Ear

Question 1

What is the function of the ear?

Answer 1

Hearing & balance

Question 2

What are the three components of the ear?

Answer 2

External, middle, and internal (neuro 2023)

Question 3

What is the external ear comprised of?

Answer 3

Auricle (pinna) and external auditory meatus

Question 4

What tissue is the external ear comprised of?

Answer 4

Elastic cartilage

Question 5

What does the auricle do?

Answer 5

Assist in capturing sound -> numerous folds & depressions

Question 6

How does the auricle go?

Answer 6

Funnels to external auditory meatus

Question 7

What is cauliflower ear? How does it occur?

Answer 7

Hematoma within layers, which causes avascular necrosis and is fibrotic
Occurs primarily to fights due to repetitive blunt trauma

Question 8

What is the blood supply of the external ear?

Answer 8

Superficial temporal artery, posterior auricular artery, deep auricular artery (from maxillary)

Question 9

What is the venous drainage of the external ear?

Answer 9

Follows pattern of arteries

Question 10

What is the lymph drainage of the external ear?

Answer 10

Parotid (anterior + external acoustic meatus), mastoid (posterior), and deep cervical nodes

Question 11

What is the GSA innervation of the external ear?

Answer 11

Auriculotemporal nerve (CN V)
Lesser occipital nerve (C2, C3)
Great auricular nerve (C2, C3)
Auricular branch of CN X
CN VII
CN IX

Question 12

What is the external auditory meatus?

Answer 12

Extends from the deepest part of concha to the tympanic membrane (~ 1 inch)
Lateral 1/3 is cartilaginous, medial 2/3 is bony (temporal bone)
Covered in skin -> contains hair follicles and ceruminous glands (ear wax)

Question 13

What is the innervation of external auditory meatus?

Answer 13

1. Auriculotemporal nerve
2. CN X (auricular branch)
3. CN VII
4. CN IX

Question 14

What is the purpose of the tympanic membrane?

Answer 14

Separates EAM from middle ear
Lateral surface angled anteroinferior (~55*)

Question 15

How to use cone of light?

Answer 15

Allows you to see the side of the ear you are looking at

Question 16

What is the connective tissue lined with?

Answer 16

Laterally -> connective tissue
Medially -> mucous membrane

Question 17

The lateral surface of tympanic membrane innervation

Answer 17

3/4 auriculotemporal nerve, 1/4 CN X, some from CN VII

Question 18

The medial surface of tympanic membrane innervation

Answer 18

CN IX (tympanic nerve)

Question 19

What is impacted in Swimmer’s ear?

Answer 19

Auriculotemporal nerve, vagus nerve

Question 20

Where would lymphadenopathy be for Swimmer’s ear?

Answer 20

Parotid gland

Question 21

How is the middle ear separated from the external auditory meatus?

Answer 21

Tympanic membrane

Question 22

Space within the temporal bone is lined with…

Answer 22

Mucous membrane

Question 23

What is the function of the middle ear?

Answer 23

Transmit vibrations of tympanic membrane to inner ear via three ossicles -> malleus, incus, stapes

Question 24

What are the boundaries of the middle ear?

Answer 24

Lateral -> tympanic membrane + temporal bone
Medial -> lateral wall of inner ear (promontory + tympanic plexus), prominences of lateral semicircular canal and facial canal
Anterior -> temporal bone adjacent to carotid canal
Posterior -> adjacent to mastoid air cells

Question 25

What are the openings of the middle ear?

Answer 25

1. Pharyngotympanic tube 2. Aditus to mastoid antrum 3. Oval and round windows

Question 26

What can break through membrane of middle ear?

Answer 26

Infections

Question 27

What opening communicates with pharyngotympanic tube?

Answer 27

Nasopharynx

Question 28

What opening communicates with mastoid antrum?

Answer 28

Aditus to mastoid antrium

Question 29

What are the ossicles?

Answer 29

Mallelus, incus, and stapes

Question 30

How do the ossicles articulate?

Answer 30

True synovial joints

Question 31

How is the malleus attached?

Answer 31

Tympanic membrane via handle

Question 32

How is the stapes attached?

Answer 32

Oval window via base

Question 33

What is otoscleosis?

Answer 33

Abnormal growth around bone ossicles, usually involving stapes -> causes productive hearing loss

Question 34

What is the key finding of the mallelus?

Answer 34

Ice cream cone

Question 35

What are the two muscles in the middle ear?

Answer 35

Stapedius (CN VII) and tensor tympani (CN V3) Responsible for protection against loud noise

Question 36

What is hyperacusis?

Answer 36

Increased senisitvity to sound -> caused by injury to CN VII

Question 37

What nerves run through the middle ear?

Answer 37

Tympanic nerve (CN IX) and lesser petrosal nerve (CN IX)

Question 38

What info does lesser petrosal nerve?

Answer 38

GVE + GVE

Question 39

Where does chorda tympani course?

Answer 39

Medial to handle of mallelus

Question 40

What information does the chorda tympani carry?

Answer 40

SVA, GVE, GVA

Question 41

The pharyngotympanic tube is fixed...

Answer 41

Between greater wing of sphenoid and petrous part of temporal bone

Question 42

What is the innervation of pharygotympanic tube?

Answer 42

Tympanic plexus (CN IX), pharyngeal branches from PPG

Question 43

What is otitis media? Who is it common in?

Answer 43

Middle ear infection, in younger children Nerves at risk: chorda tympani, tympanic nerve, internal carotid

Question 44

How do you place tympanostomy?

Answer 44

Inferior aspect in order to avoid chorda tympani

Question 45

What is mastoiditis?

Answer 45

Inflammation of mastoid due to recurrent middle ear infection

Question 46

What is the lymphatic drainage of middle ear?

Answer 46

* (External Meatus [otitis externa, infected piercing] – parotid > jugulodigastric > mastoid) * Middle Ear [otitis media] – parotid > jugulodigastric * Pharyngotympanic Tube – retropharyngeal

Question 47

What is the venous drainage of middle ear?

Answer 47

To transverse and superior petrosal sinuses, pterygoid venous plexus

Question 48

What is the arterial supply of middle ear?

Answer 48

1. Maxillary a. 2. Posterior auricular/occipital aa. 3. Middle meningeal a. 4. Ascending pharyngeal a. 5. Tympanic branch from internal carotid a.