equine head and neck Flashcards
Motor innervation to the face
CN VII - facial
Sensory innervation to the head
CN V - trigeminal (V1, V2, V3)
where to take the pulse in equine head?
facial artery
THE GUTTURAL POUCHES ARE ASSOCIATED WITH THE
Internal Carotid, External Carotid, & Maxillary Arteries
what cranial nerves are associated with the guttral pouches?
Cranial Nerves IX, X, XI and XII
The function of Viborg’s triangle:
a place for the surgical incision to locate and open an infected diverticulum of the auditory tube (AKA GUTTRAL POUCH)
in the horse the frontal sinus drains into ????, not directly into the nasal cavity.
the caudal maxillary sinus
CN VII (Hypoglossal) supplies what?
Rrostal 2/3rd of the tongue
The parotid gland occupies what space?
It occupies the space between the caudal border of the mandible, the wing of the atlas, and the base of the ear, and ventrally it extends to
the linguofacial vein
What blood supplies accompanies the parotod duct
facial artery and facial vein
Where does the parotod duct drain into?
duct opens into the oral vestibule opposite of the 2nd or 3rd upper check tooth
Where does the mandibular duct drain in to?
passes onto the deep surface of the mylohyoideus where it follows the medial aspect of the sublingual gland to the sublingual caruncle on the floor of the mouth a few cm caudal to the incisors.
Muscles of mastication are innverated by what CN?
Mandibular (V3)
what includes the muscles mastication?
pterygoideus mm, massester, temporalis
Muscles of mastication are innverated by what CN?
Mandibular (V3) motor branch
Digastricus receives innervation from what CN?
Facial nerve
Swallowing mechanism in horses:
In swallowing the epiglottis, sliding out from the intrapharyngeal ostium, by its retroflexion closes the entrance to the larynx. By elevating the dorsum of the tongue, the bolus passes across the laryngeal entrance into the esophagus. A false passage into the nasal pharynx is prevented by elevation of the soft palate.
Swallowing mechanism in horses:
In swallowing, the bolus of food in the oral cavity, the bolus pushes the soft palate up, pushes the epiglottis back, runs along the rostal border of epiglottis to get injected into the esophagus, sliding out from the intrapharyngeal ostium, by its retroflexion closes the entrance to the larynx. By elevating the dorsum of the tongue, the bolus passes across the laryngeal entrance into the esophagus. A false passage into the nasal pharynx is prevented by elevation of the soft palate.
Damage to cranial nerve ____ results additionally in partial loss of the sensory and motor functions of the pharynx.
CN X - VAGUS
If the ____ cranial nerve is paralyzed, the lingual muscles are involved. The tongue droops from the mouth and cannot be retracted into the oral cavity.
XII - hypoglossal
Viborg’s triangle location (borders)
Its borders are dorsally the tendon of the sternomandibular muscle (sternocephalicus muscle), rostrally the cervical border of the mandible and ventrally the linguofacial vein.
Viborg’s triangle location (borders)
Its borders are dorsally the tendon of the sternomandibular muscle (sternocephalicus muscle), rostrally the cervical border of the mandible and ventrally the linguofacial vein.
CN XII function:
It supplies the motor innervation to all extrinsic and instrinsic muscles of the tongue
masseter, pterygoid, and temporalis muscles, and rostral part of the digastric muscle are innverated by which CN?
CN V - MANDIBULAR BRANCH
safe entry into the maxillary sinus
-line from facial crest to the medial canthus of the eye for safe entry into maxillary sinuses
safe entry into the maxillary sinus to avoid infraorbital nerve
- apex of the nasoincisive notch –> line from facial crest –> medial canthus of the eye for safe entry into maxillary sinuses (use the straight line as your dorsal border)
What two structures are you trying to avoid when trying to access the maxillary sinus?
the nasolacrimal duct and the infraorbital nerve
What are the dorsal boundaries of the guttural pouches?
base of the skull and atlas.
What are the ventral boundaries of the guttural pouches?
are the pharynx and the commencement of the esophagus.
