Motor Systems and Cerebellum Flashcards
The nerve fiber of the muscle sensor during static and dynamic muscle changes
Group Ia and II afferents (in parallel)
The muscle spindle plays a role in dynamic changes
The nerve fiber of the muscle sensor that is activated when the muscle is tensed
Group Ib afferents in series
The golgi tendon plays a role in muscle tension.
The muscle sensor for vibration is the pacinian corpuscle. It has group ___ nerve fiber.
Group II
Remember: Vibratwo!
Noxius stimuli is detected by group III and IV nerve fibers. It uses ___ muscle sensor.
Free Nerve Endings
This motoneuron maintains the group 1a afferent activity during muscle contraction
Gamma: Intrausal
Alpha: Extrafusal
The golgi-tendon reflex has ____ number of synapses that is triggered when the muscle contracts resulting to antagonistic muscle relaxation
di-synaptic.
Remember, Golgi-Tendon, Di synaptic, stimulated by contractions, resulting to relaxation
Nuclear chain fibers are arrange in rows. This detects ____ changes
Static changes
Nuclear bag detects dynamic changes
Transection at the spinal cord level leads to ___, ____, and _____
- Paraplegia
- Loss of conscious sensation
- Spinal shock
Transection above the lateral vestibular nucleus or pontine reticular formation and midbrain leads to _____ rigidity
decerebrate
Lesions above the red nucleus results to decorticate posturing but intact tonic neck reflexes
These are pathways that originate in the brainstem structures
extrapyramidal tracts
Pyramidal tracts passes through the medullary pyramids
[muscle sensors]
The group Ia and II afferents nerve fiber supplying a muscle spindle responds to changes in muscle ___ (length/tension)
length
[muscle sensors]
the group Ib afferents responds to changes in muscle ___ (length/tension)
tension
[muscle sensors]
The nerve fibers responsible for static and dynamic changes in muscle length are arranged in ___ (parallel/series) with respect to the extrafusal fibers
parallel
[muscle sensors]
The nerve fibers responsible for changes in muscle tension are arranged in ___ (parallel/series) with respect to the extrafusal fibers
series
muscle sensor for changes in length
muscle spindle
muscle sensor for changes in tension
golgi tendon organs
muscle spindle fiber are arranged in ___ (parallel/series) with respect to extrafusal fibers
parallel
golgi tendon organs are arranged in ___ (parallel/series) with respect to extrafusal fibers
series
[muscle sensors]
muscle sensor for position sense
muscle spindle and golgi tendon
between muscle spindles and golgi tendon organs, which are intrafusal fibers?
muscle spindle
[motor neuron]
___ is the motorneuron of extrafusal fibers
alpha
AEGIs
[motor neuron]
___ is the motorneuron of intrafusal fibers
gamma
AEGIs
The motorneuron that causes appropriate muscle contraction and shortening
alpha
the motor neuron that is co-activated during muscle contraction
gamma
[muscle reflexes]
Stimulus: muscle is stretched
Response: muscle contraction
Stretch reflex
[muscle reflexes]
Stimulus: muscle contracts
Response: muscle relaxation
golgi-tendon reflex
inverse stretch reflex
[muscle reflexes]
Stimulus: pain
Response: ipsilateral flexion, contralateral flexion
Flexor-Withdawal reflex
[muscle reflexes]
monosynaptic
type Ia nerve fiber
stretch reflex
[muscle reflexes]
disynaptic
Type Ib nerve fiber
inverse stretch reflex (golgi tendon reflex)
[muscle reflexes]
polysynaptic
Type II, III, IV
flexor-withdrawal reflex
hint: type III and IV = type C = unmyelinated = pain
voluntary motor movements originate in the ____ areas
cerebral cortical association areas
[voluntary motor movement]
this area of the brain coordinates the planning ang execution of a voluntary muscle motor movement
premotor and motor cortex
[voluntary motor movement]
pyramidal tracts that are essential for voluntary movements
corticospinal tract
corticobulbar tract
[voluntary motor movement]
area of the brain (gyrus) that plays a role in voluntary motor movements
precentral
[voluntary motor movement]
all pyramidal tracts pass pass through this part of the brain
medullary pyramids
[voluntary motor movement]
the brainstem is made up of
midbrain, pons, medulla oblongata
[extrapyramidal tract: cite the distribution]
rubrospoinal tract
red nucleus to interneurons
[extrapyramidal tract: cite the distribution]
pontine reticulospinal tract
pons to ventromedial SC
[extrapyramidal tract: cite the distribution]
medullary reticulospinal tract
medullary reticular formation to spinal cord interneurons in the gray area
[extrapyramidal tract: cite the distribution]
lateral vestibulospinal tract
from Deiters nucleus to ipsilateral motorneurons and interneurons
[extrapyramidal tract: cite the distribution]
tectospinal tract
from superior colliculus to cervical spinal cord
[extrapyramidal tract]
stimulate: flexors
Inhibits: extensors
rubrospinal tract
[extrapyramidal tract]
stimulate: flexors, extensors (main)
Inhibits: —–
pontine reticulospinal tract
[extrapyramidal tract]
stimulate: ——-
Inhibits: flexors, extensors (main)
medullary reticulospinal tract
[extrapyramidal tract]
stimulate: extensors
Inhibits: flexors
lateral vestibulospinal tract
[extrapyramidal tract]
controls neck muscles
tectospinal tract
[transection at the SC]
loss of voluntary movements, the transection is ___ (above/below) the lesion
below the lesion
[transection at the SC]
in spinal shock, the reflexes are absent ___ (immediately, 11 mins after, 10 mins) after transection
immediately
[transection at the SC]
HR and BP decreases.
