There are a large number of odor sensing cells in the olfactory part above the nasal cavity, and the odor molecules in the air inhaled during breathing will be sensed after contacting the olfactory cells. In addition, the trigeminal nerve widely distributed in the ear mucosa also contributes to the feeling of taste.
When the air inhaled from the external nasal cavity passes through the uneven narrow nasal cavity, it will fully absorb the moisture of mucus secreted by mucous membrane, make its temperature close to body temperature, become moist air, and be sent to the lungs later. In addition, dust in the air will be adsorbed on nose hair and mucus, thus ensuring that clean air is sent to the lungs.
In addition, when people make sound, the soft flap can move freely, and part of the exhaled air enters the nasal cavity to resonate, thus making the sound louder.
In addition, the depth of the nose can be closed, so that air can not pass through the nose and make some clear sounds.