anatomy Qs

Question 1

loss of gag reflex, unilateral wasting of sternocleidomastoid, which part of the skull base has the tumour invaded?

Answer 1

jugular foramen
glossopharyngeal nerve, vagus and spinal accessory all pass through here

(spinal accessory = motor control to sternocleidomastoid)
(gag reflex = vagus (motor) + glossopharyngeal (sensory))

Question 2

which nerve passes through foramen ovale

Answer 2

CN V3 (mandibular div.)

Question 3

which nerve supplies the internal aspect of the anteroinferior tympanic membrane?

Answer 3

INTERNAL surface of tympanic membrane is supplied by glossopharyngeal (CN IX)

think of referred pain from oropharynx

Question 4

45 y/o women admitted with headaches, dizziness + vomiting. radiographic reveals tumour. she has also dryness of nasal + paranasal sinuses, loss of lacrimation and loss from anterior 2/3 of tongue. what is the most likely site of tumour?

Answer 4

internal acoustic meatus
- carries both CN VII + VIII (vestibulocochlear - explains dizziness)

vidian/greater petrosal supplies nasal + paranasal lacrimation

Question 5

34y/o with headaches + hyperacusis on right side. reduced sensation on right side of jaw + tongue. right sided masseteric atrophy. injury to which cranial nerve is responsible?

Answer 5

trigeminal

hyperacusis due to innervation of tensor tympani (not tightening up ossicluar chain)

Question 6

35 y/o women with 4 weeks of hoarse voice. voice is weak, unable to have long convos. recently overcame URTI. noted some difficulty on swallowing liquids with minor choking, solid are fine.

Answer 6

unilateral aDuctor vocal cord paralysis

-> unable to shut fully - choking

Question 7

25 y/o professional singer, distressed cant reach high notes, cant maintain high “eeee” sound, however deeper sounds seem to be held much better

which laryngeal muscle most likely affected?

Answer 7

cricothyroid

Question 8

which laryngeal muscles that cause aDduction of vocal folds?

Answer 8

lateral cricoarytenoid - rotates folds together

arytenoid - slides posterior to create tight seal

Question 9

which laryngeal muscle abducts vocal folds?

Answer 9

posterior cricoaryteoid

Question 10

innervation of cricothyroid muscle

Answer 10

external pharyngeal nerve

-> NOT by recurrent laryngal

Question 11

which muscle is responsible for increasing the pitch of sound?

Answer 11

cricothyroid

tenses vocal ligament

Question 12

which muscle is responsible for lowering the pitch of sound?

Answer 12

thyroarytenoid

abive cricothyroid

Question 13

tumour in infratemporal fossa, examination reveals loss of general sensation to anterior 2/3 of tongue but taste + salivation are intact?
what nerve is most likely affected?

Answer 13

proximal lingual

chorda tympani = saliv in floor, tast to ant 2/3
lingual = general sensation ant 2/3

Question 14

which nerve does lingual nerve come from?

Answer 14

V3 mandibular div

Question 15

submandibular gland removed, in recovery mouth looks odd (isnt moving) when she smiles on the side of surgery?

Answer 15

marginal mandibular branch of FACIAL NERVE

–> GOES ALONG BY SUBMANDIBULAR GLAND + UP TO MUSCLES around mouth

Question 16

neck swellling anterior just above jugular notch, slightly to right hand side

what is most likely origin of mass?

Answer 16

thyroid gland

Question 17

role of trigeminal somatosensory system (CN V)

Answer 17

protective ffect - if something harmful sniffed it will halt inhalation to protect lungs

Question 18

which cranial nerves sense taste and where from?

Answer 18

CN VII (chorda tympani) - ant 2/3 tongue

CN IX (glossopharyn) = pos 1/3 tongue

CN X (vagus) = areas that arent tongue - epiglottis, pharynx

Question 19

life span of taste buds

Answer 19

10 ish days

replaced from basal cells within the taste bud

Question 20

what do the otolith organs detect?

Answer 20

forward + backward movements
gravitational forces

(urtricle + saccule)

Question 21

what kind of movements does urticle detect? saccule?

Answer 21

horizontal = urticle

vertical = saccule