Ear Test Three

Question 1

Describe the external auditory meatus.

Answer 1

Outer 1/3 of the ear is composed of elastic cartilage and the inner 2/3 is composed of bone, lined with stratified squamous epithelium and ceruminous and sebaceous glands.

Question 2

What kind of cartilage makes up the Auricle?

Answer 2

Elastic cartilage

Question 3

Describe the Tympanic membrane.

Answer 3

Separates the external auditory canal from the middle ear, the core is formed from vascular and innervated CT, internal surface is cuboidal epi.

Question 4

Identify

Answer 4

1. Integument
2. Hair follicle
3. Elastic cartilage
4. Blood Vessels

Question 5

Identify

Answer 5

Elastic cartilage of external ear

Question 6

What are the auditory ossicles in order from external to innermost?

Answer 6

1. Malleus: attaches to the tympanic membrane articulates with the incus
2. Incus: an intermediate between the stapes and malleus
3. Stapes: Shaped like a stirrup and inserts onto the oval window

Question 7

What is the oval window?

Answer 7

It opens up into the scala vestibuli

Question 8

What is the round window?

Answer 8

Membrane covered region at the end of the scala tympani

Question 9

What are the regions of the inner ear?

Answer 9

Bony Labyrinth

Membranous Labyrinth

Vestibular organ

Auditory organ

Question 10

Describe the bony labyrinth.

Answer 10

System of canals and chambers in the temporal bone filled with high sodium perilymphh.

Consists of:

• Semicircular canals
• Cochlea
• Scala vestiubuli
• Scala tympani

Question 11

Describe the membranous labyrinth.

Answer 11

Filled with high potassium content endolymph

Complex system of membranous structures embedded within the chambers of the bony labyrinth.

Question 12

What are the vestibular organs?

Answer 12

Patches of sensory structures that respond to changes in position consisting of the maculae of saccule and utricle and the cristaea ampullaris of semicircular canals

Question 13

Describe the maculae of the saccule and utricle.

Answer 13

Epithelium is columnar supporting cells

Also contains vesibular hair cells in contact with afferent nerve endings:

• Numerous stereocilia which are non motile
• Single kinocilium which is very long

Question 14

What is the Otolithic membrane?

Answer 14

gelatinous layer part of the maculae of saccule and utricle containing calcium carbonate crystals called otoliths. Stereociliar of vestibular hair cells are embedded in this. Movements of head displaces the membrane and causes a sensory impulse.

Question 15

Describe the Cristae Ampullares of semicircular ducts.

Answer 15

Columnar epithelium supportingcells

Hair cells depend on fluid movement similar to those of the Maculae

Has the Cupula similar to the otolithic membrane, but without the otoliths. Movement of the head creates shear foces between the semicircular canals and the fluid displacing the cupula causing stereocilia to bend

Question 16

Scala media/Cochlear duct divides the bony cochlea into ____&_____.

Answer 16

Scala vestibuli and Scala Tympani

Question 17

Vestibular membrane forms the _______.

Answer 17

Roof of the duct

Question 18

Stria vascularis forms the ___ and participates in the formation of the _____.

Answer 18

Lateral aspect of the duct and Endolymph (high K content)

Question 19

The basilar membrane forms the _____.

Answer 19

Floor of the duct

Question 20

Where is the organ of corti found?

Answer 20

On the basilar membrane

Question 21

Identify.

Answer 21

1. Scala vestibuli
2. Vesibular membrane
3. Cochlear duct (scala media)
4. Stria vascularis
5. Organ of Cotri
6. Basilar membrane
7. Scala tympani

Question 22

Idenitfy 0-5.

Answer 22

0. Scala vestibuli with perilymph
1. Vestibular membrane
2. Internal spiral tunnel of cochlear duct
3. Tectorial membrane
4. Inner hair cells
5. Inner tunnel

Question 23

Identify 6-10.

Answer 23

6. Cochlear duct with endolymph
7. Stria vascularis
8. Outer hair cells
9. Basilar membrane
10. Scala tympani with perilymph