Breathing, a non-stop process happening in all living system. Ever wondered how it happens? How many organs are involved? Yes, we all know it is the lungs that help us to breath. But is it only lungs? Does all living organism have lungs? Well, the questions are endless. In humans, it is the lungs along with the nasal cavity, trachea, bronchi, alveoli, diaphragm that constitutes the respiratory system.

Lungs are spongy muscular organ situated in the thoracic cavity, near the backbone on either side of the heart. The lungs are protected in a bony cage, known as ribcage. Respiration starts with breathing. We breathe in air, through our nostrils. When we breathe, air enters into the nasal cavity through our nostrils, passes through the trachea into bronchi, through bronchioles enters the alveoli. It is in the alveoli where gaseous exchange takes place. Alveoli are filled with minute blood vessels called capillaries. The air enters the capillaries and into the bloodstream. It is then circulated to the entire body.

When we inhale, the diaphragm contracts and move downwards, creating space in the thoracic cavity for the lungs to expand to take in air efficiently. Similarly, when we exhale the diaphragm relaxes and moves back to its domelike shape forcing air to move out of the lungs. This air enters the alveoli, through bronchioles via bronchi into the trachea is exhaled out through our nostrils.