Lecture 9: Surgical Anatomy of Head and Neck (Wronski)

Question 1

anesthetic injection of supraorbital n. will desensitize:

Answer 1

upper eyelid for optho exam (sensory)

Question 2

anesthetic injection of infraorbital n. will desensitize:

Answer 2

rostral upper surface of face, including the upper lip to suture lacerations (sensory)

Question 3

anesthetic inj. of mental n. will desensitize:

Answer 3

lower lip/chin to suture lacerations (sensory)

Question 4

anesthetic inj. of maxillary n. will desensitize:

Answer 4

upper dentition for dental procedures (sensory)

Question 5

anesthetic inj. of mandibuloalveolar n. will desensitize:

Answer 5

lower jaw/dentition for dental procedures (sensory)

Question 6

anesthetic inj. of palpebral br. will desensitize:

Answer 6

orbicularis oculi m. for optho exam (motor)

Question 7

mental n. is a cranial br. of what nerve?

Answer 7

mandibulo-alveolar

Question 8

Where is maxillary n. blocked?

Answer 8

deep injection into the pterygopalatine fossa (near lateral canthus of the eye)

Question 9

where is mandibuloalveolar n. blocked?

Answer 9

intersection of horizontal line extended caudally along occlusal surface of teeth and vertical line dropped ventrally from lateral canthus of eye

Question 10

which two nerves should you block to remove both motor and sensory input to the eyelids for an optho exam? Where do you inject? **

Answer 10

frontal (supraorbital) and palpebral n. A single injection at the supraorbital foramen accomplishes this, because the palpebral n. travels next to the supraorbital foramen

Question 11

tarsorrhaphy

Answer 11

Suturing the eyelids together. Performed after enucleation of the eyeball or for treatment of corneal ulcers

Question 12

What nerves must be blocked for a tarsorrhaphy procedure?

Answer 12

supraorbital, palpebral, and zygomaticofacial. The zygomaticofacial is sensory to the lower eyelid and therefore must also be blocked

Question 13

Site of nerve block for tarsorrhaphy

Answer 13

at the junction of the ventral rim of the orbit and the supraorbital portion of the zygomatic arch (NOT the supraorbital foramen)

Question 14

What artery supplies horns in horned animals?

Answer 14

cornual a. (a branch of the superficial temporal). Must be ligated in dehorning

Question 15

Dehorning involves blocking of which nerve? Site of injection?

Answer 15

cornual n. Inject ventral to temporal line b/w the lateral angle of eye and the horn. Also Inject SQ along dorsomedial border of horn in case branches of the infratrochlear n. extend into the horn

Question 16

potential complication of cosmetic dehorning? How can this be avoided?

Answer 16

infection of frontal sinus. Results due to communication b/w exterior and the caudal frontal sinus via the cornual diverticulum. Dehorn before 6 mos. of age, because the diverticulum doesn’t invade the horn until this time

Question 17

How to treat infected frontal sinus?

Answer 17

Perform trephination (bore circular hole into caudal or rostral sinus to drain it and introduce antibiotic solution)
*avoid the frontal vein, which drains into the supraorbital foramen in the cow*

Question 18

tx of infection of maxillary sinus

Answer 18

trephination caudodorsal to facial tuberosity to enter maxillary sinus

Question 19

Do the rostral and caudal maxillary sinuses communicate?

Answer 19

NO

Question 20

How does the frontal sinus communicate with the caudal maxillary sinus?

Answer 20

nasomaxillary aperture

Question 21

what space lies between the dorsal and ventral concha?

Answer 21

middle nasal meatus

Question 22

Where do the rostral and caudal maxillary sinuses drain?

Answer 22

through the nasomaxillary aperture into the middle nasal meatus

Question 23

tears drain through the:

Answer 23

nasolacrimal duct

Question 24

Things to avoid during trephination of rostral or caudal maxillary sinuses

Answer 24

dorsal buccal n.
transverse facial/deep facial veins
nasolacrimal duct

Question 25

roots of 3rd and 4th cheek teeth project into which sinus in the horse?

Answer 25

rostral maxillary sinus

Question 26

roots of 5th and 6th cheek teeth project into which sinus in the horse?

Answer 26

caudal maxillary sinus

Question 27

Access to roots of teeth for repelling teeth can be gained in which sinuses?

Answer 27

maxillary and frontal sinuses. Teeth are driven from the sinus into the oral cavity for extraction

Question 28

How to repell the 6th cheek tooth?

Answer 28

It is difficult to expose the root through the caudal maxillary sinus, so perform trephination of sinus flap of frontal sinus through the frontal maxillary opening

Question 29

what is the guttural pouch?

Answer 29

bilateral mucous sacs that are ventral diverticulae of the auditory tubes situated at the base of the cranium and atlanto-occipital joint

Question 30

how can respiratory infection travel to guttural pouch?

Answer 30

mucous memb. of guttural pouch is continuous with that of the nasopharynx at the auditory tube

Question 31

Signs of infected guttural pouch *

Answer 31

• epistaxis (nose bleed)
• swelling at caudal angle of mandible
• empyema (collection of pus)
• chondroid bodies (solidified pus)
• dysfunction of cranial nerves 3,7,9,10,11,12)

Question 32

how to drain infection of guttural pouch

Answer 32

insert catheter through ventral nasal meatus –> auditory tube –> guttural pouch

Question 33

epistaxis from infected guttural pouch is usually from which vessels?

Answer 33

internal carotid and maxillary vein?

Question 34

common sign of cranial n. dysfunction secondary to infection of guttural pouch

Answer 34

dysphagia due to trauma to pharyngeal branches of vagus n.

Question 35

which lymph nodes lie immediately ventral to guttural pouch?

Answer 35

medial retropharyngeal lymph nodes

Question 36

laryngeal hemiplegia (roaring) *

Answer 36

Trauma to recurrent laryngeal n. results in paralysis of cricoarytenoideus dorsalis m., which abducts the vocal folds. Leads to partial occlusion of laryngeal cavity as the vocal folds project too far medially into the air current during inspiration

Question 37

what side does roaring most often occur on?

Answer 37

left side (90% of the time!)

Question 38

Where do the cranial laryngeal n. and a. enter the larynx?

Answer 38

between the cricoarytenoideus lateralis and dorsalis mm.

Question 39

ventriculoectomy

Answer 39

surgical correction of laryngeal hemiplegia (roaring). Involves eversion and excision of the laryngeal saccule which results in formation of granulation tissue between the vestibular and vocal folds that hopefully pushes the vocal fold laterally.

Question 40

What is a tie back?

Answer 40

sx correction of laryngeal hemiplegia in which suture is placed through the muscular process of the arytenoid cartilage and anchored at the caudal portion of the median ridge of the cricoid cart., which simulates the fx of the atrophied cricoarytenoideus dorsalis m.

Question 41

the opening of the laryngeal saccule is known as

Answer 41

lateral ventricle