Kaplan Nursing Entrance Exam Practice 2025 – Comprehensive Prep

The function of the nose in the respiratory system primarily involves conditioning the inhaled air before it reaches the lungs. This conditioning involves adding moisture and warmth to the air, which is essential for protecting the delicate tissues of the respiratory tract and optimizing gas exchange.

When air is inhaled through the nostrils, it passes through the nasal passages where it is warmed by the blood vessels in the nasal lining and humidified by mucus secreted by the mucous membranes. This process helps prevent irritation and damage to the respiratory tract and ensures that the air is at a suitable temperature and humidity level when it arrives in the lungs, facilitating optimal oxygen absorption and carbon dioxide removal in the alveoli.

In contrast to other functions provided in the options, producing mucus, filtering carbon dioxide, and controlling breathing rate do play roles in the respiratory system; however, they are not the primary function of the nose itself. Mucus production is part of the overall defense mechanism of the respiratory system, filtering particles, but the primary role of the nose is more about conditioning air rather than mucus production, which occurs throughout the respiratory tract. The nose does not filter carbon dioxide; rather, it helps filter out dust and pathogens from inhaled air. Similarly, while the brain controls