The larynx, or voice box, is the short tube of cartilage, ligaments, muscle and mucous membrane that connects the throat to the trachea. It guards the airway during swallowing and contains the vocal folds that produce the voice. In adults it lies at the level of the C3-C6 vertebrae and forms the Adam's apple at the front of the neck.
| Location | Anterior neck, below the hyoid bone and above the trachea, in front of the laryngopharynx, at about C3-C6 in adults (higher in infants). |
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| Parts |
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| Nerve Supply | Superior laryngeal nerve (internal branch sensory above the vocal folds, external branch to cricothyroid); Recurrent laryngeal nerve (motor to other intrinsic muscles, sensory below the vocal folds) |
| Blood Supply | Superior laryngeal artery (from the superior thyroid artery); Inferior laryngeal artery (from the inferior thyroid artery) |
| Venous drainage |
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| Lymphatic drainage |
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Protects the lower airway by closing during swallowing and triggering cough, regulates airflow, produces sound for speech (phonation), and allows breath-holding to stabilise the trunk during lifting and straining.
Closing the glottis against a forced breath out (the Valsalva manoeuvre) raises chest and abdominal pressure and helps brace the spine during heavy lifts, but sharply affects blood pressure. Hoarseness lasting more than about three weeks, especially in smokers, needs laryngoscopy to exclude cancer. Both recurrent laryngeal nerves supply most intrinsic muscles and are at risk in thyroid and chest surgery.
Usually squamous cell carcinoma, strongly linked to smoking and alcohol. Persistent hoarseness is the commonest early sign of glottic tumours.
Inflammation of the larynx, usually viral or from voice overuse, causing hoarseness or loss of voice. It typically settles within one to two weeks with voice rest.
Fracture of the laryngeal cartilages from a direct blow to the front of the neck, as in contact sports or road accidents. It can threaten the airway and needs urgent assessment.
