Geniculate ganglion

The geniculate ganglion (from Latin genu, for "knee") is a bilaterally paired special sense ganglion of the intermediate nerve component of the facial nerve (CN VII). It is situated within facial canal of the head.

It contains cell bodies of first-order unipolar sensory neurons which convey gustatory (taste) afferents from taste receptors of the anterior two-thirds of the tongue by way of the chorda tympani, and of the palate by way of the greater petrosal nerve, From the gangion, the proximal fibres proceed to the gustatory (i.e. superior/rostral) part of the solitary nucleus where they synapse with second-order neurons.

Anatomy

Structure

The geniculate ganglion is conical in shape. The greater petrosal nerve diverges from CNVII and the lesser petrosal nerve diverges from CN IX at the geniculate ganglion.

Relations

It is located close to the internal auditory meatus. It is covered superiorly by the petrous part of the temporal bone (which is sometimes absent over the ganglion).

Clinical significance

The geniculate ganglion is an important surgical landmark near the internal auditory meatus.

Herpes zoster oticus

The geniculate ganglion may become inflamed due herpes zoster virus virus infection. Swelling of the ganglion may result in facial palsy (Ramsay Hunt syndrome). The syndrome presents with intense pain in one ear that is followed by a vesicular rash around the ear canal.

Additional images

See also

• Ramsay Hunt syndrome type II

References

External links

• cranialnerves at The Anatomy Lesson by Wesley Norman (Georgetown University) (VII)
• lesson3 at The Anatomy Lesson by Wesley Norman (Georgetown University) (midearcavity)

1. Ramsay Hunt syndrome type 2
2. Facial nerve
3. Geniculate nucleus
4. Lateral geniculate nucleus
5. Greater petrosal nerve
6. Retinal ganglion cell
7. Intermediate nerve
8. Ramsay Hunt syndrome
9. Geniculate ganglionitis
10. Pseudounipolar neuron
11. Intrinsically photosensitive retinal ganglion cell
12. Cranial nerve ganglia
13. Optic nerve
14. Parasympathetic nervous system
15. Visual system
16. Lingual papillae
17. Cranial nerves
18. Receptive field
19. List of nerves of the human body
20. Facial nerve paralysis