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Diseases of the nasal cavity and sinuses (view source)
Revision as of 20:56, 29 November 2006
, 20:56, 29 November 2006→Functional anatomy
**Blood vessels, lymphatics and nerves
**Blood vessels, lymphatics and nerves
***Very rich blood supply to nasal mucosa
***Very rich blood supply to nasal mucosa
*Nasal chambers and turbinates
**Scrolls of turbinate bone
**Arrangements vary with species
*Nasal septum
**Full length of nasal chamber in horses
***2 openings into pharynx
**Partial length in other species
***Single opening into pharynx
*Sinuses
**Size, arrangement and number vary with species
**Poorly developed in carnivores
***Poor communication of frontal sinus in cats with nasal cavity
****Predisposed to frontal sinus bacterial infections
***Maxillary sinus opening very large - 'maxillary recess'
****Maxillary sinus infections very uncommon in carnivores
***Highly developed in horses
***Highly developed in horses
***Slit-like, high openings in horses
***Predisposed to bacterial infections
***Cheek teeth embedded within the maxillary sinuses
***Maxillary sinusitis secondary to tooth root abscesses
*Guttural pouch
**Horses
***Diverticulum of the eustachian tube with a thin slit-like opening at the rostroventral aspect into the pharynx.
***Mucous secretions drain out of the pouch when the horse lowers its head
***Lined by respiratory epithelium
***Bordered by glossopharyngeal, vagus, accessory and hypoglossal nerves; sympathetic trunk; internal and external carotid arteries
**Pathology
***Mycotic infections eg: Aspergillus fumigatus
****Bacterial infections eg: Streptococcus equi var. equi ('Strangles') or S.equi var zooepidemicus
****Bacterial infections eg: Streptococcus equi var. equi ('Strangles') or S.equi var zooepidemicus
***Tympany - associated with dysfunction of the pharyngotubal opening resulting from thickening (oedema, inflammation) or obstruction by a mucosal fold (eg: foals)
==Defense mechanisms==
==Defense mechanisms==