Mammals

Respiratory System

Lungs

Description

Humans have mammalian lungs. They're like two big sponges that can fill with air. Just like a sponge can pick up lots of water, lungs can hold lots of air. Small air sacs called alveoli are where the blood picks up the oxygen from the air and carries it to the cells in our bodies.

Humans, like all mammals, are warm blooded, which means we keep our bodies at a constant temperature all the time. In Canada, during the winter we keep our houses warm, and during the summer we keep them cool. This takes energy, just like your body uses energy to keep you warm in the winter and cool in the summer. Remember that when your body needs energy, it uses oxygen to get the energy out of the food you eat. Mammalian lungs are very good at getting the oxygen out of the air, so our cells can get enough energy to keep doing their jobs!

Neat Stuff

When we exercise, our muscles are using up a lot of energy and our cells need to get more energy out of the food we've eaten. This takes lots of oxygen, so our lungs breathe in and out faster to get more oxygen out of the air! When you're resting, our cells aren't working as hard, so less energy is used and our breathing can slow down.