Clinical Anatomy of the Ear

Question 1

What are the 3 anatomical divisions of the ear?

Answer 1

External
Middle
Inner

Question 2

What are the 2 functional divisions of the ear?

Answer 2

Hearing (auditory)

Balance (Vestibular)

Question 3

Where are all divisions of the ear found?

Answer 3

In the temporal bone

Question 4

What nerves are found in the temporal bone?

Answer 4

Facial (CNVII)

Vestibulocochlear (CN VIII)

Question 5

What are 6 features of the temporal bone?

Answer 5

Squamous part
Petrous part
Zygomatic process
External acoustic meatus
Mastoid process
Styloid process

Question 6

What is the thinnest part of the skull?

Answer 6

Pterion

Question 7

What makes up the pterion?

Answer 7

Frontal bone
Parietal bone
Temporal bone
Sphenoid bone

Question 8

What cranial nerve enter/exit the the skull in the frontal bone?

Answer 8

CN 1

Question 9

What cranial nerve enter/exit the the skull in the middle region of the base of the skull/

Answer 9

CN 2,3,4,5,6

Question 10

What cranial nerve enter/exit the the skull in the occipital region of the skull?

Answer 10

CN 7,8,9,10,11,12

Question 11

What 3 things pass through the internal acoustic meatus?

Answer 11

CN VII
CN VII
Labyrinthe artery and vein

Question 12

What does the facial nerve supply?

Answer 12

Motor to face
Motor to stapedius
Taste to anterior 2/3rds of tongue
Secretomotor to salivary and lacrimal glands
General sensation to external ear

Question 13

What does the vestibulocochlear nerve supply?

Answer 13

Balance

Hearing

Question 14

Where does the labyrinthine artery come from?

Answer 14

Circle of willis

Branch of anterior inferior cerebellar artery

Question 15

Where is the external ear?

Answer 15

Auricle to tympanic membrane

Question 16

What is the function of the external ear?

Answer 16

Collects and conveys sound waves to tympanic membrane

Question 17

Where is the middle ear?

Answer 17

Tympanic membrane to oval window + eustachian tube

Question 18

What is the function of the middle ear?

Answer 18

Amplifies and conducts sound waves to the internal ear

Question 19

Where is the internal ear?

Answer 19

Oval window to internal acoustic meatus

Question 20

What is the function of the internal ear?

Answer 20

Converts special sensory information

Question 21

What does the internal ear convert special sensory information into?

Answer 21

Fluid waves
The Action Potentions
Conducts AP to brain

Question 22

What is the skeletal part of the external ear?

Answer 22

Temporal bone
Elastic cartilage
Avascular
Nutrients from skin

Question 23

Where does the ear canal begin?

Answer 23

At the external acoustic meatus

Question 24

What is the ear canal composed of?

Answer 24

1/3rd cartilage

2/3rds bone

Question 25

What is the ear canal lined with?

Answer 25

Skin

Question 26

What does the ear canal produce and how?

Answer 26

Earwax via ceruminous glands

Question 27

What nerves are involved in supplying the auricle?

Answer 27

C2,3 spinal nerves (Helix, Antihelix) CNV3 - superior parts of EAM and most of tympanic membrane CNX (Inferior parts of EAM and tympanic membrane0

Question 28

Where does the lateral surface of the superior auricle drain to?

Answer 28

Parotid Lymph nodes

Question 29

Where does the cranial surface of the superior half of the auricle drain to?

Answer 29

Mastoid and deep cervical lymph nodes

Question 30

Where does the rest of the auricle including the lobe drain to?

Answer 30

Superficial cervical lymph nodes

Question 31

Where does all lymph from the auricle eventually drain to?

Answer 31

Deep cervical | Thoracic or right lymphatic duct

Question 32

What is involved in otoscopic examination?

Answer 32

Examination of the EAM and tympanic membrane

Question 33

What shape in the EAM in a child?

Answer 33

Short and staight

Question 34

What shape is the EAM in children?

Answer 34

Curved

Question 35

What is the thin part of the tympanic membrane called and where is it found?

Answer 35

Pars flaccida | Superiorly

Question 36

What is the most inwardly depressed part of the tympanic membrane?

Answer 36

Umbo

Question 37

What is the thick part of the tympanic membrane and where is it found?

Answer 37

Pars tensa | Posteroinferiorly

Question 38

What supplies the external surface of the tympanic membrane?

Answer 38

CN V3

Question 39

What supplies the internal surface of the tympanic membrane?

Answer 39

CN IX

Question 40

What does the glossopharyngeal nerve provide sensory innervation to?

