throat
Meaning of throat: The one place where the routes for breathing and swallowing share a corridor, which is why a swallow has to be so precisely timed.
Definition of throat
The throat is the passage at the back of the mouth and nose that carries both air and food toward the chest. In everyday use it covers the pharynx, the muscular tube running from behind the nose down to the voice box, and often the voice box itself. At its lower end the pathway divides into the windpipe in front and the food pipe behind.
What are its parts?
| Region | Position | Contains |
|---|---|---|
| Nasopharynx | Behind the nose | Adenoids, and the openings of the tubes to the middle ear |
| Oropharynx | Behind the mouth | Tonsils, the back third of the tongue, the soft palate |
| Hypopharynx | The lowest section | Leads into the food pipe and wraps around the voice box |
Those three sections together make up the pharynx. The voice box sits in front of the lowest section and is usually included when people talk about the throat, although anatomists treat it as a separate structure.
How does swallowing avoid the airway?
Air and food cross paths here, so the timing has to be exact. As a swallow begins, the soft palate lifts to seal off the nose. The voice box rises and moves forward, and a flap of cartilage folds back across its opening. The vocal cords close. Breathing pauses for a moment. Only then do the muscles of the pharynx squeeze the food downward into the esophagus, while a ring of muscle at its top relaxes to let it through. When any step in that sequence fails, food or liquid enters the trachea instead, which causes choking or, in someone with a weak cough, pneumonia.
What else does it do?
The throat shapes sound. The voice box produces the tone, and the space above it acts as a resonating chamber giving a voice its individual quality, which is why a voice changes when the throat is swollen. Rings of lymphoid tissue, the tonsils and adenoids, sit at the entrance and sample what arrives from mouth and nose, a useful job in early childhood that explains why they enlarge then and shrink later. The tubes to the middle ear open into the upper section and equalize pressure behind the eardrum.
What commonly goes wrong?
Sore throat from a viral infection is the everyday complaint, and streptococcal infection is the bacterial cause that gets looked for. Swelling from allergy can narrow the passage quickly. Persistent hoarseness, difficulty swallowing or a lump felt in the neck are the features prompting closer examination, since tobacco, alcohol and human papillomavirus are established causes of cancer in this region.
Also known as
Used in a sentence
The examination noted redness of the throat with enlarged tonsils and tender cervical nodes.
Good to know
The throat carries air and food along a shared route, so a failure in the timing of a swallow sends material into the airway, and repeated small aspirations cause pneumonia in someone with a weak cough.