Anatomy - Ear

Question 1

which bone is most important with regards to the ear

Answer 1

temporal bone

Question 2

two parts of the temporal bone

Answer 2

squamous and petrous

Question 3

name and articulations of thinnest part of the skull

Answer 3

pterion

- frontal, parietal, temporal and sphenoid bones

Question 4

which nerves run within the temporal bone

Answer 4

CN VII/VIII

Question 5

what prevents dislocation of TMJ

Answer 5

zygomatic process

Question 6

which artery runs behind the pterion

Answer 6

middle meningeal

Question 7

what is a feature of both the temporal and occipital bones

Answer 7

jugular foramen

Question 8

what passes through the jugular foramen

Answer 8

CN IX, X, XI and internal jugular vein

Question 9

bones of the anterior cranial fossa

Answer 9

frontal
ethmoid
sphenoid

Question 10

bones of the middle cranial fossa

Answer 10

sphenoid

temporal (mainly this)

Question 11

bones of the posterior cranial fossa

Answer 11

temporal

occipital (mainly this)

Question 12

cranial nerves leaving in anterior fossa

Answer 12

CN 1

Question 13

cranial nerves leaving in middle fossa

Answer 13

CN II, III, IV, Va, Vb, Vc, VI

Question 14

cranial nerves leaving in posterior fossa

Answer 14

CN VII, VIII, IX, X, XI, XII

Question 15

another name for auricle

Answer 15

pinna

Question 16

contents of external ear

Answer 16

auricle to tympanic membrane via EAM

Question 17

contents of middle ear

Answer 17

tympanic membrane to oval window and eustachian tube

Question 18

contents of internal ear

Answer 18

oval window to internal acoustic meatus

Question 19

function of external ear

Answer 19

collects and conveys sound waves to tympanic membrane

Question 20

function of middle ear

Answer 20

amplifies and conducts sound waves to internal ear

Question 21

function of internal ear

Answer 21

converts special sensory information to fluid waves then APs which are then conducted to the brain

Question 22

type of cartilage at ear

Answer 22

elastic

Question 23

contents of ear canal

Answer 23

EAM, 1/3 cartilage, 2/3 bony, lined with skin,

Question 24

what produces earwax

Answer 24

ceruminous glands

Question 25

name for folded over bit of external ear

Answer 25

helix

Question 26

sensory supply to most of external ear, including lobe

Answer 26

anterior rami of C2/3 spinal nerves

Question 27

sensory supply to inferior parts of EAM and tympanic membrane

Answer 27

vagus

Question 28

sensory supply to superior parts of EAM and most of tympanic membrane

Answer 28

CN V3 (mandibular)

Question 29

lymphatic drainage of lateral surface of superior half of ear

Answer 29

parotid nodes

Question 30

lymphatic drainage of cranial surface of superior half of ear

Answer 30

mastoid nodes and deep cervical

Question 31

lymphatic drainage of rest of auricle including lobe

Answer 31

superficial cervical lymph nodes

Question 32

where does all lymph of ear eventually drain to

Answer 32

deep cervical lymph nodes in carotid sheath thoracic duct/right lymphatic duct venous angle

Question 33

thin part of tympanic membrane seen superiorly on otoscope

Answer 33

pars flaccida

Question 34

most inwardly depressed part of tympanic membrane

Answer 34

umbo

Question 35

thick part of tympanic membrane seen posteroinferiorly

Answer 35

pars tensa

Question 36

way to pull ear in child

Answer 36

posteroinferiorly

Question 37

way to pull ear in adult

Answer 37

posteriosuperiorly

Question 38

nerve supply to external surface of tympanic membrane

Answer 38

CN V3 (auriculotemporal branch)

Question 39

nerve supply to internal surface of tympanic membrane

Answer 39

CN IX

Question 40

sensory innervation of CN IX

Answer 40

``` middle ear cavity eustachian tube nasopharynx oropharynx tonsils ```

Question 41

what does the eustachian tube connect

Answer 41

tympanic cavity to lateral wall of nasopharynx

Question 42

sensory supply to laryngopharynx

Answer 42

CN X

Question 43

close relation of opening of eustachain tube

Answer 43

adenoid tonsil

Question 44

what pulls on the umbo to make the indentation of the tympanic membrane

Answer 44

handle of the malleus

Question 45

what fits into the oval window

Answer 45

footplate of the stapes

Question 46

what is the tympanic cavity proper

Answer 46

posterior to the tympanic membrane

Question 47

what is the aditus

Answer 47

doorway into the antrum from the epitympanic recess

Question 48

features of the facial nerve

Answer 48

special sensory, sensory, motor and parasympathetic

Question 49

what is the chorda tympani

Answer 49

branch of the facial nerve which courses over the internal tympanic membrane and supplies the taste buds of the anteriror 2/3 of the tongue also gives parasympathetic supply to the submandibular and sublingual salivary glands

Question 50

base of skull foramen which facial nerve courses through

Answer 50

IAM and stylomastoid foramen

Question 51

function of tensor tympani

Answer 51

dampens noise from chewing

Question 52

function of stapedius

Answer 52

protects internal ear against excessive noise

Question 53

nerve that chorda tympani courses with to supply taste

Answer 53

lingual nerve (branch of V3)

Question 54

how to clinically test muscles of facial expression

Answer 54

frown, close eyes tightly, smile and puff out cheeks

Question 55

what is the bony labyrinth

Answer 55

perilymph filled spaces inside otic capsule

Question 56

features of perilymph

Answer 56

similar to extracellular fluid

Question 57

features of endolymph

Answer 57

similar to intracellular fluid

Question 58

fluid in semi-circular canal

Answer 58

endolymph

Question 59

steps of sound transmission in the internal ear

Answer 59

- sound waves make tympanic membrane vibrate - vibrations transmitted through ossicles - base of stapes vibrates in oval window - vibration of stapes creates pressure waves in perilymph - hair cells in cochlea move, neurotransmitter released, AP stimulated and conveyed to brain via cochlear nerve - pressure waves descend and become vibrations again - pressure waves are dampened at round window

Question 60

where do CN VII and VIII connect to the brainstem

Answer 60

junction between pons and medulla oblongata