Lecture 17

Question 1

What are the structures that will comprise the external ear?

Answer 1

auricle and the pinna

Question 2

What material is the vertical portion of the external ear canal composed of?

Answer 2

Cartilage

Question 3

What material is the horizontal portion of the external ear canal composed of?

Answer 3

Bone

Question 4

What is the function of the auditory tube?

Answer 4

Air supply to the middle ear

Question 5

Name the following structures:

6+ 7: Name type of connective tissue present

Answer 5

1. scapha
2. conchal cartilage
3. annular cartiladge
4. temporal bone
5. Tympanic membrane
6. cartiladge
7. osseus portion

Question 6

What is the function of the petrous portion of the temporal bone?

Answer 6

The petrous portion of the temporal bone is the thickest region of the bone within the body the main function of this component of bone is to protect the middle ear cavity.

Question 7

For the following image:

1. Name structure one

2 + 3. Mediala and lateral border of what

4. Name the floppy cartilage structure

Answer 7

1. Tragus
2. Lateral border of the helix
3. Medial border of the helix
4. Scapha

Question 8

What is the primary function of the tensor tympani and the stapedius muscles?

Answer 8

They are able to dampen down the extent of the vibrations within the ear cavity

Question 9

How is the tension in the tympanic membrane adjusted?

Answer 9

Movement of the malleus in the tympanic membrane allows for the adjustment of the tension in the tympanic membrane

Question 10

Where is the footplate of the stapes? What is its function?

Answer 10

The footplate of the stapes is located in the oval window. The main function of this structure is to transfer vibration to the perilymph

Question 11

Describe the setup of the three bones of the middle ear going from the tympanic membrane to the oval window:

Answer 11

Malleus to the incus to the stapes

Question 12

What is the name of the fluid that occupies the membranous portion of the inner ear?

Answer 12

Endolymph

Question 13

What is the name of the fluid that occupies the bony labyrinth of the inner ear?

Answer 13

Perilymph

Question 14

What is the name of the reservoir of endolymph for the semi-circular canals?

Answer 14

Utricle

Question 15

What is the name of the endolymph reservoir for the cochlear?

Answer 15

Saccule

Question 16

What is the importance of the second round window?

Answer 16

Allows for vibration of the system

Question 17

What is the name of the endolymphatic sac between the ascending and the descending spiral staicases?

Answer 17

Called the cochlear duct

Question 18

What type of fluid is in the cochlear duct?

Answer 18

endolymph

Question 19

What is the name of the ascending cochlear staircase? What type of fluid is within it?

Answer 19

Scala vestibuli. Perilymph

Question 20

What is the name of the descending pathway of the cochlea and what type of fluid is occupied within it?

Answer 20

Scala tympani

Question 21

How does the cochlea work to detect different frequencies?

Answer 21

The strucutre of the cochlea means different part of the cochlea will vibrate a diffeent frequencies.

Question 22

What is the main function of the semicrular canals?

Answer 22

The main function of the semicircular canals is to detect movement. The loops are suituated in there different planes and the movement of this fluid allows for detection.

Question 23

What is the function of the macula?

Answer 23

The macula are responsible for the static component of movement. Occurs in the utricle and saccule- special organ that detects gravity

Question 24

What is the function of otoliths?

Answer 24

Otholiths are tiny rocks that sit on jelly like memebrane and are deformed in response to movement

Question 25

Where are the cupulla located and what is their function?

Answer 25

Bends in response to waves that are entering the middle ear. They are located within the ampulla themselves