Ear

Question 1

The external ear and middle ear
are mainly concerned with the transfer of sound to the internal ear, which
contains the organ for equilibrium as well as for hearing.

Question 2

The tympanic
membrane separates the _____ from the _____.
_______ joins the middle ear to the nasopharynx.

Answer 2

external ear from middle ear.
pharyngotympanic
tube

Question 3

The external ear consist of

Answer 3

Pinnia, external aucustic meatus, tympanicmembrane

Question 4

The main nerves supplying the skin of the auricle are ___&____

Answer 4

the great auricular nerve and the auriculotemporal nerve.

Question 5

The skin of the concha( the opening in the ear) is primarily innervated by _____.
Its a minor innervation

Answer 5

the auricular branch of the vagus nerve, with a minor contribution from the facial nerve

Question 6

EAM
The lateral 1/3 is catelegenous
The medial two thirds of the meatus is bony and lined with thin
skin that is continuous with the external layer of the tympanic membrane

Question 7

ceruminous and sebaceous glands in the subcutaneous tissue of the cartilaginous
part of the meatus produce cerumen EARWAX

Question 8

The tympanic
membrane is covered with thin skin externally and mucous membrane of the
middle ear internally

Question 9

the tympanic membrane has a slight curve towards the outer ear, and it has a small dip in the center called the umbo. The umbo is like the highest point of a cone, and the central axis of the tympanic membrane passes right through it,

Question 10

The tympanicmembrane consist of

Answer 10

Par Flaccida: This is the thin, flaccid part of the membrane that is located superior (upper) to the lateral process of the malleus. It lacks the radial and circular fibers present in the rest of the membrane. It forms the lateral wall of the superior recess of the tympanic cavity.

Pars Tensa: This is the thicker part of the membrane that is found in the remainder of the membrane. It contains radial and circular fibers, which provide structural support and contribute to its tensile strength

Question 11

Superior and anterior walls of EAM and upper two-thirds of the external surface of TM
Innervated by the _____
Posterior and inferior wallsof EAM , and lower one-third of the external surface of TM:
Innervated by the ______
Internal surface of TM
Innervated by the ______

Answer 11

auriculotemporal nerve (branch of trigeminal nerve, CN V3).

auricular branch of the vagus nerve (CN X).

glossopharyngeal nerve (CN IX).

Question 12

The middle ear lies within the ____ bone, and extends from the tympanic membrane to the lateral wall of the inner ear.

Answer 12

temporal bone

Question 13

The main function of the middle ear is

Answer 13

to transmit vibrations from the tympanic membrane to the inner ear via the auditory ossicles.

Question 14

The ___&___ partially extend upwards into the epitympanic recess.

Answer 14

malleus and incus

Question 15

What’s tympanic cavity and epi tympanic recess

Answer 15

a space superior to the tympanic cavity, which lies next to the mastoid air cells

Question 16

The _____ is the largest ossicle in d ear

Answer 16

malleus

Question 17

What’s the buffer system of d middle ear

Answer 17

The mastoid air cells are located posterior to epitympanic recess. They are a collection of air-filled spaces in the mastoid process of the temporal bone
The mastoid air cells act as a ‘buffer system‘ of air – releasing air into the tympanic cavity when the pressure is too low.

Question 18

There are two muscles which serve a protective function in the middle ear, they are
And how do they function

Answer 18

tensor tympani and stapedius

They contract inresponseto loud noise, inhibiting the vibrations of the malleus, incus and stapes

Question 19

What’s acoustic reflex

Answer 19

contraction in response to loud noise, inhibiting the vibrations of the malleus, incus and stapes, and reducing the transmission of sound to the inner ear. This action is known as the acoustic reflex.

Question 20

The tensor tympani and stapes orginates from

Answer 20

The tensor tympani originates from the auditory tube and attaches to the handle of malleus, pulling it medially when contracting

The stapedius muscle attaches to the stapes, and is innervated by the facial nerve.

Question 21

______ equalisethe pressure of the middle ear to that of the external auditory meatus.

Answer 21

The auditory tube (eustachian tube)

Question 22

What’s the auditory tube

Answer 22

The auditory tube (eustachian tube) is a cartilaginous and bony tube that connects the middle ear to the nasopharynx

Question 23

The neck of the malleus lies against the flaccid part of the tympanic
membrane, and the handle of the malleus is embedded in the tympanic
membrane, with its tip at the umbo; thus, the malleus moves with the membrane

Question 24

___ part of the ear is responsible for balance

Answer 24

Inner part

Question 25

The inner ear can be divided into

Answer 25

Bony and membranous labyrinth

Question 26

The bony labyrinth consists of
And is lined with

Answer 26

Vestibule, cochlear,3 semi circular canal
Lined with periosteom containing perilymph

Question 27

The Membranous labyrinth consists of
And is filled with

Answer 27

It consists of the cochlear duct, semi-circular ducts, utricle and the saccule. The membranous labyrinth is filled with fluid called endolymph

Two parts of the membranous labyrinth; thesacculeandutricle, are located within the vestibule.

