Question: How do we breath

Joanna Barstow answered on 14 Nov 2019:

We breathe when the muscles in our chest and abdomen contract and relax. When we breath in, the big muscle beneath our lungs (the diaphragm) pulls downwards, and the muscles in our chest cause our ribcages to expand. This creates suction that pulls air into our lungs. When we breath out, those muscles relax and our chest compresses, which forces air out again. While the air is in our lungs, oxygen is removed and and carbon dioxide added.