The respiratory system is the collection of organs and structures in the body responsible for breathing and gas exchange. Its primary function is to bring oxygen into the body and remove carbon dioxide, a waste product of cellular metabolism. This system includes the lungs, airways (such as the nose, mouth, trachea, bronchi, and bronchioles), the diaphragm, and associated muscles and blood vessels. Key components of the respiratory system are divided into two parts:

• Upper respiratory tract: Includes the nose, nasal cavity, sinuses, mouth, throat (pharynx), and voice box (larynx). This part warms, moistens, and filters the air we breathe.
• Lower respiratory tract: Comprises the trachea, bronchi, bronchioles, lungs, alveoli (tiny air sacs where gas exchange occurs), and diaphragm.

The respiratory system works closely with the circulatory system to deliver oxygen to body cells and remove carbon dioxide from the bloodstream. Breathing involves inhaling oxygen-rich air into the lungs and exhaling carbon dioxide- rich air out of the body. The diaphragm and intercostal muscles facilitate this process by changing the pressure in the chest cavity to move air in and out of the lungs. Besides gas exchange, the respiratory system also helps protect the body from harmful particles, allows us to smell, and enables speech through the vocal cords in the larynx. Overall, the respiratory system is essential for sustaining life by ensuring that oxygen reaches the cells and carbon dioxide is efficiently expelled