What are the lateral boundaries of the guttural pouches?
pterygoid muscles and the parotid and mandibular salivary glands.
What are the medial boundaries of the guttural pouches?
longus capitis muscles and the septum which separates the two medial compartments.
What are the important anatomic features and structures associated with the guttural pouches
The stylohyoid bone, The medial retropharyngeal lymph node, AND Cranial nerves IX, X and XI
Sphincter of the mouth
obicularis oris
sphincter of the eye
orbicualris oculi
what muscle closes the horses lips?
obicularis oris
what muscle closes the horses eye
orbicularis oculi
what cranial nerve is most superficial on the face?
facial nerve – right under the cheek
Where does the facial nerve come from?
facial nerve comes right out of the skull and through the parotid gland
what happens if something happens to the superficial CN VII (facial)
hemi paralysis on one side of the face
infraoribital nerve is an extension of the ____ nerve
maxillary
2 places to take a pulse on the face?
transverse facial artery and the facial artery
2 places to take a pulse on the face?
transverse facial artery and the facial artery
nerve supply to the maxilla?
maxillary nerve
what nerve comes out of the foramen ovale
mandibular nerve
What nerve comes out of the infraorbital canal ???
maxillary nerve
what innervates the rostal 2/3rds of the tongue
lingual nerve
innervation of the teeth(roots)
V3 —> inferior alveolar nerve
what does the inferior alveolar nerve turn into?
mental nerve that comes out of mental foramen
Innervation of the teeth of the maxilla?
maxillary nerve (V2)
what does the maxillary nerve terminate into?
infraorbital nerve
motor nerve of the eyelid
facial nerve branch auriculopalpebral
sensory nerve of the eyelid
supraorbital nerve from V1
T/F cows don’t have a supraorbital nerve
TRUE - cornual nerve
what nerve desensitizes the area around the base of the horn in cattle for disbudding?
cornual nerve
Endoscopic entry route to guttral pouch
go up through ventral meatus –> poke it through pharyngeal slit and you’re in the pouch
adductor of the vocal folds?
cricoaryentoid muscle
what nerve is the main sensory supply to all the maxilla?
infraorbital nerve
Drainage pathway for the all the sinuses?
rostal and caudal maxillary sinus share the opening –> space between dorsal and ventral conchi into the middle meatus of the nasal cavity
How does the frontoconchal drain?
from the frontal sinus to the caudal maxillary sinus -> space between dorsal and ventral conchi into the middle meatus of the nasal cavity
sinus infection in horses?
roots of the cheek teeth (maxillary teeth) stimulates the superior alveolar nerve
what sinus can be affected in cattle if you dehorn too late?
frontal sinus as it can grow out into the developing horn
What structure would be affected if you were too high up (more dorsal) to the line from the nasoincisive notch and the medial canthus of the eye
the nasolacrimal duct
what happens if you hit the nasolacrimal duct?
the tears in the eye wouldnt have a drinage pathway so they would be running down the face
whats the role of the stylohyoid bone?
to seperate the medial and lateral compartments of the guttral pouch
what is the anchor part of the tongue?
lingual process of basihyoid
what cartilage allows adduction and abduction of the vocal cords
arytenoid cartilages rotate on the top of the thyroid cartilage
what muscle abducts the vocal cord?
dorsal cricoarytenoid muscle
Explain what happens during laryngeal hemiplegia (roaring)
the reccruent larygngeal nerve has become damaged – happens on the left usually – maybe be attacked by lymph nodes when the horse is suick which invades the vagas and denervates L recurrent laryngeal branch
Where does the left recurrent laryngeal nerve go?
the left recurrent laryngeal nerve reflects off the vagus around the arch of the aorta
what happens if you deinnervates the dorsal cricoarytenoid muscle
if the muscle is damaged you get an instability to the vocal cords on the side thats affected (becomes floppy/passive)
what causes the roaring sound?
when the horse breathes in the vocal fold flaps in the wind which creates the vibration that makes the noise