location of SC transection?
C7
[transection at the SC]
breathing stops! :(
location of SC transection?
C3
[transection at the SC]
transection of the SC at this cervical level can easily result to death
C1
[transection above the SC]
lesions above the lateral vestibular nucleus results in ___ (decerebrate/decorticate) rigidity
decerebrate
because the lateral vestibulospinal tract stimulates extensor, damage here leads to unopposed extensor
[transection above the SC]
lesions below the pontine reticular formation and midbrain results in ___ (decerebrate/decorticate rigidity)
decerebrate
because the pontine reticulospinal tract mainly stimulates extensor, there will be unopposed extensor
[transection above the SC]
lesions above the red nucleus leads to ____ (decerebrate/decorticate) posture
decorticate
rubrospinal tract (red nucleus) mainly stimulates flexion. This there will be unopposed flexion
[nuclear bag/chain]
detect dynamic changes
group Ia sensory fiber
nuclear bag
[nuclear bag/chain]
detect static changes
group II sensory fiber
nuclear chain
[type of gamma motor fiber]
ends characterized as TRAIL ending (efferent) at the nuclear chain fiber
static gamma motor fiber
[type of gamma motor fiber]
ends characterized as PLATE ending (efferent) at the nuclear bag fiber
dynamic gamma motor fiber
[type of sensory fiber]
primary ending, both afferent at the nuclear bag and chain fiber
group Ia afferent
[type of sensory fiber]
secondary ending, the afferent ending at the nuclear chain fiber
group II afferent
[stretch reflex]
patellar knee jerk stimulates what type of afferent nerve fiber
Ia
[stretch reflex]
knee jerk reflex results in contraction of what muscle
quadriceps muscle
transection at the level of spinal cord,
the reflexes can/cannot recover after several hours to a few weeks
can
transection at the level of spinal cord,
the loss of conscious sensation will be ___ (above/below) leve of lesion
below
[cerebellum]
control balance and eye movement
vestibulocerebellum
[cerebellum]
for planning and initiation of movement
pontocerebellum
[cerebellum]
controls the rate, force, range, direction of movements
spinocerebellum
[cerebellum: clinical conditions]
loss of muscle coordination, delay initiation, poor execution of movement sequence
ataxia
[cerebellum: clinical conditions]
failure to perform rapid alternating movements
dysdiadochokinesia
[cerebellum: clinical conditions]
low frequency tremor bu increases as an extremity approaches the endpoint of deliberate and visually guided movement
intention tremor
[cerebellum: clinical conditions]
failure of antagonistic muscle to contract after removal of resistance to limb movement
absent rebound phenomenon
[layers of the cerebellar cortex]
___ layer has outputs that are always inhibitory, using GABA
purkinje cell layer
[layers of the cerebellar cortex]
___ layer
only output of the cerebellar cortex; modulates rate, range, and direction of movement
purkinje cell layer
[Neural connection in the cerebellum]
___ cell releases glutamate leading to excitation of the basket and stellate cells
granule cells
(Excite) GR –> BC,NC
[Neural connection in the cerebellum]
___ releases GABA which inhibits purkinje cells
Basket cells
(Inhibit) BC –> PC –> NC
[Neural connection in the cerebellum]
____ cell releases glutamate
granule cells
[Neural connection in the cerebellum]
____ cell releases GABA
basket cells, purkinje cells
[Neural connection in the cerebellum]
___ cell releases GABA which inhibits cerebellar nuclei
purkinje cells
[Neural connection in the cerebellum]
____ exerts a strong excitatory effect on purkinje cells
climbing and mossy fiber inputs
[Neural connection in the cerebellum]
this cell is excited by mossy fiber collaterals
golgi cells
