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Flashcards in Ear Deck (41)
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1
Q

The external ear consists of what two structures?

A

auricle and external auditory canal

2
Q

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?

A

transmit sound from the exterior to the tympanic membrane

3
Q

What is the blood and nerve supply to the auricle?

A

blood supply: superficial temporal and posterior auricular arteries nerve supply: great auricular and auriculotemporal nerves

4
Q

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

A

blood supply: superficial temporal, posterior auricular, and deep auricular arteries nerve supply: auriculotemporal nerve with vagus nerve

5
Q

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

A

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

6
Q

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

A

tympanic membrane

7
Q

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

A

aditus; antrum; auditory tube

8
Q

The middle ear cavity lining is innervated by what nerve?

A

glossopharyngeal

9
Q

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

A

tympanic nerve (branch of glossopharyngeal)

10
Q

What innervates the tympanic membrane?

A

auriculotemporal nerve, twig from vagus nerve, the tympanic plexus

11
Q

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

A

tip of the handle of the malleous

12
Q

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

A

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

13
Q

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

A

ICA

14
Q

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

A

anterior wall

15
Q

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

A

tensor tympani; chorda tympani

16
Q

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

A

mastoid air

17
Q

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

A

stapedius

18
Q

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

A

facial

19
Q

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

A

vibrations; oval

20
Q

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

A

chorda tympnai note: above tensor tympani

21
Q

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 ____

A

malleous; stapes

22
Q

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.

A

incus; oval

23
Q

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?

A

tensor tympani stapedius

24
Q

What innervates Tensor tympani?

A

mandibular nerve

25
Q

What innervates stapedius?

A

facial nerve

26
Q

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

A

glossopharyngeal; facial

27
Q

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

A

lesser petrosal

28
Q

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

A

greater petrosal, nerve to stapedius, chorda tympani

29
Q

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

A

true

30
Q

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

A

subarachnoid

31
Q

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

A

endolymphatic sac

32
Q

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

A

oval; round

33
Q

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 ____

A

helicotrema; perilymph

34
Q

What is the cochlear duct filled with?

A

endolymph

35
Q

Where is the spiral organ (of corti) found?

A

cochlear duct

36
Q

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

A

spiral; cochlear

37
Q

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

A

Vagus nerve

38
Q

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

A

partial deafness on the contralateral side

39
Q

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

A

head tilt and translational accelerations

40
Q

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

A

rotational accelerations

41
Q

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?

A

vestibular schwannoma (acoustic neuroma)