review Flashcards
Intrafusal fibers are where and what innervation?
Intrafusal are in parallel with extrafusal fibers I think
They are mixed nerves
Muscle tone is maintained by
responding to steady state amount of stretch
Intrafusal fibers responds via the gamma motoneuron to modulate
muscle length
alpha motoneuron innervates the _____ and lives_____
lives in the ventral horn and modulates tone via intrafusal fibers
alpha motoneuron innervates the _____ and lives_____
lives in the ventral horn and modulates tone via intrafusal fibers
Stretch reflex has how many synapses?
It’s a monosynaptic reflex
inverse stretch reflex is modulated by
The Golgi tendon organs and has an opposite effect of the stretch reflex (decreases muscle contraction)
has to get to a certain threshold
Flexion reflex initiated by what stimuli?
Noxious Cutaneous
Crossed Extensor reflex can be ___
contralateral
helps maintain balance
Following an upper motor neuron injury what is the course of reflexes expected to be seen?
1-2 weeks after= spinal shock and reflexes are hyporeflexive
then hyperreflexia due to loss of descending inhibition of LMN
Corticospinal lesion will see increased or decreased tonic stretch reflex?
increased tonic stretch reflex
Unconscious proprioception occurs at what level?
spinal cord
Clarke’s nucleus is?
Accessory cuneate for arm
somatotopy is same in primary motor
homonculus
If you are moving from the lonigtudinal fissue to the sylvian fissure within the parietal lobe, what does the somatotopy show
Leg closer to the midline
Then Arm
Then Face
Then pharynx/larynx in that fissure
Just sensory CN?
I (olfactory), II (optic), VIII (vestibulocochlear)
Just motor CN?
III (oculomotor), IV (Trochlear), VI (Abducens), XI (Spinal accessory), XII (Hypoglossal)
Mixed CN?
V, VII, IX, X
Abducting the eye (lateral movement) tests what CN
tests the lateral rectus and the Abducens Nerve (CN IV)
What does your eye lens need to do to see in the distance?
flatten the lens by
Myopia has problem seeing where and a focal point where?
Nearsighted because eye is too long
Focal point would be
need a concave lens
what sort of lens do you need to correct for near sighted-ness
convex
what is power?
1/focal point= diopters
A strong lens has a higher diopter
idk relate this to focal length
Snellen eye chart measures
visual ACUITY
Dark black
dark eosinophilic
in between lighter areas
Dark black= retinal pigment layer
dark eosinophilic= ganglion
in between lighter areas= plexiform layers
What receptors on off-center bipolar cells depolarize bipolars?
AMPA/Kainate
What receptors on on-center bipolar cells depolarize bipolars?
MGluR6 hyperpolarize bipolars
What photoreceptors are helpful at night
Rods: super sensitive to light but poor acuity because many rods synapse on a single bipolar cell
What photoreceptors are helpful for visual acuity w/ light and color vision?
Cones
few cones synapse on a single bipolar cell
what part of the visual field crosses over to the other side via the nasal retinal area?
Temporal visual field
lower half of the eye projects to the inferior region on the upper bank of the sulcus. more central part of the visual field is located
More central is more posterior
Upper half of the eye are represented where on the sulcus?
More central part of visual field is where?
Lower bank of the sulcus
more central is further posterior
