Middle & Inner Ear

Question 1

Eustachian tube divided into

Answer 1

Bony part ~ 1.2 cm

Cartilaginous part ~ 2.4 cm

Question 2

Narrowest part of Auditory tube

Answer 2

Isthmus

Question 3

Function of Eustachian tube

Answer 3

To equalise the pressure on both side of Tympanic Membrane

Question 4

Muscle responsible for opening of Eustachian tube

Answer 4

Tensor Veli Palatini Muscle

Assisted by Levator Veli Palatini Muscle

Question 5

Tensor Veli Palatini is also know as

Answer 5

Dilator Tubae Muscle

Question 6

Lateral Wall of Middle Ear ~

Derived from ~

Answer 6

Tympanic Membrane

Derived From 1st Pharyngeal Membrane

Made up of all the 3 germ layers

Question 7

Roof of Middle Ear is Formed By ___________

And is separating Middle Ear from _______

Answer 7

Tegmen tympani ~ thin plate of bone

Separates Middle Ear from Middle Cranial Fossa

Question 8

Floor (Bony plate) of Middle ear is separating from

Floor is pierced by

Answer 8

Internal Jugular Vein

Pierced by Tympanic branch of Glossopharyngeal ~ in turn forms Tympanic Plexus

Question 9

Lower part of anterior wall of Middle ear cavity is relating to

Answer 9

Inter Carotid Artery

Question 10

Upper Part of Anterior wall of Middle Ear Cavity has

Answer 10

2 Bony Canals

1st for Tensor Tympani Muscle

2nd for Auditory Tube

Question 11

Aditus is present in which wall of middle ear cavity

Answer 11

Posterior Wall

Through Aditus Middle ear is communicating with Mastoid Antrum

Question 12

Pyramidal Eminence contains

Answer 12

Stapedial Muscle

Question 13

Structures in Posterior Wall of Middle Ear

Answer 13

Aditus

Pyramidal eminence

Bony canal for Facial Nerve

Question 14

Promontory in the medial wall of middle ear is due to

Answer 14

Basal Turn of Cochlea

Question 15

Tympanic plexus is formed by

Is present over _________

Answer 15

Tympanic branch of IX

+

Caroticotympanic Branch (sympathetic plexus over ICA)

Question 16

Oval window also known as

Answer 16

Fenestra Vestibuli

Question 17

Fenestra Vestibuli is closed by

Answer 17

Foot plate of Stapes

Question 18

Fenestra Cochlea is closed by

Answer 18

Fenestra Cochlea / Round Window

Is closed by Secondary Tympanic Membrane

Question 19

Perilymph is derived from

Answer 19

CSF

Question 20

Endolymph is secreted by

Answer 20

Stria Vascularis of Cochlear Duct

Question 21

List Bony Labyrinth consists of

Answer 21

Cochlea
Vestibule
Semicircular canals

Question 22

Membranous labyrinth present in

Cochlea ~

Semicircular Canals ~

Ventricle ~

Answer 22

Cochlear Duct

Semicircular Duct

Utricle and Saccule

Question 23

Centre part of cochlea is called

Answer 23

Modiolous

The cochlear canal making 2.5-2.75 turns around the Modiolous

Question 24

Osseus spiral lamina coming from the Modiolous ~

extending into the cochlear canal

And divides cochlear canal into

Answer 24

3 Parts;

Scala vestbuli

Scala tympani

Scala media (cochlear duct / membranous labyrinth)

Question 25

Boundaries for Scala Media

Answer 25

Above ~ Vestibular Membrane Below ~ Basilar Membrane

Question 26

At the Apex of Modiolous, the Scala Vestibuli and Scala Tympani communicating with each other is called

Answer 26

Helicotrema

Question 27

Perilymph is communicating with the CSF through

Answer 27

Aqueduct of Cochlea

Question 28

Inner ear infection is spreading to CNS through which opening

Answer 28

Aqueduct of Cochlea

Question 29

Aqueduct of Vestibuli transmit the

Answer 29

Endolymphatic Duct

Question 30

Sensory epithelium present in the cochlear duct for hearing is

Answer 30

Organ of Corti

Question 31

Peripheral fibres of Spiral Ganglion is innervating the

Answer 31

Inner and Outer Hair Cells in Organ of Corti

Question 32

Majority of Peripheral fibres of Spiral Ganglion is innervating the

Answer 32

Inner Hair Cell > Outer Hair Cell

Question 33

Central processes of Spiral Ganglion will form

Answer 33

Cochlear Nerve

Question 34

Describe Auditory Pathway E C O L I M A

Answer 34

E ~ Eighth nerve C ~ Cochlear nucleus O ~ sup. Olivary nucleus L ~ Lateral Leminiscus I ~ Inferior colliculus M ~ Medial geniculate body A ~ Auditory cortex (ant. part of superior temporal gyrus)

Question 35

Semicircular canals opens into vestibule by means of

Answer 35

5 Openings Semicircular duct opens into the Utricle by means of 5 openings

Question 36

Cochlear duct opening into the Saccule by means of

Answer 36

Ductus Reunions

Question 37

Utricle and Saccule joining together and forms

Answer 37

Utriculo-Sacculo Duct Which continue as Endolymphatic Duct Endolymphatic duct is passing through Aqueduct of Vestibuli

Question 38

Dilation in Endolymphatic Duct is forming

Answer 38

Endolymphatic Sac ~ observed between the 2 layers of dura

Question 39

Sensory epithelium present in the Saccule and Utricle is called

Answer 39

Maculae For Static Balance

Question 40

Number of Semicircular Canals

Answer 40

3 ~ Anterior, Posterior and Lateral Anterior and Posterior ~ in vertical axis Lateral ~ in horizontal axis

Question 41

________________ canal is Perpendicular to Long Axis of Petrous Temporal Bone

Answer 41

Anterior Semicircular Canal

Question 42

Posterior Semicircular Canal is ___________ to Long Axis of Petrous Temporal Bone

Answer 42

Parallel

Question 43

Angle between each semicircular canal is

Answer 43

90 Degree

Question 44

The dilated end of semicircular canal is

Answer 44

Ampulla Each semicircular canal has dilated end and normal end

Question 45

What is Crus Commune

Answer 45

One end of anterior semicircular canal joins with one end of posterior semicircular canal Due to which semicircular canals opens into vestibule by means of only 5 openings

Question 46

Sensory Epithelium in the Semicircular Duct(canal) is called

Answer 46

Crista ~ for Kinetic Balance