The respiratory system is the structure in the human body which allows us to breathe. It brings oxygen into our body and removes carbon dioxide out of our body.

When we breathe in (inhale) through our nose and mouth, air travels down our trachea (windpipe) and into our lungs through the left and right bronchi. Each bronchus splits into smaller bronchioles and then leads to small sacs called alveoli.

It is in the alveoli that the oxygen-rich air we have inhaled is absorbed into our blood. In the blood, the oxygen is carried to the heart and is then pumped to the trillions of cells throughout our body. Our cells use the oxygen to make energy and then release carbon dioxide (CO2) as a waste product, which is removed from the body as we exhale.

The respiratory system is made up of 5 main parts:

• Nose
• Mouth
• Trachea (windpipe)
• Lungs
• Diaphragm

The lungs are made up of 3 main parts:

• Bronchus (right & left)
• Bronchioles
• Alveoli