Unit 3 Final Exam Flashcards
Retinofugal projections are axons that leave the
retina of the eye
What is the main target of retinofugal projections
LGN of thalamus
The right visual fields fall on the temporal hemiretina of the _____ eye and the nasal hemiretina of the ____ eye
left; right
The left visual fields falls on the temporal hemiretina of the _____ eye and the nasal hemiretina of the _____ eye
right; left
Retina to LGN: function
conscious vision, movement, and object recognition
LGN: layers 3-6
color and detail
LGN: layers 1 and 2
patterns and motion
layers 1,4,6
contralateral inputs
Layers 2,3,5
ipsilateral inputs
Right LGN = _____ side of the world
left
Is there binocular vision in LGN
no
Pretectum
pupillary light reflex
Superior colliculus
gaze shifting/eye movements
SCN
circadian rythmn
Pretectum neurons synapse bilaterally onto
Edinger Westphal nucleus (lll)
E-W lll nuclei send upper motor neurons to the _________ outside the eye as part of CN lll
ciliary ganglion
Ciliary ganglion lower motor neurons will tell our eye to
constrict pupil via muscles
Conjugate eye movement
activating opposite muscles of L and R eyes to move towards same point in space
Vergence movement
move the central axis of each eye towards (convergence) or away (divergence)
Is light required to keep the circadian clock
yes
What visual functions only need to detect the presence of light and not the use of rods and cones
pupillary light
circadian rhythms
What type of ganglion cells are used with SCN
photo-sensitive retinal cells
How are intrinsically photo-sensitive RGCs distributed
evenly over the retina
_______: Rapid small conjugate movements that change the point of fixation
Saccades
_______: slow conjugate movements to follow a target
smooth pursuits
_______: eye movements that compensate for head rotation
VOR
_______: slow, dis conjugate eye movments to change the focal distance
Vergence
_______: small, involuntary movements necessary for vision
fill in blindspot–mini eye movements
What 3 things need to happen for the accommodation of the eye
convergence
constriction
contraction or constriction of ciliary muscles and lens
Accommodation of the eye, same circuitry as the pupillary light reflex BUT requires what
cortical feedback
_____: automatically produces slow eye movement in the direction opposite to the head movement
VOR
What does VOR rely on
semicircular canals
Nystagmus
Combination of slow movements and quick saccades
Nystagmus has an auto reflex to keep the image focused in place on the retina due to
direction-selective retinal ganglion cells
e.g. optikinetic nystagmus
looking out the window in a moving car or train without moving the head
e.g. vestibular nystagmus
spinning in circle and quickly stopping
VOR circuit is used to stabilize
vision quickly to keep image sharp
VOR uses what nuclei
oculumotor and abducens
VOR: what will help increase rxn time
direct projection from vestibular nucleus to nucleus lll
VOR: semicircular canals report on angular velocity, but eyes are small and located further away from the center of head than the canals
we use gain:
change in eye angle/change in angle during head turn
PPRF does
saccade generator
provide input to abduces
horizontal gaze correction
What does blindsight occur
in the absence of V1
Deep layers of SC maintain what
auditory map of space through the auditory cortex and inferior colliculi
Others rely on stereopsis and integration of visual and auditory input in a more critical way than humans T/F
T
Do owls have large binocular visual zone
Yes
Are owls able to perceive 3D movement
yes
Barn owl vision: fairly low visual acuity –> must integrate
auditory input as well
Barn owl audition: asymmetrical ear opening
right ear up; left ear down
Barn owl audition: Azimuth
horizontal
Barn owl audition: elevation
vertical
Barn owl audition: ITD
horizontal
Barn owl audition: ITD uses
superior olives
Barn owl audition: ILD
vertically
Barn owl audition: ILD left plug
the owl looked too high
Barn owl audition: ILD right plug
owl looking too low
Visual and auditory integration in barn owls: what happens when earplugs are worn? what if earplugs and blinds are worn?
Earplugs only–barn owls would adapt within a few weeks
Earplugs and blinders–they would not improve because both visual and auditory input is needed
Barn owl: auditory responses immediately after removing prisms show errors in _______ direction from prism shift
opposite
Where is the initial processing in vision done by
done by non photoreceptor cells in the retina
Cochlea just has hair cells, so initial processing and localization don’t by bilateral _____ _____ (superior olive and inferior colliculus) to form a map of auditory space
brainstem nuclei
________ nerve reports on touch to the eye
trigeminal
auto reflex to trigger ________ nerve to blink
facial
Regulation of muscle tone, coordination of skilled voluntary movement
Spinocerebellum
Aids learning of skilled movement; allows them to become more rapid with precise with learning
cerebrocerebellum
Maintenance of balance, control of eye movements
Vestibulocerebellum
Superior cerebellar peduncles: _______ to the cortex
output
Middle cerebellar peduncles: Input from cortex via pons using
pontine nuclei
Inferior cerebellar peduncles: input from
body and inferior olives (some output to vestibular nuclei)
Superior cerebellar peduncle: almost all fibers are efferent from the cerebellum to ______ cortex
Contralateral
Superior cerebellar peduncles: exit cerebellum via deep cerebellar nuclei to ______ thalamus
contralateral
The superior cerebellar peduncle provides important feedback for lateral motor systems via the motor cortex ( ____) and red nucleus (_____)
corticospinal
rubrospinal
Superior cerebellar peduncle: projections from deep cerebellar nuclei (dentate, interpositions and fastigial) to ________ red nucleus and VA/VL thalamus
contralateral
Superior cerebellar peduncles: deep nuclei receive GABAergic ______ inputs from purkinje cells in the cerebellar cortex
inhibitory
Where is middle cerebellar peduncles found
pons
Pontine nuclei look like
grey matter of well-marbled steak
Middle cerebellar peduncles is input from ______ motor cortex via relays in pontine nuclei
contralateral
____ cells: sole source of output from cerebellar cortex to deep cerebellar nuclei
Purkinje cells
Purkinje cells are GABAergic so
inhibitory
Granule cells receive input via
mossy fibers from pontine nuclei
Granule cell axons rise into the molecular layer and become
parallel fibers
Climbing fibers originate from contralateral
inferior olives
Climbing fibers wrap around
Purkinje cells
A single climbing fiber contacts up to 10 P Cells but each P cell…
has only a single climbing fiber input
Activation of P cells results in a strong
depolarization
Baskey cells, Golgi cells, and stellate cells act like _____ interneurons providing _______ input to Purkinje
inhibitory
Climbing and mossy/parallel fibers are all
excitatory
Cerebrocerebellum is for _____ movement
planning
_________ movements that are uncoordinated or inaccurate due to any damage to motor areas
ataxia
_____ decomposition of complex multijoint movements into parts (robotic-like)
dyssynergia
_______ poor control of speed and distance for coordinated movements
dysmetria
Damage to the cerebellum produces deficits on
same side of the body
Lab: cerebellum lesions prevent what
Inferior olive and pons lesions as well as cerebellum lesions prevent learning
Lab: does damage to VA/VL thalamus produce ataxia but not impair adaptation
yes
Cerebellar motor learning of this is specific…
to the body part trained and the type of movement
Information from the intermediate zone next to vermis goes to what
interpositus nucleus
Information from the Vermis goes to what
fastigial nucleus
interpositus nucleus to what path
rubrospinal
fastigial nucleus to what path
reticulospinal
