The air passageway consists of the parts through which the outside air comes in the lungs and after the exchange of gases it goes out. This passage of air consists of the following parts.
The nose encloses the nasal cavity. It opens to the outside through the openings called the nostrils. The nasal cavity is divided into to two portions by a wall. Each portion is lined by fine hairs and mucous which filter the dust particles from the air. the mucous also moistens and warms the incoming air and keeps its temperature nearly equal to that of the body.
The nasal cavity opens into the Pharynx by means of two small openings called internal nostrils. Pharynxs a muscular passage and is common to both food and air. It extends to the opening of the oesophagus and the larynx. The air goes from the Pharynx into the larynx. We know that Glottis is a narrow opening at the floor of Pharynx which leads into larynx.
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