The pharyngeal nerve emerges from the inferior ganglion of the vagus nerve on each side. It hooks around the internal carotid artery, between it and the internal jugular vein, to pass posteromedially to the posterior of the pharynx. Here it ramifies to join the pharyngeal plexus at the level of the middle constrictors of the pharynx.
In terms of its anatomical origin, the pharyngeal nerve is a branch of the vagus. However, it carries mainly nerve fibres from the accessory part of the cranial nerve which originate in the nucleus ambiguus of the medulla. There may also be a few sensory fibres to the sensory nucleus of the trigeminal nerve.
Through the pharyngeal plexus, the pharyngeal nerve supplies most of the motor fibres to the following muscles:
- levator palati
- superior pharyngeal constrictors
- middle pharyngeal constrictors
- inferior pharyngeal constrictors
- some striated muscle within the upper oesophagus