The auditory and vestibular apparatus

Question 1

what vessels run near the ear

Answer 1

signmodi sinus and carotid artery

Question 2

great auricular nerve supplies the pinna of the ear - what plexus and nerve roots is it derived from

Answer 2

cervical plexus

C2,3

Question 3

auricular temporal nerve - branch of

Answer 3

mandibular trigeminal - anterior pinna

other nerves other vagus and facial nerve

Question 4

blood supply of the ear

branches of external carotid

Answer 4

superficial temporal artery

and posterior auricular artery

Question 5

how does the ear connect to the nasopharynx

Answer 5

sustain tube or pahryngotympanic tube

equalises air pressure within tympanic cavity

mor horizontaal in children -draws in mcuus

Question 6

where are the 2 bend of the facial nerve

Answer 6

The pyramidal eminence is the second bend in the facial nerve, where the nerve runs downward as the mastoid segment.
In the temporal part of the facial canal, the nerve gives rise to the nerve to the stapedius muscle and chorda tympani

Question 7

middle ear is connected to

Answer 7

ant eustrastichu tube to peahen
post to mastoid Antrum and air cells
meninges and middle cranial foes through unossfied petryosquamosal suture

middle ear veins to sinus nada meninges

Question 8

middle to inner ear what window

Answer 8

oval and round window
stapes connects oval window

consigns of bony labyrinth ( membranous labrythn in this

Question 9

perilymph is similar to CSF

merbnaous lbrynth contains what

Answer 9

endolymph with high potassium content

Question 10

utricle and sauce detect linear movement whereas the cochlea detect what

Answer 10

angula rmvoemnet

Question 11

intneral ear develops from what

Answer 11

otic places of the ectoderm

10th week scala vestiboli and tympani formed

epithelial lining oc cholera ducts are hair cell s

Question 12

middle ear formed by

Answer 12

endoderm - ( tubotypmanic recess) - then into mastoid air cells

Question 13

ear ossicles formed from

Answer 13

cartilage of frist pahyngeal arch

stapes - 2nd pahyrngeal arches

Question 14

tensor tympani supplied by

Answer 14

mandibular nerve of first pharyngeal nerve

facial nerve supplie sstapeidus - 2nd pahyngela arch

Question 15

external auditory meatus formed by what

Answer 15

first pharyngeal cleft

Question 16

auricle develops from

Answer 16

auricular hillocks fro 1st and 2nd pahyrngela arches

Question 17

what vessel is below the middle ear

Answer 17

internal jugular vein

Question 18

contents of the middle ear

Answer 18

Auditory ossicles (malleus, incus, and stapes).
Stapedius muscle – supplied by Branch of CN VII.
Tensor tympani muscle - supplied by Branch of CN V3.
Chorda tympani branch of facial nerve.
Tympanic plexus of glossopharyngeal nerves.

Question 19

A 6 year old boy recently failed a school hearing screening test and is waiting for a repeat hearing test in hospital.
He developed a cold 10 days ago and soon after that developed right earache. He had a fever and was crying with pain on and off. The out of hours service said he had an ear infection but that they would not give antibiotics because “we don’t give those for ear infections anymore…” 5 days later he was still unwell with a temperature, earache and now a headache. Mum was so worried that she attended the ED.

What do you think the diagnoses are here?

Answer 19

Glue ear, Ascending viral and bacterial infection along the ET, Acute otitis media, sigmoid sinus thrombosis, ? Cerebral abscess

Question 20

A 30 year old lady presents with gradual onset of right hearing loss. It has come on over the last year, particularly when she was pregnant with her first child (who is now 3 months old). She is concerned that when she lies on her left at night she can’t hear the baby waking until the baby is screaming and upset.
She has no relevant medical past history. She has always been in good health and has had no prior problems with her ears. Her mother and grandmother also had difficulty hearing in one ear. Her mother had a successful operation to improve it but her grandmother wore hearing aids and was very deaf when in her 80s before her death.
Examination of the ears is normal except for a hearing loss detected on the right.

Answer 20

his lady has a condition called otosclerosis that fuses the stapes bone at the oval window, preventing movement at that synovial joint. Otosclerosis is an autosomal dominant genetic disorder but with variable penetrance and also environmental causative factors. Affects F>M

glue ear also causes conductive hearing loss

Question 21

The hair cells in the utricle and saccule maculae are innervated by fibres

Answer 21

of the vestibular branch of the vestibulocochlear nerve.

Question 22

Considering the embryological development of the pinna, how many auricular hillocks combine to form the external ear?

Answer 22

6

Question 23

Which pharyngeal arches are the mesenchymal hillocks derived from?

Answer 23

Hillocks 1 to 3 from the 1st pharyngeal arch

Hillocks 4 to 6 from the 2nd pharyngeal arch

Question 24

Pinna development starts in the 6th week and is completely finished (with formed ear canal and ear at level of eyes) in 32nd week – it can go wrong…..leading to:

Answer 24

Abnormal shaped ears
Incompletely developed ears, including absent pinna and ear canal
Cysts and sinuses from failed fusion