Neurophysiology 8: Auditory (Lecture 82)

Question 1

Hearing is a response to what?

Answer 1

Vibrating air molecules

Question 2

What is the definition of equilibrium?

Answer 2

The sense of motion, body orientation, and balance

Question 3

Where are hearing and equilibrium both transduced?

Answer 3

Inner ear -> vestibulocochlear nerve (CN VIII)

Question 4

What are the three parts of the inner ear?

Answer 4

Bony labyrinth
Membranous labyrinth
Cochlea

Question 5

The bony labyrinth is a passageway in ______ _____ ______.

Answer 5

Petrous temporal bone

Question 6

Membranous labyrinth is connective tissue tubes within ____ ______

Answer 6

Bony labyrinth

Question 7

What is the membranous labyrinth filled with?
What is the membranous labyrinth floating in?

Answer 7

Filled with endolymph: similar to intracellular fluid, high in K+
Floating in perilymph: similar to cerebrospinal fluid

Question 8

What are the three ducts of the cochlea?

Answer 8

1. Scala vestibuli
2. Scala tympani
3. Scala media (cochlear duct)

Question 9

What is the Scala vestibuli in the cochlea?

What is it filled with?

Begins at _____ _______ and spirals to _____

Answer 9

Dorsal chamber

Perilymph

Begins at oval window and spirals to apex

Question 10

What is the Scala tympani in the cochlea?

What is it filled with?

Beings at _____ and ends at ____ _______.

Answer 10

Ventral chamber

Filled with perilymph

Begins at apex and ends at round window (Secondary tympanic membrane)

Question 11

What is the Scala media (cochlear duct) in the cochlea?

What is it filled with?

Answer 11

Triangular middle chamber

Filled with endolymph (K+ rich)

Question 12

Where are the stereocilica of hair cells embedded?

Answer 12

Tectorial membrane

Question 13

What do hair cells release from their base? They’ are capable of exciting which cranial nerve?

Answer 13

Release neurotransmitter from their base

Exciting the cochlear branch of CN VIII

Question 14

The taller the wave = The _______ the sound

Answer 14

Louder

Question 15

What is conductive deadness?

Answer 15

Conditions interfere with transmission of vibrations to inner ear

(Damaged tympanic membrane, Ottis media, tumors polyps, middle ear fluid)

Question 16

What is sensorineural (nerve) deafness?

Answer 16

Death of hair cells, CN VIII, or any CNS system elements concerned with hearing

(Genetic, geriatric, acquired)

Question 17

What contains the first order neuron for the auditory pathway?

Answer 17

Cochlear n

Question 18

What is the cochlear nuclei in?

Answer 18

Medulla

Question 19

Where does the auditory pathway end up?

Answer 19

Contralateral auditory cortex (temporal lobe)

Question 20

What is acoustic startle reflex?

What is pathway for this reflex

Answer 20

Reflex turning of head and neck

Caudal colliculus -> rostrato colliculus ->tectospinal tract -> stimulate neck muscle ispilatereal contact reaction

Question 21

How does stapedius reflex work

Answer 21

Stapedius muscle contracts
Pulls auditory ossicles
Decreased piston effect
Dampen vibrations transmitted to cochlea

Question 22

What the receptors for olfaction?

Answer 22

Chemoreceptors

Question 23

Olfaction and gustaton transduce _____ ______ into _____ _______

Answer 23

Chemical signals into electrical signals

Question 24

What is the primary afferent neuron itself in the olfactory receptor?

Answer 24

Olfactory receptor cells itself

Question 25

Why is gustatory receptor a specialized epithelial cell?

Answer 25

Transducers chemical signals and then sends electrical signals to primary afferent neuron

Question 26

Which was does air go into olfactory areas

Answer 26

Unidirectional laminar flow

Question 27

What is the right nostril used for?

Answer 27

Novel or noxious smells

Question 28

What is the left nostril used for?

Answer 28

Familiar cells

Question 29

What do olfactory receptors line?

Answer 29

Olfactory epithelium on ethmoturbinates

Question 30

Can most neurons undergo mitosis and replace themselves

Answer 30

No

Question 31

What is special abouit basal cells in olfacotory epithelium?

Answer 31

They divide and replace themselves to replace olfactory neurons

Question 32

Olfactory Transduction?

Answer 32

All you have to know is: G-protein coupled receptor Action potential created in primary afferent neuron

Question 33

What is the olfactory path ?

Answer 33

Cribiform plate to olfactory bulb (1st order neuron) -> mitral cell (2nd order neuron)

Question 34

What is the olfactory Cortex?

Answer 34

Piriform lobe

Question 35

(TRUE/FALSE) In olfactory pathway transmission through thalamus is required

Answer 35

NOT REQUIRED

Question 36

Where are taste buds located in?

Answer 36

Tongue, palate , pharynx, larynx

Question 37

How do taste receptor cells work?

Answer 37

Have microfilm that contain the taste chemoreceptors

Question 38

What is the taste transduction for bitter, sweet, or savory?

Answer 38

G-protein coupled receptor Signaling cascaded eventually opens transient receptor potential Receptor cell is depolarized

Question 39

What is the taste transduction for sour or salty?

Answer 39

Chemicals bind and directly open inotrophic epithelial sodium channels to allow H or Na to enter Receptor cell is depolaraized

Question 40

The primary afferent axons of first order neurons are located in which cranial neverves?

Answer 40

IX, VII and X