Pharynx and gutteral pouch Flashcards
what is the pharynx
- common cavity for food and ingesta
- oral cavity ventrally with esophagus dorsally
- nasal cavity dorsally with larynx and trachea ventrally
what are the margins of nasopharynx
ventral: soft palate
rostral: choanae
caudal laryngopharynx
lateral and dorsal pharyngeal wall
what is the nasopharyngeal recess
caudodorsal extension of the nasopharynx
- found in most ungulates
- blind ending
- no purpose -> ET tube or scope can get stuck
what are the margins of the oropharynx
dorsal: soft palate
ventral: tongue
rostral: oral cavity
caudal: laryngopharynx
what are the margins of the laryngopharynx
rostral: free tip of the soft palate
caudal: larynx and opening of esophagus
lateral and dorsal: pharyngeal wall
what is the soft palate, what muscles does it consist of
- divides the pharynx
- flexible muscular structure
- palatinus muscle (within main body) shortens the palate
- tensor veli palatini muscle (within rostral side wall) causes lateral traction and thus tension
- levator veli palatini (within rostral side wall) raises palate during swallowing and mouth breathing
- innervated by mandibular branch of trigeminal nerve
what is the pharyngeal wall
- made of striated muscles for constricting and shortening (rostral=palatopharyngeal, middle=hypopharyngeal and caudal=thyropharyngeal) all insert onto the roof of the pharynx (dorsal and lateral arches). important for passage of food and dilation (via stylophayngeus caudalis)
all innervated by vagus and hypoglassal nerve
describe the process of swallowing
- soft palate elevated to obstruct nasopharynx and open oropharynx
- palatopharyngeal arch constricts
- hyoid apparatus pulls larynx forward
- epiglottis flips back to cover tracheal opening
- tongue pushes food into esophagus
what is the guttural pouch
- auditory tube running from nasopharynx to middle ear in all species
- guttural pouch is large diverticulum of the auditory tube in horses
what are the margins of the guttural pouvh
dorsal base of skull
ventral: laryngopharynx and esophagus
lateral: skin
medial: septum
what is the function of the guttural pouch
possibly to cool blood to brain (no obvious other functions)
how can the guttural pouch be entered with a scope
through the slits into the nasopharynx (also where it drains)
discuss the structures within the guttural pouch
- stylohyoid bone (divides into lateral and medial compartments)
- cranial nerves (glossopharyngeal, vagus, hypoglossal)
- blood vessels (internal and external carotid artery)
- longus capitus muscle
- pharyngeal lymph nodes
list and describe some diseases of the guttural pouch
bacterial
- strangles caused by strep. equi
fungal
- mycosis
- signs depend on location of plaques
- plaque can eat into artery and cause animal to bleed out or cause neurological disease if over nerve
how do you access the guttural pouch surgically
via viborg’s triangle
