Anatomy of the Ear

Question 1

What comprises the external ear?

Answer 1

auricle to the tempanic membrane (via the external acoustic meatus)

Question 2

What is the role of the external ear?

Answer 2

collects and conveys sound waves to the tempanic membrane

Question 3

What comprises the middle ear?

Answer 3

tempanic membrane to the oval window and Eustachian tube

Question 4

What is the role of the middle ear?

Answer 4

amplifys and conducts sound waves to the inner ear

Question 5

What comprises the inner ear?

Answer 5

oval window to the internal aucoustic meatus

Question 6

What is the role of the inner ear?

Answer 6

converts special sensory information into fluid waves then action potentials then conducts the action potentials to the brain

Question 7

What are the two parts to the temporal bone?

Answer 7

upper squamous part

lower petrous part

Question 8

What nerves are contained within the temporal bone?

Answer 8

facial CN VII

vestibulocochlear CN VIII

Question 9

What is the Pterion?

Answer 9

H shaped suture between the frontal, parietal, temporal and spehnoid bone

Question 10

Is the Pterion thin or thick?

Answer 10

thin

Question 11

What is the external acoustic meatus?

Answer 11

hole of the ear

Question 12

Where is the internal acoustic meatus found?

Answer 12

runs beside the jugular vein, CNVII, CNVIII and the labrynthine artery and vein - in the circle of willis

Question 13

What supplies the taste to the anterior 2/3rds of the tongue?

Answer 13

facial nerve - chorda tympani

Question 14

What supplies secretomotor to the salivary and lacrimal glands?

Answer 14

facial nerve

Question 15

What supplies motor to the stapedius?

Answer 15

facial nerve

Question 16

What type of cartilage makes up the external ear?

Answer 16

elastic cartilage

Question 17

What makes up the ear canal?

Answer 17

outer 1/3rd cartilage and medial 2/3rds bony

lined by skin

Question 18

What secreted ear wax in the ear canal?

Answer 18

ceruminous glands

Question 19

What are all of the nerves that supply the pinna of the ear? (outer fleshy bit)

Answer 19

C2,3 spinal nerves
CN V3
CN X
CN VII

Question 20

The vagus nerve supplies the some of the ear canal, what else does it supply that may be affected when you stick your finger in your ear?

Answer 20

back of the throat

Question 21

What is the lymphatic drainage of the superior half (lateral surface) of the auricle?

Answer 21

parotid lymph nodes

Question 22

What is the lymphatic drainage of the inferior half (cranial surface) of the auricle?

Answer 22

mastoid lymph nodes

Question 23

What is the lymphatic drainage of the rest of the auricle?

Answer 23

superficial cervical lymph nodes

Question 24

How must the external auricular meatus be examined?

Answer 24

pull up the pinna to straighten the EAM

Question 25

How are childrens EAMs different?

Answer 25

they are already straight so dont need to pull on them - may damage the tympanic membrane if you do

Question 26

What is the thick part of the tympanic membrane called?

Answer 26

pas tensa

Question 27

What is the thin part of the tympanic membrane called?

Answer 27

pas flaccida

Question 28

What is the nerve supply ot the external surface of the tympanic membrane?

Answer 28

CN V3

Question 29

What is the nerve supply ot the internal surface of the tympanic membrane?

Answer 29

CN IX - glossopharyngeal

Question 30

What are the 3 ossicles of the middle ear?

Answer 30

malleus (hammer) incus (anvil) stapes (stirrip)

Question 31

What sensory supply does the glossopharyngeal nerve supply?

Answer 31

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

Question 32

What are the two muscles of the inner ear?

Answer 32

stapedius | tensor tympani

Question 33

What recess is superior to the tympanic membrane?

Answer 33

epitympanic recess

Question 34

How do the auditory ossicles articulate?

Answer 34

synovial joints

Question 35

What creates the umbo?

Answer 35

handle of the malleus

Question 36

What connects the internal acoustic meatus to the stylomastoid foramen?

Answer 36

facial nerve

Question 37

Where is the opening to the Eustachian tube?

Answer 37

below the pharangeal tonsil - adenoid

Question 38

What is the path of the Eustachian tube?

Answer 38

connects the anterior wall of the middle ear cavity to the nasopharynx

Question 39

Why can tonsils mimic ear pain?

Answer 39

both have the same sensory nerve supply - CN IX glossopharyngeal

Question 40

What is the main nerve supply to the laryngopharynx?

Answer 40

CN X

Question 41

What is the role of the eustachian tubes?

Answer 41

equalises pressure in the ears by contraction of muscles

Question 42

What is the pathway of the facial nerve?

Answer 42

comes off the CNS at the ponto medullary junction goes into the IAM in the posterior cranial fossa goes out the temporal bone through the stylomastoid foramen or the IAM

Question 43

What is the Chorda tympani?

Answer 43

branch of the CNVII

Question 44

What is the role of the chorda tympani?

Answer 44

supplies the taste to anterior 2/3rds of the tongue | parasympathetic supply to the submandibular and sublingual glands

Question 45

What supplies the stapedius?

Answer 45

facial nerve

Question 46

Whtat is the role of the stapedius?

Answer 46

smallest muscle in the body | reduces the stepes movement to protect the internal ear from excessive noise

Question 47

What muscle is lost in diseases such as anorexia?

Answer 47

buccal fat pad

Question 48

Where is the Vermillion border?

Answer 48

between the lip and adjacent normal skin

Question 49

Where is the inner ear found?

Answer 49

petrous part of the temporal bone

Question 50

What are the two parts of the vestibulocochlear nerve and what do they do?

Answer 50

cochlear nerve - hearing | vestibular nerve - balance

Question 51

Where is the otic capsule found?

Answer 51

inner ear

Question 52

What is contained in the otic capsule?

Answer 52

perilymph in the the bony labrynith and suspended in the perilymph there is endolymph

Question 53

What are the different parts of the otic capsule?

Answer 53

semicircle canals cochlea round window oval window

Question 54

What is the apex of the cochlea called?

Answer 54

cupula

Question 55

What do both the cochlea and semicircular canals contain?

Answer 55

ducts filled with lymph

Question 56

What is contained within the otic capsule that are clusters of hair cells that detect the movement of endolymph?

Answer 56

vestibular apparatus | clusters of hair cells are called maculae

Question 57

What type of movement do the semicircular ducts detect?

Answer 57

angular

Question 58

What type of movement do the utricles detect?

Answer 58

horizontal

Question 59

What type of movement do the saccules detect?

Answer 59

verticle

Question 60

How is sound transmitted?

Answer 60

sound waves make tympanic membrane vibrate vibrates are transmitted through the ossicles base of the stepes vibrates in the oval window and causes pressure waves in the perilymph hair cells in the cochlea are moves and APs are stimulated and convayed in the brain by the cochlear nerve pressure waves descend and become vibrations again pressure waves are dampened at the round window

Question 61

Describe the cochlear apparatus?

Answer 61

receptor cells in the organ of Lorti detect auditory stimuli | receptor cells are located in the basilar membrane of the cochlear duct

Question 62

What two parts does the spiral ligament divide the cochlear duct into?

Answer 62

scala vestibuli | scala tympani

Question 63

How does the vestibular nerve connect with the brainstem?

Answer 63

pontomedullary junction goes through IAM then splits into cochlear and vestibular nerve axons

Question 64

What does the cochlear nerve form?

Answer 64

spiral nerve

Question 65

What does the vestibular nerve form?

Answer 65

semicircular ducts, utricle and saccule