphere about 300 μm in diameter, giving it a larger surface area to volume ratio than larger structures number - there are around 700 million alveoli ...

Diseases that can affect these airways include: Your airways branch into tiny tubes (bronchioles) that end in clusters of air sacs called alveoli ... on your lung's surface slide along the ...

The cells in the body need oxygen to release energy from food efficiently by carrying out aerobic respiration. A waste product of aerobic respiration is carbon dioxide. The layer of moisture in ...