Ear II

Question 1

What structure detects equilibrium and balace?

Answer 1

The vestibular apparatus

Question 2

What composes the vestibular apparatus?

Answer 2

Saccule
Utricule
Semicircular canals

Question 3

What is static equilibrium?

Answer 3

Maintenance of body position (mainly the head)

Relative to the force of gravity, but also to linear acceleration

Question 4

What is dynamic equilibrium?

Answer 4

Maintenance of body position (mainly the head)

In response to dynamic movements: rotation, acceleration, deceleration

Question 5

What does the saccule look like?

Answer 5

Has a globular shape?

Question 6

What does the utricule look like?

Answer 6

Has a larger, oblong shape

Question 7

What is a macula?

Answer 7

A spot where receptor hair cells are 2-3mm long

Question 8

Where are there macula?

Answer 8

There is one in both the saccule and the utricule

Question 9

What is the otolithic membrane?

Answer 9

A gelatinous mass lying on top of the hair cells

Question 10

What are the two kinds of hairs in the otolithic membrane?

Answer 10

Many stereocilia and 1 kinocilium

Question 11

What is an otolith?

Answer 11

Particles of calcium carbonate embedded in the top of the membrane

Question 12

What do otoliths do?

Answer 12

Respond to gravity (the tilting of the head)

Question 13

Which structures assist with static equilibrium?

Answer 13

The saccule and utricule

Question 14

What structures assist with dynamic equilibrium?

Answer 14

The three semicircular canals

Question 15

What are the semicircular canals?

Answer 15

Three ducts at right angles to each other

Question 16

What kinds of movements do the canals “read”?

Answer 16

1- Reads the “yes” movement (pitch)
2- Reads the “no” movement (yaw)
3- Reads Tilting of the head (roll)

Question 17

Each canal opens up into the utricle and has a dilated area called the ______.

Answer 17

ampulla

Question 18

Within the ampulla is a mound of hair cells and support cells and this area is called the _______ ________.

Answer 18

crista ampullaris

Question 19

What is the cupula?

Answer 19

A gelatinous mass lying on top of these hairs at the crista ampullaris

Question 20

What kinds of hairs are in the crista ampullaris?

Answer 20

Many stereocilia and 1 kinocilium

Question 21

How is a nerve response triggered from the cupula?

Answer 21

As endolymph flows around in the canal, the bends the cupola, moving the cilia, and triggering a nerve response

Question 22

Are hair cells nerves?

Answer 22

Hair cells are mechanoreceptors, not neurons. Therefore, you need a nerve fiber.

Question 23

Which cranial nerve transmits information from the ear?

Answer 23

VIII- vestibulocochlear

Question 24

Where do the macula and ampulla synapse?

Answer 24

synapse at their bases with sensory fibers of the vestibular nerve (This is a 1st order neuron)

Question 25

The cochlea is attached to the ________.

Answer 25

saccule

Question 26

What does the cochlea sit in?

Answer 26

Sits in a bony spiral canal that resembles a snail shell

Question 27

The cochlea makes ______turns around the _____.

Answer 27

3 | Modiolus

Question 28

What is the modiolus?

Answer 28

the bony core if the “snail shell”

Question 29

What three channels compose the cochlea?

Answer 29

Scala vestibuli Scala tymapni Scala media

Question 30

Which channels have perilymph in them?

Answer 30

Scala vestibuli and scala tympani

Question 31

What connects the scala vestibuli and scala tympani?

Answer 31

The helicotrema

Question 32

The cochlear duct is also known as the ______ _____.

Answer 32

Scala media

Question 33

The scala media is part of the _________ labyrinth and therefore contains __________.

Answer 33

Membranous labyrinth | Endolymph

Question 34

What is the organ or Corti?

Answer 34

The receptor organ for hearing

Question 35

What type of cells make up the organ of Corti?

Answer 35

Support cells | Hair cells

Question 36

What “sits” on top of the organ of corti, anchoring it to the modiolus?

Answer 36

The tectorial membrane

Question 37

How does pressure move through the cochlea triggering the organ of Corti?

Answer 37

Pressure waves coming from the oval window travel through the scala vestibuli, through the helicotrema, and travel back down through the scala tympani causing the round window to bulge slightly in the inner ear.

Question 38

What two kinds of hair cells are in the organ of Corti?

Answer 38

IHCs- Inner Hair Cells | OHCs- Outer Hair Cells

Question 39

How are IHCs arranged? Are they embedded in a membrane?

Answer 39

Arranges in one row, are NOT embedded in the tectorial membrane

Question 40

What are IHCs responsible for?

Answer 40

All that we hear

Question 41

How are OHCs arranged?

Answer 41

Arranged in three rows across from the IHCs

Question 42

The tips of the OHCs are embedded in the _______ _____.

Answer 42

Tectorial membrane

Question 43

What do the OHCs do?

Answer 43

Adjust the response of the cochlea to different frequencies

Question 44

Where are different frequencies detected in the cochlea?

Answer 44

High frequencies: Basal turn Middle frequencies: Middle turn Low frequencies: Apex

Question 45

What is conduction deafness?

Answer 45

damage to the tympanic membrane or the ossicles

Question 46

What is sensorial deafness?

Answer 46

damage to organ of corti or 1st/2nd/3rd order sensory neurons

Question 47

What are the two different kinds of deafness?

Answer 47

Conduction and sensorial

Question 48

What can a cochlear implant do?

Answer 48

Can help restore hearing to patients with conduction deafness

Question 49

What is the neuron pathway for hearing?

Answer 49

1st order: From hair cell to cochlear nuclei in the medulla 2nd order: Cochlear nuclei to the thalamus 3rd order: Thalamus to primary auditory cortex in the temporal lobe