The human respiratory system is responsible for bringing oxygen into the body and removing carbon dioxide. It consists of the following parts:
- Nose and mouth: where air enters the respiratory system
- Trachea: a tube that carries air to the lungs
- Bronchi: two branches of the trachea that lead to the lungs
- Lungs: where gas exchange takes place
- Diaphragm: a muscle that helps with breathing

Advantage of residual volume of air in lungs:
- Prevents lung collapse: The residual volume of air in the lungs prevents them from collapsing completely. This is important because it allows the lungs to maintain their shape and structure, making it easier to breathe in and out.
- Facilitates gas exchange: The residual volume of air in the lungs ensures that there is always some oxygen available for gas exchange, even during exhalation. This helps to maintain a constant supply of oxygen to the body tissues and removes carbon dioxide efficiently.
- Stabilizes lung function: The residual volume of air helps to stabilize lung function by keeping the alveoli (tiny air sacs in the lungs) open. This allows for efficient gas exchange and prevents the lungs from overworking.
In conclusion, the residual volume of air in the lungs plays a crucial role in maintaining lung function and overall respiratory health. It ensures that the lungs stay open, facilitates gas exchange, and helps prevent lung collapse.