Neurophysiology 8: Auditory (Lecture 82) Flashcards
Hearing is a response to what?
Vibrating air molecules
What is the definition of equilibrium?
The sense of motion, body orientation, and balance
Where are hearing and equilibrium both transduced?
Inner ear -> vestibulocochlear nerve (CN VIII)
What are the three parts of the inner ear?
Bony labyrinth
Membranous labyrinth
Cochlea
The bony labyrinth is a passageway in ______ _____ ______.
Petrous temporal bone
Membranous labyrinth is connective tissue tubes within ____ ______
Bony labyrinth
What is the membranous labyrinth filled with?
What is the membranous labyrinth floating in?
Filled with endolymph: similar to intracellular fluid, high in K+
Floating in perilymph: similar to cerebrospinal fluid
What are the three ducts of the cochlea?
- Scala vestibuli
- Scala tympani
- Scala media (cochlear duct)
What is the Scala vestibuli in the cochlea?
What is it filled with?
Begins at _____ _______ and spirals to _____
Dorsal chamber
Perilymph
Begins at oval window and spirals to apex
What is the Scala tympani in the cochlea?
What is it filled with?
Beings at _____ and ends at ____ _______.
Ventral chamber
Filled with perilymph
Begins at apex and ends at round window (Secondary tympanic membrane)
What is the Scala media (cochlear duct) in the cochlea?
What is it filled with?
Triangular middle chamber
Filled with endolymph (K+ rich)
Where are the stereocilica of hair cells embedded?
Tectorial membrane
What do hair cells release from their base? They’ are capable of exciting which cranial nerve?
Release neurotransmitter from their base
Exciting the cochlear branch of CN VIII
The taller the wave = The _______ the sound
Louder
What is conductive deadness?
Conditions interfere with transmission of vibrations to inner ear
(Damaged tympanic membrane, Ottis media, tumors polyps, middle ear fluid)
What is sensorineural (nerve) deafness?
Death of hair cells, CN VIII, or any CNS system elements concerned with hearing
(Genetic, geriatric, acquired)
What contains the first order neuron for the auditory pathway?
Cochlear n
What is the cochlear nuclei in?
Medulla
Where does the auditory pathway end up?
Contralateral auditory cortex (temporal lobe)
What is acoustic startle reflex?
What is pathway for this reflex
Reflex turning of head and neck
Caudal colliculus -> rostrato colliculus ->tectospinal tract -> stimulate neck muscle ispilatereal contact reaction
How does stapedius reflex work
Stapedius muscle contracts
Pulls auditory ossicles
Decreased piston effect
Dampen vibrations transmitted to cochlea
What the receptors for olfaction?
Chemoreceptors
Olfaction and gustaton transduce _____ ______ into _____ _______
Chemical signals into electrical signals
What is the primary afferent neuron itself in the olfactory receptor?
Olfactory receptor cells itself
Why is gustatory receptor a specialized epithelial cell?
Transducers chemical signals and then sends electrical signals to primary afferent neuron
Which was does air go into olfactory areas
Unidirectional laminar flow
What is the right nostril used for?
Novel or noxious smells
What is the left nostril used for?
Familiar cells
What do olfactory receptors line?
Olfactory epithelium on ethmoturbinates
Can most neurons undergo mitosis and replace themselves
No
What is special abouit basal cells in olfacotory epithelium?
They divide and replace themselves to replace olfactory neurons
Olfactory Transduction?
All you have to know is:
G-protein coupled receptor
Action potential created in primary afferent neuron
What is the olfactory path ?
Cribiform plate to olfactory bulb (1st order neuron) -> mitral cell (2nd order neuron)
What is the olfactory Cortex?
Piriform lobe
(TRUE/FALSE) In olfactory pathway transmission through thalamus is required
NOT REQUIRED
Where are taste buds located in?
Tongue, palate , pharynx, larynx
How do taste receptor cells work?
Have microfilm that contain the taste chemoreceptors
What is the taste transduction for bitter, sweet, or savory?
G-protein coupled receptor
Signaling cascaded eventually opens transient receptor potential
Receptor cell is depolarized
What is the taste transduction for sour or salty?
Chemicals bind and directly open inotrophic epithelial sodium channels to allow H or Na to enter
Receptor cell is depolaraized
The primary afferent axons of first order neurons are located in which cranial neverves?
IX, VII and X
