Ear

Question 1

External Ear consists of

Answer 1

• Auricle
• External Auditory meatus

Question 2

Gland Unique to External Auditory meatus

Answer 2

Ceruminous Gland

Question 3

function of cerumen

Answer 3

Protective function, antimicrobial Effect

Question 4

Layers of Ear drum

Answer 4

• Outer layer: Keratinized stratified squamous epithelium
• Inner layer: Simple cuboidal Epithelium
• Middle layer: Dense CT, with outer radial collagen fibers, inner Circular collagen fibers

Question 5

Name of part of tympanic membrane which is flacid, and its location

Answer 5

Shrapnel’s membrane (pars flaccida), located at Antero-superior quadrant

Question 6

Function of External Ear

Answer 6

collection of sound waves

Question 7

Lining of tympanic cavity (middle ear)

Answer 7

Simple cuboidal Epithelium resting on lamina propria adherent to periosteum

Question 8

Enumerate Contents of middle ear

Answer 8

3 Bones:
* Malleus
* Incus
* Stapes

2 Muscles:
* Tensor tympani
* Stapedius

1 Nerve: Chorda tympani

Question 9

footplate of stapes fits into

Answer 9

Oval window of inner ear

Question 10

Function of Middle ear

Answer 10

Amplification of mechanical Vibrations

Question 11

Importances of muscles of middle ear

Answer 11

• Regulation of sound conduction
• Reflex contration during loud sounds to prevent damage if receptors

Question 12

Auditory tube connects

Answer 12

Middle ear with Nasopharynx

Question 13

Function of auditory tube

Answer 13

Equalize pressure on both sides of the drum

Question 14

Auditory tube is lined with

Answer 14

Pseduostratified columnar ciliated epithelium

Question 15

Infection spreading from Nasopharyx to Middle ear through auditory tube may cause

Answer 15

Otitis Media

Question 16

Cochlea spirals ….. turns around Modiolus

Answer 16

2 1/2

Question 17

Modiolus contains

Answer 17

• Blood vessels
• Nerve fibers
• Cell bodies of neurons of Spiral Ganglia

Question 18

Extension of Modiolus into lumen of cochlear tube is called

Answer 18

Spiral Lamina

Question 19

thickening on outer bony wall of cochlear tube is called

Answer 19

Spiral Ligament

Question 20

membrane stretching between Spiral Lamina & spiral Ligament is called

Answer 20

Basilar membrane

Question 21

Organ of corti Lies on

Answer 21

Basilar membrane

Question 22

Vestibular Membrane forms

Answer 22

roof of cochlear duct

Question 23

Basilar and vestibular membranes divide cochlear tube into

Answer 23

3 parts:
* Scala vestibuli: above vestibular membrane, containing perilymph
* Cochlear duct: has Vestibular membrane as roof & Basilar membrane as floor, it contains Endolymph
* Scala Tympani: Below Basilar membrane, contains **Perilymph **

Question 24

Both scala vestibuli & scala tympani are lined with

Answer 24

simple Squamous epithelium

Question 25

Difference between Vestibular Membrane & basilar Membrane

Answer 25

* vestibular membrane is lined with simple sqamous mesothelium on both sides * Basilar membrane is lined with simple squamous mesothelium on 1 side

Question 26

outer wall of cochlear duct is made up of

Answer 26

**Stria vascularis**: **modified epithelium** responsible for **formation of endolymph**, it consists of **Capillaries and cells with basal infoldings**

Question 27

Cells that form boundaries of tunnel of corti

Answer 27

Inner & outer pillar cells

Question 28

cells that form direct support with hair cells of organ of corti

Answer 28

Inner & outer phalangeal cells

Question 29

difference between inner & outer phalangeal cells

Answer 29

* Inner phalangeal cell forms **1 row** of cells only, and **completely surrounds** the hair cell * Outer phalangeal cells form **3-4 rows** of cells, they form **Cup shape** to give out **phalanx** to support the hair cell (basal 1/3)

Question 30

tip of stereocilia of hair cells is embedded in

Answer 30

tectorial Membrane

Question 31

Bases of hair cells contain

Answer 31

Bipolar nerve cells and their dendrites

Question 32

otolithic membrane of vestibule contains

Answer 32

CaCO3

Question 33

Hair cells of macula of Vestibule are ........ mechanoreceptor hair cells

Answer 33

Type 1 & 2

Question 34

Hair cells of vestibule have

Answer 34

Many sterocilia and one true cilium (kinocilium)