Sinuses and Horn Flashcards
What are paranasal sinuses
Air filled extensions of the nasal cavity that invaginate into bone
What are paranasal sinuses innervated by
Opthalmic and maxillary branches of the trigeminal nerve
What sinuses do all species have
Frontal and maxillary sinuses
What are the functions of sinuses
- Resonating cavities (voice)
- Insulation/ cooling (brain)
- Light weight construction
- Increased insertion surfaces, space for teeth
What does the frontal sinus system consist of in all species
One or more spaces within the bones at the border between the nasal and cranial cavities
Where does the maxillary sinus system occupy in all species
The caudolateral part of the upper jaw, above the caudal cheek teeth (molars and premolars)
Where does the maxillary sinuses drain into in most species? Why is this drainage difficult?
- Into the middle meatus
- Drainage goes against gravity
How many compartments is the frontal sinus system made up of in
- Dogs
- Cattle
- Pigs
Dogs= 3 Cattle= 5 Pigs= 1 extensive cavity
Where does the frontal sinus drain into in most species
The ethmoidal region
How many individual paranasal sinuses are there in horses
7
What common structure do all paranasal sinuses drain via in horses
The ostium/ drainage angle
What are the groups that the paranasal sinuses in horses are split into
- Caudal paranasal sinuses (5)
- Rostral paranasal sinuses (2)
What are the 5 caudal paranasal sinuses in horses
- Caudal maxillary sinus
- Dorsal conchal sinus
- Ethmoidal sinus
- Frontal sinus
- Sphenopalatine sinus
What are the 2 rostral paranasal sinuses in horses
- Rostral maxillary sinus
- Ventral conchal sinus
Where is the infraorbital sinus located in birds
Under the skin rostroventral to the eye (triangular cavity)
Which sinus system does the nasolacrimal duct run through
Maxillary sinus system
Why are horses and ruminants more likely to get maxillary sinus infections compared to domestic species
Due to them having continuously erupting teeth
Which sinus is located next to the horn in cattle?
Why is this relevant?
- Frontal sinus
- During dehorning in adults the sinus is exposed resulting in predisposition to infection and nasal discharge
Where does the majority of the innervation of horns arise from
Trigeminal nerve
As well as the trigeminal nerve, what nerve innervates the horn in all animals
Cornual nerve
What nerves need to be blocked when dehorning calves
Corneal nerve
What nerves need to be blocked when dehorning adult cattle
- Corneal nerve
- corneal branch of infratrochlear nerve
- May also need to block region caudal to horn
Why do you need to be careful when dehorning goat kids
Frontal sinus is very small and excess heat can damage the brain
What arteries supply the horn in ruminants
- Corneal artery
- Which is a branch of superficial temporal artery
- Which is a branch of maxillary artery
What does unilateral nasal discharge usually represent
- Upper respiratory tract infection (bacterial or fungal)
- Nasal disease
- Sinus disease= sinuses drain into nasal cavities
What does bilateral nasal discharge usually mean
- bilateral upper airway disease
- lower airway disease- caudal to the pharynx/larynx