Question 28

The inner ear has ____ openings into the middle ear

Answer 28

2
Oval and round

Theoval windowlies between themiddle earand the vestibule

whilst the round window separates the middle ear from the scala tympani (part of the cochlear duct).

Question 29

The bony labyrinth is a series of bony cavities within the petrous part of the temporal bone.

Question 30

The vestibule is the central part of the bony labyrinth. It is separated from the middle ear by the oval window, and communicates anteriorly with the __$ and posteriorly with the ____

Answer 30

cochlea and with semi-circular canals.

Question 31

the auditory part of the inner ear is

Answer 31

Cochlear duct in membranous labyrinth

Question 32

The cochlea houses the cochlea duct of the membranous labyrinth – the auditory part of the inner ear. It twists upon itself around a central portion of bone called the modiolus, producing a cone shape which points in an anterolateral direction. Branches from the cochlear portion of the vestibulocochlear (VIII) nerve are found at the base of the modiolus.

Question 33

The presence of the _____ creates two perilymph-filled chambers above and below in cochlear
Which are

Answer 33

cochlear duct

Scala vestibuli: Located superiorly to the cochlear duct. As its name suggests, it is continuous with the vestibule

Scala tympani: Located inferiorly to the cochlear duct. It terminates at the round window.

Question 34

There are ____ semi-circular canals
Which are

Answer 34

3
anterior, lateral and posterior.

Question 35

What part of the bony and membranous labyrinth is responsible for balance

Answer 35

The semi-circular ducts, which are responsible for balance (along with the utricle and saccule).

Question 36

Membranous Labyrinth consists of

Answer 36

cochlear duct, three semi-circular ducts, saccule and the utricle.

Question 37

The cochlear duct is situated within the cochlea and is the organ of hearing.
vestibular apparatus consists of

Answer 37

The semi-circular ducts, saccule and utricle are the organs of balance (also known as the vestibular apparatus).

Question 38

Write a short note on the inner ear fluids

Answer 38

The inner ear fluid, also known as the endolymph and perilymph, is a vital component of the human auditory and vestibular systems. It plays a crucial role in maintaining balance, spatial orientation, and hearing.
•Endolymph is found within the membranous labyrinth, which includes the cochlea (responsible for hearing) and the vestibular system (involved in balance and spatial orientation).The endolymph is crucial for transmitting sound vibrations and mechanical signals to the sensory cells within the cochlea and vestibular system.

•perilymph surrounds the membranous labyrinth and fills the bony labyrinth. It is similar in composition to cerebrospinal fluid, Perilymph helps protect the delicate structures of the inner ear, provides mechanical support, and facilitates the transmission of sound waves from the outer ear to the cochlea.

Question 39

The membranous labyrinth is

Answer 39

The membranous labyrinth is a continuous system of ducts filled withendolymph.

Question 40

The saccule and utricle are two membranous sacs located in the _____

Answer 40

vestibule

Question 41

The utricle is the larger of the two, receiving the three semi-circular ducts. The saccule is globular in shape and receives the cochlear duct.

Question 42

Explain the mechanism of hearing

Answer 42

1, Sound waves entering the external ear strike the tympanic
membrane, causing it to vibrate.
2, Vibrations initiated at the
tympanic membrane are transmitted through the ossicles of the
middle ear and their articulations.
3, The base of the stapes
vibrates with increased strength and decreased amplitude in the
oval window.
4, Vibrations of the base of the stapes create pressure waves in the perilymph of the scala vestibuli.
5,Pressure waves in the scala vestibuli cause displacement of the
basilar membrane of the cochlear duct
6.Movement of the basilar membrane
bends the hair cells of the spiral organ. Neurotransmitter is
released, stimulating action potentials conveyed by the cochlear
nerve to the brain.
6, Vibrations are transferred across the
cochlear duct to the perilymph of the scala tympani.
7, Pressure
waves in the perilymph are dissipated (dampened) by the
secondary tympanic membrane at the round window into the air
of the tympanic cavity.