Question #686
Considering ganglia within the head, which of the following statements is correct?
There are a large number of ganglia in the head and neck. They are discrete collections of cell bodies located in the peripheral nervous system (discrete collections of cell bodies in the central nervous system are known as nuclei).
Sensory nerves have their cell bodies located in ganlia. Examples of these kind of ganglia include the dorsal root ganglia, the trigeminal ganglia and the geniculate ganglia.
There are four ganglia in the head that parasympathetic fibres synapse within:
- The pterygopalatine ganglion – located in the pterygopalatine fossa receiving fibres from the greater petrosal nerve via the vidian nerve, and sends post-ganglion fibres to the lacrimal gland via the zygomatic and lacrimal nerves.
- The ciliary ganglion – located between the optic nerve and lateral rectus muscle of the eye, receiving fibres from the oculomotor nerve and sending post-ganglionic fibres to the ciliary muscles and constrictor papillae via the short ciliary nerves.
- The otic ganglion – located in the infratemporal fossa receiving fibres from the lesser petrosal nerve and sends post-ganglionic fibres via the auriculotemporal nerve to the parotid gland.
- The submandibular ganglion – located adjacent to the submandibular gland and suspended on the lingual nerve. Receives fibres from the chorda tympani, that are carried by the lingual nerve, and sending post-ganglionic fibres to the submandibular and sublingual gland.
In addition to the parasympathetic fibres that synapse in these four ganglia, sympathetic fibres also pass through the ganglia, and in some cases taste fibres also pass through. Unlike the parasympathetic fibres they do not synapse.