The glossopharyngeal, vagus and cranial accessory nerves (CN IX, X, XI) can be considered as a group, passing through the jugular foramen, and are commonly damaged together. Jointly, they supply:

• motor innervation to the pharynx and larynx (CN X, joined by fibres from the cranial root of XI)
• parasympathetic supply to the parotid gland (CN IX) and thoracic and abdominal viscera (CN X)
• taste from the posterior third of the tongue and arterial chemo and baroreceptors (CN IX, X)
• somatic sensory innervation of the oropharynx and posterior tongue (CN IX), the larynx (CN X) and part of the middle ear, external acoustic meatus and external ear (CN IX, X).

CLINICAL CORNER

CN IX and X function can be assessed via the aversive gag reflex, even in an unconscious patient. Brisk stimulation of the posterior part of the tongue or oropharynx e.g. with a wooden spatula (unpleasant) activates afferents in CN IX provoking a reflex gag via motor fibres in CN X (which join the cranial XI).

Inflammation in the oropharynx (e.g. tonsillitis) can produce earache by referred pain (through innervation of both the middle ear and oropharynx by IX).

The vagus nerve is crucial for swallowing and can be assessed by observing the uvula (which should move vertically up and down when a patient says ‘aah’) or effects on speech (laryngeal function).