Anatomy of the Ear

Question 1

what is the pterion?

Answer 1

the thinnest part of the skull

Question 2

the sqaumous part is superior/inferior to the petrous part

Answer 2

sqaumous is superior

petrous is inferior

Question 3

identify these structures

Answer 3

Question 4

which bones form the base of the skull?

n.b- as if looking down

Answer 4

frontal

ethmoid

sphenoid

temporal

occipital

Question 5

what are the boundaries of eh external ear?

Answer 5

auricle to tympanic membrane

Question 6

what is the function of the external ear?

Answer 6

collects and conveys sounds waves to tympanic membrane

Question 7

what are the boundaries of the middle ear?

Answer 7

tympanic mebrane to oval window

Question 8

what is the function of the middle ear?

Answer 8

amplifies and conducts sound waves to the internal ear

Question 9

the eustachian tube belongs to which part of the ear?

Answer 9

middle ear

Question 10

what are the boundaries of the internal ear?

Answer 10

oval window to internal acoustic meatus

Question 11

what is the function of the internal ear?

Answer 11

converts special sensory information into fluid waves then APs and conducts these to the brain

Question 12

what is the auricle?

Answer 12

visible part of the ear

Question 13

where are three features of the auricle?

Answer 13

helix

tragus

ear lobe

Question 14

what are some lympthnodes in the head and neck that the auricle drains to?

Answer 14

parotid lymph nodes

mastoid lymph nodes

superficial cervical lymph nodes

Question 15

auricle lymphatic drainage all eventually drians to where?

Answer 15

deep cervical lymph nodes (in carotid sheath)

thoracic duct or right lymphatic duct

Question 16

the external ear is made up of elastic cartilage true/false?

Answer 16

true- avascular

Question 17

earwax is produced by what ?

Answer 17

ceruminous glands

Question 18

an otoscope allows you to examine what?

Answer 18

the EAM and tympanic membrane

Question 19

the EAM is curved/straight in children?

Answer 19

sraight in children

curved in adults

Question 20

when perfroming an otoscope exam how should you pull the ear in children and aduls?

Answer 20

posteroinferiorly in children

posterosuperiorly in adults

Question 21

what is the pars flaccida?

Answer 21

thinnest part of tympanic membrane- found superiorly

Question 22

what is the umbo?

Answer 22

most inwardly depressed part of tympanic membrane

Question 23

what is the thickest part of the tympanic membrane?

Answer 23

pars tensa

Question 24

the external surface of the typanic membrane is innervated by what?

Answer 24

CN V3

internal surface- CN IX

Question 25

glossopharyngeal nerve provides sensory innervation to what?

Answer 25

middle ear cavity eustachian tube nasopharynx osopharynx tonsils

Question 26

what are the auditory ossicles?

Answer 26

3 bones of the middle ear

Question 27

the auditory ossicles articulate via what joints?

Answer 27

synovial joints

Question 28

handle of ______ adherent to internal aspect of tympanic mebrane creates the umbo

Answer 28

malleous

Question 29

the ______ recess is superior to the tympanic membrane

Answer 29

epitympanic recess

Question 30

what in the ear is also known as the 'stirrup'

Answer 30

stapes

Question 31

the base (footplate of the stapes) fits into what?

Answer 31

the oval window

Question 32

what si the function of the stapedius muscle?

Answer 32

reduces stapes movement to protect the internal ear from excessive noise

Question 33

describe the path of the facial nerve through petrous temporal bone

Answer 33

internal acoustic meatus facial canal of petrous temporal bone stylomastoid foramen

Question 34

the facial nerve gives off a branch just before reaching the stylomastoid foramen. What is this branch called?

Answer 34

chorda tympani

Question 35

loss of this structure in the cheeks is a clinical sign of malnutrition

Answer 35

loss of buccal fat pad

Question 36

lacerations across this part of the lip must be carefully sutured by a specialist

Answer 36

vermillion border of the iips

Question 37

what can you ask a patient to do to clinically test muscles of facial expression?

Answer 37

frown close eyes tightly smile puff out cheeks

Question 38

what conditon affects CN VII resulting in the inability to use your facial muscles?

Answer 38

Bells palsy

Question 39

what are the two parts of the vestibulocochlear nerve?

Answer 39

cochlear nerve- hearing vestibular nerve- balance

Question 40

the internal ear is contained within what?

Answer 40

Otic capsule

Question 41

define bony labrynth

Answer 41

sapce within the otic capsule filled with perilymph

Question 42

perilymph is similar ot extra/intracellular fluid?

Answer 42

perilymph similar to **extra**cellular fluid endolymph similar to **intra**cellular fluid

Question 43

endolymph is found where?

Answer 43

membranous labyrinth suspended inside perilymph of bony labyrinth

Question 44

what is the cupula of the cochlea?

Answer 44

apex of spiral

Question 45

APs from the cochlear duct are conducted to the brainstem in what nerve?

Answer 45

cochlear nerve

Question 46

APs in the semicircular ducts are conducted to the brainstem in what nerve?

Answer 46

vestibular nerve

Question 47

what is the cochlear duct?

Answer 47

long baloon like structure within cochlea filled with perilympth

Question 48

what are the semicircular ducts?

Answer 48

inter-linked balloon like structures within semicircular canals filled with endolympth

Question 49

describe sound transmission (7)

Answer 49

1. sound waves make tympanic membrane vibrate 2. vibrations transmitted through ossicles 3. base of stapes vibrates in oval window 4. vibration of stapes creates pressure waves in perilympth 5. hair cells in cochlea are moved nueotransmitter released cochlear nerve picks up APs 6. pressure waves descend and become vibrations again 7. pressure waves are dampened at roudn window

Question 50

damage to the facial nerve could present with what?

Answer 50

struggles with facial expression dry mouth/eyes loss of taste from ant 2/3rds of tongue n.b usually ipsilateral i.e right side loss= right side symtpoms