PATHOLOGY

Detailed explanation-1: -The major function of the upper airway is to air-condition the inspirate. It is not essential to breathe through the nose to do this, and the mouth will make a fairly good job of warming and humidifying inhaled air before it reaches the larynx.

Detailed explanation-2: -The mucus traps smaller particles like pollen or smoke. Hairlike structures called cilia line the mucous membrane and move the particles trapped in the mucus out of the nose. Inhaled air is moistened, warmed, and cleansed by the tissue that lines the nasal cavity.