**3.3 Distribution in the territory of the glossopharyngeal nerve**

Most research have not found typical muscle spindles in the muscles innervated by the glossopharyngeal nerve although they are present in the human *palatoglossus* muscle [48].

Regarding the pharyngeal muscles, typical muscle spindles were never found with the exception of the *constrictor pharyngis inferior* of the crab-eating monkey (*Macaca irus*) [62]. Nevertheless, human pharyngeal muscles are richly innervated. In particular, the *constrictor pharyngis superior* and muscle *constrictor pharyngis inferior* (innervated by branches of the pharyngeal plexus, derived from the glossopharyngeal and vagal nerves, and a small contribution of facial nerve; [63]) contain type II and III putative proprioceptors and isolated nerve fibers that display immunoreactivity for mechanoproteins (**Table 1**) [43].
