Exam 2 Study Questions Flashcards
Exam 2
If you are missing a S, M, or L, opsin, what might be the symptoms?
Colorblindness
Steps of synaptic transmission (5)
- Action potential arrives at terminal
- VGCa2+ channels open and Ca2+ rushes into cell
- Ca2+ warps the synaptic vesicles, releasing NTs
- NTs diffuse across the synapse
- NT binds to receptor of pstn
Light transduction in light (6-7)
- Light hits opsin
- Opsin activates it’s G-protein, which diffuses across the cell
- The G-protein activates the PDE
- PDE catalyzes cGMP and turns it into GMP
- Lack of cGMP CLOSES the ion channel
- Membrane becomes more negative
- NT Glu is not released
Do photoreceptors release NT Glu in the dark or in the light?
Dark
Is Glutamate excitatory or inhibitory in ON BPC
Inhibited
Off in dark
- Glu is released
- Excitatory Glu excites the cell
- Releases NT to P or M ganglion
- Ganglion sends AP
On in light
- No inhibitory glu is released
- Cell is depolarized
- Releases NT to P or M ganglion
- Ganglion sends AP
Rods have high/low spatial resolution, high/low sensitivity to light, and are responsible for _________ Vision
Low; High; Black and white
Cutting the optic chiasm will affect the
Left nasal and right nasal; Outer portions of L and R visual field
What does the basilar membrane do?
Moves up the Organ of Corti, which bends the hair cells.
Where is the endolymph? High/Low K+ ECF conc?
Top around the stereocilia; High (K+ flows in)
Where is the perilymph? High/Low K+ ECF conc.
Below around the Cell body; Low (K+ flows out)
What do hair cells release onto the spiral ganglion cell?
Glutamate
Steps of audition in the hair cell
- Basilar membrane moves up
- K+ and Ca2+ flows into the hair cells
- Cell is depolarized
- The VGCa2+ open allowing for Ca2+ to flow inside
- The cell body releases glutamate to post spiral ganglion
- Ganglion sends AP
How do we code for frequency of sound?
Tonotopy (Location based excitation)
How do we code for intensity of sound?
Amount of NTs released
Increased amplitude =
Increased intensity/larger waves
What is the first brain area with input from both ears?
The superior olivary complex
What is the pathway of sound?
- Same side ventral cochlear nucleus
- Bilateral superior olivary complex
- Lateral lemniscus
- Inferior colliculus
- Medial geniculate body
- Superior temporal gyrus
A humans perception of a pitch corresponds to the _____________ of a sound wave; perception of loudness corresponds to the _________ of a sound wave
frequency; amplitude
What is the main function of the ossicles?
Transfer vibrations from the tympanic membrane to the oval window
What is the main function of the hair cells?
Directly convert sound vibrations into neural impulses
In order to increase the decibel measurement of a sound, one would have to alter its wave
amplitude
What quality gives rise to tonotopy along the cochlea?
The changing width and stiffness of the basilar membrane
Which auditory property most depends upon the utilization of bilateral auditory information?
Sound localization
The apex is _______ and ________. It is meant for the transmission of __________
Thick and floppy; Lower frequency
The base is __________ and _______________. It is meant for the transmission of _______
Thin and stiff; High frequency
