Corpus: Intermediate nerve
English: nervus intermedius, nerve of Wrisberg, glossopalatine nerve
1. Definition
The term intermediate nerve refers to the sensory and parasympathetic components of the 7th cranial nerve (facial nerve), which run separately from the motor fibres.
2. Anatomy
The nerve is called the "intermediate" because its fibers run "between" the 7th and 8th cranial nerves (vestibulocochlear nerve). It emerges from the cerebellopontine angle. The greater petrosal nerve branches off from the fibers of the nervus intermedius at the geniculate ganglion. The chorda tympani branches off later, before the nerve exits the base of the skull.
3. Innervation
The nervus intermedius conducts sensory information from the following areas:
- Skin of the external auditory canal
- Parts of the mucosa of the nasopharynx and the nasal cavity
It also carries sensory information from the taste receptors of the anterior two-thirds of the tongue, as well as the floor of the mouth and the soft palate.
The parasympathetic components of the nervus intermedius supply the submandibular and sublingual salivary glands, as well as the lacrimal glands.
4. Clinical relevance
Compression of the intermediate nerve by neighbouring vessels or tumours can trigger intermedius neuralgia.