Ear

Question 1

The external ear consists of what two structures?

Answer 1

auricle and external auditory canal

Question 2

The auricle contains an elastic cartilaginous plate covered by skin and the ear lobe that consists of fat and fibrous tissue. What is its function?

Answer 2

transmit sound from the exterior to the tympanic membrane

Question 3

What is the blood and nerve supply to the auricle?

Answer 3

blood supply: superficial temporal and posterior auricular arteries

nerve supply: great auricular and auriculotemporal nerves

Question 4

What is the blood supply and nerve supply of the external auditory canal?

Answer 4

blood supply: superficial temporal, posterior auricular, and deep auricular arteries

nerve supply: auriculotemporal nerve with vagus nerve

Question 5

Where is the middle ear cavity located and what does it contain?

Answer 5

within petrous part of temporal bone and contains the auditory ossicles, 2 muscles and nerves

Question 6

The middle ear cavity is separated from the external auditory canal by this membrane

Answer 6

tympanic membrane

Question 7

The middle ear cavity communicates with the mastoid air cells via the ____ and ____ and with the pharynx via the ____ ____

Answer 7

aditus; antrum; auditory tube

Question 8

The middle ear cavity lining is innervated by what nerve?

Answer 8

glossopharyngeal

Question 9

What nerve passes through the floor (jugular wall) of the middle ear cavity?

Answer 9

tympanic nerve (branch of glossopharyngeal)

Question 10

What innervates the tympanic membrane?

Answer 10

auriculotemporal nerve, twig from vagus nerve, the tympanic plexus

Question 11

What is the apex of the depression (umbo) of the tympanic membrane attached to?

Answer 11

tip of the handle of the malleous

Question 12

The tympanic membrane has a cone of light which is a reflection of light anteroinferior from the umbo, seen using an otoscope. Explain the clinical correlate associated with this

Answer 12

disease, particularly middle ear effusion or otitis media can change the look of the cone of light

Question 13

The anterior wall of the middle ear cavity separates the middle ear from what artery?

Answer 13

ICA

Question 14

Which wall of the middle ear cavity contains the opening for the auditory tube?

Answer 14

anterior wall

Question 15

In the anterior wall, superiomedially, the ____ ____ pierces the edge to attach to the malice; inferolaterally, the ____ ____ nerve exits the middle ear

Answer 15

tensor tympani; chorda tympani

Question 16

The posterior wall of the middle ear cavity separates the middle ear from ___ ____ cells

Answer 16

mastoid air

Question 17

In regards to the posterior wall, the ____ muscle is found inside a small conical projection, the pyramid, where its tendon pierces the apex of the pyramid

Answer 17

stapedius

Question 18

In regards to the posterior wall, the prominence for the canal of the ____ nerve continues here from the medial wall and distributes the nerve to stapedius and the chorda tympani

Answer 18

facial

Question 19

The three auditory ossicles traverse the middle ear cavity, transmitting the _____ of the tympanic membrane to the ____ window of the inner ear

Answer 19

vibrations; oval

Question 20

What nerve courses on the medial surface of the root of the handle of the malleous

Answer 20

chorda tympnai

note: above tensor tympani

Question 21

The incus has a body that articulates with the head of the _____ and a long process that projects downward, bends medially, forming the lenticular process that articulates with the ____

Answer 21

malleous; stapes

Question 22

The stapes has a head that articulates with the ____. It has a neck, two limbs, and an ovoid base, which fits over the ____ window and its membrane.

Answer 22

incus; oval

Question 23

What are the two muscles in the middle ear that work to dampen excessive movements of the ossicles that are produced by high amp vibrations of the tympanic membrane created by loud sounds?

Answer 23

tensor tympani

stapedius

Question 24

What innervates Tensor tympani?

Answer 24

mandibular nerve

Question 25

What innervates stapedius?

Answer 25

facial nerve

Question 26

The tympanic nerve is a branch of the _____ nerve that enters the middle ear via the floor, while chorda tympani is a branch of the ___ nerve that pierces the posterior wall

Answer 26

glossopharyngeal; facial

Question 27

The preganglionic parasympathetic fibers of the tympanic nerve join to form the ____ ____ nerve to then synapse in the otic ganglion

Answer 27

lesser petrosal

Question 28

After passing through the facial canal along the medial and posterior walls of the middle ear cavity, the facial nerve gives off these three nerves

Answer 28

greater petrosal, nerve to stapedius, chorda tympani

Question 29

True or false? The facial nerve never enters the middle ear, but is intimately related

Answer 29

true

Question 30

The cochlear labyrinth of the inner ear communicates with the _____ space superior to the jugular foramen via the cochlear aqueduct

Answer 30

subarachnoid

Question 31

The vestibular membranous labyrinth of the inner ear communicates with the ______ ___ via a duct in the vestibular aqueduct

Answer 31

endolymphatic sac

Question 32

In regards to the cochlea, the scala vestibuli begins at the membrane of the ____ window and spirals to the apex; the scala tympani begins at the apex and spirals to the ___ window with its thin, flexible membrane

Answer 32

oval; round

Question 33

The two chambers formed by the scala vestibuli and scala tympani communicate at the apex via a narrow slit called the _____, which is filled with ____

Answer 33

helicotrema; perilymph

Question 34

What is the cochlear duct filled with?

Answer 34

endolymph

Question 35

Where is the spiral organ (of corti) found?

Answer 35

cochlear duct

Question 36

After synapsing with the hair cells of the spiral organ, the sensory fibers converge to form the ____ ganglion, then the ____ nerve as part of the vestibulocochlear nerve

Answer 36

spiral; cochlear

Question 37

Lesions in the external auditory canal may cause nausea and vomiting. Why?

Answer 37

Vagus nerve

Question 38

Interruption in the lateral lemniscus in the brain stem results in what?

Answer 38

partial deafness on the contralateral side

Question 39

The utricle and saccule found in the vestibule of the bony labyrinth detect what?

Answer 39

head tilt and translational accelerations

Question 40

The lateral, anterior, and posterior semicircular canals detect what?

Answer 40

rotational accelerations

Question 41

A patient comes in with vestibular symptoms, ringing in the ear, ipsilateral deafness, weakness/paralysis of the facial muscles, loss of taste, and lack of glandular secretions. What is the most likely diagnosis?

Answer 41

vestibular schwannoma (acoustic neuroma)