Name four parts of the respiratory system in order that air comes into the body, and describe the role it plays in respiration.

Nasal Cavity: The first part of the respiratory system is the nasal cavity. When we inhale, air enters the body through the nose. The nasal cavity filters, warms, and humidifies the air, preparing it for the lower respiratory tract.

Trachea: The air then travels down the trachea, also known as the windpipe. The trachea serves as a passageway for air between the nasal cavity and the lungs. It is lined with cilia that trap and move particles out of the airway, keeping the path to the lungs clear.

Bronchi: The trachea splits into two bronchi (one for each lung). The bronchi further branch out into smaller tubes called bronchioles. These tubes distribute the air evenly throughout the lungs.

Lungs: Finally, the air reaches the lungs. The lungs are the primary organs of the respiratory system. They are responsible for the exchange of gases. Oxygen from the inhaled air is passed into the bloodstream, and carbon dioxide, a waste product of metabolism, is removed from the blood and exhaled. This process is known as gas exchange and is essential for respiration.