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Equine Nervous System - Horse Anatomy (view source)
Revision as of 16:27, 21 November 2012
, 16:27, 21 November 2012→Glossopharyngeal nerve (IX)
====Glossopharyngeal nerve (IX)====
====Glossopharyngeal nerve (IX)====
The glossopharyngeal nerve is part of the group of cranial nerves responsible for innervation of structures derived from the branchial arches. This nerve innervates structures related to the third branchial arch. It is also part of a group, together with the vagus and accessory nerves, that passes through the '''jugular foramen''' which is termed the '''vagus group'''. The glossopharyngeal nerve has cell bodies that are referred to as '''nucleus ambiguus'''. The glossopharyngeal nerve originates from the '''medulla oblongata''' and has several branches including the '''pharyngeal nerve''', the '''lingual nerve''' and the '''tympanic branches'''.
The glossopharyngeal nerve is composed of many fibre types including '''general somatic efferent fibres''' that innervate the stylopharyngeus muscle; the '''general visceral afferent fibres''' that provide sensory information from the carotid body, the pharynx and the middle ear; the '''general visceral efferent fibres''' that provide parasympathetic innervation to the parotid and zygomatic salivary glands; the '''special visceral afferent fibres''' that provide taste caudal to the tongue and finally the '''general somatic afferent fibres''' that provide sensory information from the external ear. The '''lingual branch''' of the glossopharyngeal nerve provides '''general somatic afferent fibres''' and '''special visceral afferent fibres''' to the caudal 1/3 of the tongue.
On clinical examination, choking or dysphagia as a result of malfunctioning or absent pharyngeal reflexes would indicate a problem with the glossopharyngeal nerve.
====Vagus nerve (X)====
====Vagus nerve (X)====
====Accessory nerve (XI)====
====Accessory nerve (XI)====