The upper airway runs from the nose and mouth down to the larynx. It conditions incoming air and shares the throat with the path for food.
Nose and nasal cavity
Hairs, mucus and a rich blood supply filter, warm and humidify air before it reaches the lungs. The turbinates make the air swirl so particles stick to the mucus, and the many blood vessels explain why nosebleeds are common.
Pharynx
The throat has three parts: the nasopharynx behind the nose, the oropharynx behind the mouth and the laryngopharynx above the larynx and esophagus. The tonsils and adenoids in its walls are lymphoid tissue that samples what we breathe and swallow.
A shared path with food
Air and food cross in the pharynx. During swallowing the soft palate seals off the nose and the epiglottis tips over the larynx, so food goes into the esophagus.
The tongue and soft tissues
In an unconscious patient the muscles relax and the tongue and soft palate fall back against the back of the throat. This is the most common cause of airway obstruction and causes snoring or gurgling sounds.
At the bedside
A head tilt with chin lift, or a jaw thrust when spinal injury is possible, lifts the tongue off the back of the throat. If that is not enough, an oral or nasal airway holds the tongue forward.
Related guides
Written by Making Synapses. Topic reference: OpenStax, Anatomy and Physiology 2e (no text adapted).