Anatomy of the Ear

Question 1

Organ of balance; within the inner ear; consists of the Semicircular canals, Utricle and Saccule

Answer 1

Vestibular Apparatus

Question 2

Part of Vestibular Apparatus; used for perception of ANGULAR acceleration (rotation of head)

Answer 2

Semicircular canals

Question 3

Parts of Vestibular Apparatus; used for perception of LINEAR acceleration

Answer 3

Utricle & Saccule

Question 4

The lateral 1/3rd of the External Acoustic Meatus is (bony/cartilaginous) and is lined with skin that produces cerumen (earwax)

Answer 4

Cartilaginous

Question 5

The medial 2/3rds of the External Acoustic Meatus is (bony/cartilaginous) and is lined with skin that is continuous with the tympanic membrane

Answer 5

Bony

Question 6

What three cranial nerves contribute to innervating the Auricle and Ear Canal

Answer 6

Trigeminal (V3)
Vagus (CN X)
Facial (CN VII)

Question 7

Which cranial nerve innervates the central portion of the Auricle and the External Acoustic Meatus

Answer 7

Vagus (CN X)

Question 8

Small opening in the posterior wall of the Middle Ear; leads to a cavity within the mastoid process

Answer 8

Auditus

Question 9

The _____________ nerve passes through a bony canal along the posterior wall of the Middle Ear

Answer 9

Facial

Question 10

A rounded hollow prominence of the medial Middle Ear covered by a nerve plexus; separates middle ear from the inner ear; has the tympanic plexus over it and two windows (oval and round)

Answer 10

Promontory

Question 11

The Tympanic Plexus in the Middle Ear comes from which cranial nerve and therefore provides sensory innervation from middle ear/eustachian tube?

Answer 11

Glossopharyngeal (CN IX)

Question 12

Patients with middle ear infections feel the pain via what nerve?

Answer 12

Glossopharyngeal nerve (Tympanic Plexus)

Question 13

What are the 3 ossicles of the Middle Ear (in order)

Answer 13

Malleus
Incus
Stapes

Question 14

What are the 2 muscles in the Middle Ear that dampen movements of ossicles to lessen loud sound transmission in order to prevent damage?

Answer 14

Tensor Tympani (at eardrum)
Stapedius (at stapes)

Question 15

Muscle of Middle ear; innervated by Trigeminal (V3); lessens damage from loud sounds by “tensing” the eardrum via attaching to the Handle of the Malleus

Answer 15

Tensor Tympani

Question 16

Muscle of the Middle Ear; innervated by the Facial nerve; dampens vibrations of the Stapes at the Oval Window

Answer 16

Stapedius

Question 17

Small branch of the Facial nerve that passes THROUGH the Middle Ear cavity on it’s way to the oral cavity; courses between the Malleus and Incus; Swelling and compression of this nerve during URIs can dampen taste

Answer 17

Chorda Tympani

Question 18

Central depression of the Tympanic Membrane

Answer 18

Umbo

Question 19

Reflection of light from the Otoscope at the anteroinferior portion of the Tympanic Membrane (due to the membrane’s orientation)

Answer 19

Cone of Light

Question 20

Thin portion of the Tympanic Membrane above the Handle of the Malleus

Answer 20

Pars Flaccida (flaccid)

Question 21

Thick portion of the Tympanic Membrane that makes the majority

Answer 21

Pars Tensa (tense)

Question 22

Contents of the Bony Labyrinth of the Inner Ear

Answer 22

Cochlea
Vestibule
Semicircular Canals

Question 23

The ____________________ labyrinth is a series of ducts/sacs suspended WITHIN the bony labyrinth and filled with _____________________

Answer 23

Membranous; endolymph (similar to intracellular fluid)

Question 24

The membranous labyrinth consists of what 3 inner ear apparati

Answer 24

Cochlear duct
Utricle/Saccule
Semicircular ducts

Question 25

Specialized structures within the Utricle and Saccule to detect LINEAR movements

Answer 25

Maculae (have hair cells)

Question 26

Signals detected by the Utricle, Saccule and Semicircular Ducts in the Inner Ear are conveyed via the ____________________ nerve

Answer 26

Vestibular (CN VIII)

Question 27

Swelling at the base of each semicircular duct; contains special sensory structures called crista

Answer 27

Ampulla

Question 28

Special sensory structure in the Ampulla of the Semicircular ducts; detects the movement of the surrounding endolymph during rotational movement of the head

Answer 28

Crista

Question 29

What chamber(s) of the Cochlea have perilymph

Answer 29

Scala Vestibuli | Scala Tympani

Question 30

What chamber(s) of the Cochlea has endolymph

Answer 30

Scala media (Cochlear duct)

Question 31

Membrane that separates the Scala Vestibuli and Cochlear Duct

Answer 31

Vestibular membrane

Question 32

Membrane that separates the Cochlear Duct and the Scala Tympani

Answer 32

Basilar membrane

Question 33

The Scala Vestibuli and Tympani are continuous at the tip of the Cochlea, called the...

Answer 33

Helicotrema

Question 34

Transmission of sound waves goes along the perilymph of _______ and displaces the (vestibular/basilar) membrane to manipulate the Organ of Corti within __________.

Answer 34

Basilar; scala media (cochlear duct)

Question 35

Nerve endings in the Organ of Corti transmits impulses to the CNS via _______ nerve

Answer 35

cochlear nerve (CN VIII)

Question 36

The pressure wave traveling through the scala tympani eventually dissipates into _______ via _______

Answer 36

tympanic cavity (middle ear); round window