The structure of the lungs works like this. We breath in through the mouth or nose and oxygen passes through your trachea. After that, the trachea seperates into two bronchi which lead to your right lung and left lung. Your right lung is seperated into three parts. Your left lung is separated into two parts instead of three parts because it shares space with the heart. The oxygen travels through the left and right lungs through many bronchiolies until it reaches the alveoli where it goes to the rest of the body through the bloodsteam.

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