Daksh

So when you run 3 laps in a circle and stop you take a heavy breath right why does that happen? because you need oxygen. so when you breathe in, the oxygen goes to your nose, and in your nose there are small hair so when you breath in the dust also goes in so the small hair takes the dust and some dust does not get caught by the hair and it goes to the wind pipe also called trachea and it splits into 2 parts called bronchi the bronchi sends the oxygen into the lungs and near the lungs there are small sticky hairs and that takes the germs. and the right lung has three lobes as the left lung has two lobes and the left lung is little smaller than the another because the heart is there and in the lobes there are small spongy air sacs called alveoli where the exchange of oxygen and carbon dioxide happens the blood picks up the oxygen and let go off the carbon dioxide just beneath the lungs there is a dome - shaped muscle called diaphragm that contracts when you breathe in and expands when you breathe out.