Question

The human respiratory tract contains a lot of moisture. The alveoli have to be kept moist for gas exchange to occur. The airways also have to be moist to moisten the air before it reaches the alveoli. Some of this moisture is lost when we exhale. How is this moisture replenished? Which parts of the nervous system make sure that the respiratory tract is always kept moist?

Answer 1

The moisture in the respiratory tract is replenished through the process of warming and humidifying the air as it passes through the nasal cavity. The respiratory system also employs the mucociliary escalator to remove particles and pathogens from the airways.

Step-by-step explanation:

The moisture in the respiratory tract is replenished through the process of warming and humidifying the air as it passes through the nasal cavity. The nasal cavity contains mucous membranes that produce mucus to seal the tissues from direct contact with air. This mucus is high in water content, and as the air crosses these surfaces, it picks up water, effectively moisturizing the airways. Furthermore, the respiratory system utilizes a protective mechanism called the mucociliary escalator, where tiny hair-like structures called cilia move the mucus along the respiratory tract to remove particles and pathogens.