- Humans have two lungs to perform respiration. The left lung has three lobes (parts), but the right lung consists of only two parts. Thus the left lung appears smaller and different when compared to the right lung. Due to such variation only, our left lung could accommodate the space needed for our heart.

- The basic function of a lung is to respire. The process of respiration is entirely different from breathing. Breathing just involves the intake of oxygen or exhaling the carbon dioxide. But lungs would supply the oxygen to the blood cells and would take away the excess of carbon dioxide from them.

- A cage of bones called rib cage would prevent our lungs from any external harm. This is the hard thing that we feel when we touch our heart. The rib cage also protects our kidneys and heart.

- Our lungs expand to intake the oxygen and contrast while they emit the carbon dioxide. A muscle beneath the lungs called 'Diaphragm' would help the muscles in the process. The Diaphragm also separates the lungs from the rest of the body.

- The food we take in and the air we inhale through nose would both go through the tube called Trachea! A part of the Trachea runs into the lungs and the other part extends to the stomach. This is the reason why we can breathe air through our mouth!

- The trachea turns into a tube called Bronchi as it enters the lungs. The Bronchi in turn splits into tiny tubes called 'Bronchioles'. As the end of each Bronchiole, numerous tiny sacks called 'Alveoli' were placed. Alveoli are the place where the actual respiration takes place! There are around 300-600 million Alveoli present in our lungs!

- Our lungs produce mucous to defend against the microbes that try to enter the lungs. However if excess mucus is clogged up in the lungs, it might be a symptom of underlying disease that range from Cold to Tuberculosis.

- Exercise is really good for our lungs. It would let them expand and contract at full extent. Besides, healthy habits like non-smoking and drinking plenty of fresh water would keep our lungs clean and healthy.