The Eart

Question 1

What is the pathway for transmission of sound?

Answer 1

1. ossicles (MIS) transmit sounds waves from ear drum to oval window
2. Fluid waves travel through perilymph to round window
3. Fluid waves re transmitted to endolymph-filled cochlear duct and stimulate hair cells

Question 2

What makes the cerumen?

Answer 2

Ceruminous glands in the external acoustic meatus

Question 3

What is the size of the oval window compared to the tympanic membrane?

Answer 3

It’s 1/18th the size

Question 4

What are the effects of Ménière’s disease?

Answer 4

Vertigo, hearing loss, tinnitus

Question 5

What is Ménière’s disease?

Answer 5

Malfunction of endolymphatic sac results in increase of endolymphatic volume (hydrops) and distensiones in the membranous labyrinth and cochlear duct.

Question 6

What are the concentrations of endolymph?

Answer 6

High protein content

Low Na+ content

High K+ content

Question 7

What are the ion concentration of perilymph?

Answer 7

High Na+

Low K+

Question 8

The utricle and saccule make up what organ?

Answer 8

The vestibule

Question 9

The cochlear duct is used for?

Answer 9

Hearing

Question 10

The semicircular canal are used for?

Answer 10

Balance

Question 11

How does the endolymphatic sac regulate endolymph volume?

Answer 11

By maintaining a high protein content, thereby creating an osmotic gradient that draws fluid into the membranous labyrinth.

Question 12

What is tinnitus?

Answer 12

Funny sounds

Question 13

What part of the vestibular system measures linear acceleration?

Answer 13

2 sacs:

1. Utricle with macula: horizontal
2. Saccule with macula: vertical

Question 14

What part of the vestibular system is responsible for angular acceleration?

Answer 14

3 semicircular canals (ampullae with crista ampularis)

Question 15

What part of the auditory system is responsible for sound perception?

Answer 15

Cochlear duct with organ of corti

Question 16

What are otoconi?

Answer 16

Calcium carbonate stones used to find out which way you’re moving

Question 17

What is the true cilia within the membranous labyrinth?

Answer 17

Kinocilium

Question 18

Mechanical deformation toward the kinocilium _____ K+ channels in the sterocilia.

Answer 18

Open

Question 19

Mechanical deformation way from the kinocilium ______ K+ channels in the sterocilia.

Answer 19

Closes

Question 20

When K+ channels open in the kinocilium, what happens?

Answer 20

Ca+ enters the cell, allowing vesicles fusion and release of neurotransmitter.

Note: K+ leaves the cell via K+ channels

Question 21

What do you call the bony labyrinth in the cochlea?

Answer 21

Scala vestibuli

Scala tympani

(Depends on what part you’re on, vestibuli is on top and tympani is on bottom)

Question 22

What do you call the membranous labyrinth in the cochlea?

Answer 22

Scala media/cochlear duct

Question 23

What type are inner and outer hair cells in the cochlea?

Answer 23

Inner: type 1

Outer: type 2

Question 24

What are border cells? (Cochlea)

Answer 24

Supportive cells

Question 25

What are the scala vestibuli and tympani filled with?

Answer 25

Perilymph high in Na+ content

Question 26

What creates endolymph?

Answer 26

Stria vasularis

Question 27

What is Stria Vasularis?

Answer 27

Pseudostratified epithelium

Vascular tissue

K+ homeostasis of endolymph

Question 28

What separates the scala vestibuli from the cochlear duct?

Answer 28

Vestibular (Reissner’s) membrane

Question 29

What kind hair cells are in the hearing apparatus?

Answer 29

Type 1 are connected to the cochlear nerve (inner)

Type 2 are arrange in rows of 3 (outer hair cells)