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Equine Upper Respiratory Tract - Horse Anatomy (view source)
Revision as of 16:05, 18 November 2012
, 16:05, 18 November 2012→Pharynx
==Pharynx==
==Pharynx==
The three parts of the pharynx are the '''oropharynx''', '''laryngopharynx''' and '''nasal pharynx'''. The '''[[Soft Palate|soft palate]]''' separates the rostral part of the pharynx into the nasopharynx (dorsal) and oropharynx (ventral). The laryngopharynx is where these two compartments communicate, located in the caudal part of the pharynx.
*Oropharynx: Extends from the glossopalatine arch in the oral cavity to the base of the epiglottis.
*Nasopharynx: Forms part of the ventral nasal meatus through the choanae. It communicates with the ostia of the auditory tubes, auditory tubes and the guttural pouch.
*Laryngopharynx: Extends from the intrapharangeal opening to the oesophagus and the larynx.
During normal breathing, the [[Soft Palate|soft palate]] extends to the base of the epiglottis. The free apex of the rostral epiglottis lies dorsal to the [[Soft Palate|soft palate]]. This means horses are obligate nasal breathers and are unable to vomit. If horses do vomit, it is expelled through the nose.
===Pharyngeal Muscles===
The muscles are the ''tensor veli palatine'' and ''levator veli palatine''. The rostral pharyngeal constrictors are ''pterygopharyngeus'' and ''palatopharyngeus'', which arise from the base of the skull. The caudal pharyngeal constrictors are the ''thyropharyngeus'' and ''cricopharyngeaus'', which arise from the larynx. The only dilator of the pharynx is the ''stylopharyngeus caudalis''.
===Innervation===
The nervous supply comes from the pharyngeal branch of the vagus nerve ([[Cranial Nerves - Anatomy & Physiology|CN X]]) and from the cranial root of the accessory nerve ([[Cranial Nerves - Anatomy & Physiology|CN XI]]). The stylopharyngeous muscle is innervated by the accessory nerve ([[Cranial Nerves - Anatomy & Physiology|CN XI]]). The glossopharyngeal nerve ([[Cranial Nerves - Anatomy & Physiology|CN IX]]) supplies taste to the pharynx.
==Trachea==
==Trachea==
==References==
==References==