Answer 40

``` Middle ear cavity Eustachian tube Nasopharynx Oropharynx Tonsils ```

Question 41

What does the eustachian tube connect?

Answer 41

The tympanic cavity to the wall of the nasopharynx

Question 42

What 3 bones does the middle ear contain?

Answer 42

Malleus Incus Stapes

Question 43

What 2 muscles are found in the middle ear?

Answer 43

Stapedius | Tensor tympani

Question 44

What nerves have branches in the middle ear?

Answer 44

Facial nerve | Glossopharyngeal nerve

Question 45

How do auditory ossicles articulate?

Answer 45

Via synovial joints

Question 46

Where is the epitympanic membrane found?

Answer 46

Superior to tympanic membrane

Question 47

Which bone in the middle ear does not have a muscle attachment?

Answer 47

Incus

Question 48

What is the roof of the tympanic cavity?

Answer 48

Tegmental wall

Question 49

What is the floor of the tympanic cavity?

Answer 49

Jugular wall

Question 50

WHat is the lateral wall of the tympanic cavity?

Answer 50

Membranous wall

Question 51

What is the medial wall of the tympanic cavity?

Answer 51

Labyrinthine wall

Question 52

WHat is the posterior wall of the tympanic cavity?

Answer 52

Mastoid wall

Question 53

What nerve supplies the stapedius muscle?

Answer 53

CN VII

Question 54

What nerve supplies to tensor tympani muscle?

Answer 54

CN V3

Question 55

What is the eustachian tube?

Answer 55

Auditory pharyngotympanic tube

Question 56

Why can tonsilitis mimic ear ache?

Answer 56

Common sensory nerve supply

Question 57

What is the sensory supply to the nasopharynx/Oropharynx?

Answer 57

CN IX

Question 58

What is the sensory supply to the laryngopharynx?

Answer 58

CN X

Question 59

What is the chorda tympani?

Answer 59

A branch of the CN VII

Question 60

What does the chorda tympani supply?

Answer 60

Taste buds to anterior 2/3rds of the tongue | Parasympathetic to submandibular and sublingual salivary glands

Question 61

What does the stapedius do?

Answer 61

Reduced stapes movement to protect the internal ear from excessive noide

Question 62

What does the chorda tympani connect to?

Answer 62

Lingual nerve branch of CN V3

Question 63

What are the 4 muscles of facial expression?

Answer 63

Frontalis Orbicularis oculi Elevator of lips Orbicularis oris

Question 64

Where do muscles of facial expression originate/Insert?

Answer 64

Originate on bone | Insert into superficial fascia

Question 65

What are the 2 parts of CN VIII in the inner ear?

Answer 65

``` Cochlear nerve (hearing) Vestibular nerve (balance) ```

Question 66

Where is the otic capsule found?

Answer 66

Temporal bone

Question 67

What does the otic capsule contain?

Answer 67

Bony labyrinth | Fluid (perilymph) filled spaces inside

Question 68

What is suspended within perilymph of the bony labyrinth?

Answer 68

Membranous labyrinth Communicating sacs and ducts Contains enolymph fluid

Question 69

What are 6 features of the inner ear labyrinths?

Answer 69

``` Superior semicicular canal Lateral semicircular canal Posterior semicircular canal Cupula (apex of spiral) Oval window Round window ```

Question 70

What is the cochlear duct?

Answer 70

A long balloon like structure within the cochlea filled with endolymph

Question 71

How are action potentials from the cochlear duct conducted to the brainstem?

Answer 71

In the cochlear nerve

Question 72

What are the semicircular ducts?

Answer 72

Inter-linked balloon-like structures within the semicircular canals filled with endolymph

Question 73

How are action potentials from the semicircular canals conducted to the brainstem?

Answer 73

Vestibular nerve

Question 74

What stimulates hair cells?

Answer 74

Movement of endolymph

Question 75

What are clusters of hair cells found in?

Answer 75

Regions called maculae

Question 76

What do semicircular ducts detect?

Answer 76

Angular movement change

Question 77

What movement does the saccule detect?

Answer 77

Vertical

Question 78

What movement does the utricle detect?

Answer 78

Horizontal

Question 79

How is sound transmitted?

Answer 79

Sound waves make the tympanic membrane vibrate Vibrations are transmitted through ossicles Base of stapes vibrates in oval window Vibration of stapes created pressure waves in perilymph Hair cells in the cochlea are moved, APs are stimulated and conveyed to brain by cochlear nerve Pressure waves descend and become vibrations again Pressuve waves are dampened at the round window

Question 80

What detect auditory stimuli?

Answer 80

Receptor cells in the organ of corti

Question 81

Where is the organ of corti?

Answer 81

Located on basilar membrane

Question 82

What are the 2 parts of the cochlear canal?

Answer 82

Scala vestibuli | Scala tympani

Question 83

What separates the cochlear canal into 2 parts?

Answer 83

Spiral ligament