Your respiratory system is the organs and structures in your body that allow you to breathe. It includes your lungs, nose, mouth and the tubelike structures (airways) that connect them. You also have muscles and blood vessels that support your respiratory system, and ribs to protect it. These parts work together to bring oxygen into your body when you inhale and get rid of carbon dioxide when you exhale.
The main function of your respiratory system is to pull in oxygen for your body’s cells and get rid of carbon dioxide, a waste product. You do this by breathing in and out and through gas exchange between the small air sacs of your lungs (alveoli) and the blood vessels running nearby. Your respiratory system also:
Warms and adds moisture to the air you breathe in. Your respiratory system warms the air to match your body temperature. It moisturizes the air to bring it to the humidity level your body needs.
Protects your body from particles you breathe in. Parts of your respiratory system can block harmful germs and irritants from getting in — or push them out if they do get in.
Allows you to talk. Air vibrates your vocal cords, which makes sounds.
Helps you smell. Breathing in air moves its molecules past your olfactory nerve, which sends messages to your brain about the way something smells.
Balances level of acidity in your body. Too much carbon dioxide lowers your blood’s pH, making it acidic. By removing carbon dioxide, your respiratory system helps maintain the acid-base balance in your body.