What 3 things happen to the air you breathe before it reaches alveoli?

Before reaching the alveoli, the air you breathe undergoes several changes:

1. Filtration: The air is filtered by the nose hairs and mucus lining the respiratory tract. This process traps dust, pollen, and other particles, preventing them from entering the lower respiratory tract.

2. Warming and Humidification: The air is warmed and humidified as it passes through the nasal passages and pharynx. This helps to protect the delicate tissues of the lungs from drying out.

3. Gas Exchange: In the trachea, bronchi, and bronchioles, the air comes into contact with a network of blood vessels. Here, oxygen from the air diffuses into the bloodstream, while carbon dioxide diffuses from the bloodstream into the air.