Central Control of Movement Flashcards
Map out how information flows through the brain (PNS->CNS->PNS)
Order the components in the correct order of flow
multimodal association corticles
premotor cortex
primary sensory cortex
primary motor cortex
primary sensory cortex -> multimodal accosication corticles -> premotor cortex -> primary motor cortex
what are 3 other brain circuits that send information to the cortex besides afferent and efferent fibers?
- basal nuclei and cerebellum
- limbic system
- reticular activating network
what are the 4 lobes of the cerebral cortex?
parietal lobe
occipital lobe
temporal lobe
frontal lobe
which lobes are sensory corticles and motor cortex?
sensory - parietal, occipital, temporal
motor - frontal
which lobe processes touch?
parietal
which lobe processes visual?
occipital
which lobe processes auditory and memory?
temporal
which lobe processes motor, decision making, and mood?
frontal lobe
what are the 3 regions of the motor cortex?
premotor
supplementary motor
primary motor
what are neurons in the pre and supplementary motor areas linked to?
primary motor cortex
what is motor homunculus?
map of body on cortex
electrical stimulation -> motor response on specific body part
what connects the cortex to the target muscles?
UMN and LMN
where do UMN start and how do they reach LMN?
start - motor cortex
reach LMN via corticopsinal or corticobulbar tracts
where do corticobulbar pathways terminate?
brainstem
where do corticospinal pathways terminate?
spinal cord
List wether each cranial nerve is sensory, motor, or both
which cranial nerves are NOT LMNs?
I - olfactory
II - optic
VIII - vestibulochlear
the ones with only sensory pathways
which cranial nerves are tested in the pupillary light reflex?
II and III
which CN is afferent and efferent - II & III?
II - afferent (sensory)
III - efferent (motor)
where do the LMNs of the corticobulbar tract run through?
cranial nerves
where do axons of corticospinal tracts run through?
lateral and ventromedial white matter
where does the corticospinal tract descussate?
caudal end of medulla
what is the corticospinal tract also called?
pyramidal tract
where are the cell bodies of LMN located?
spinal cord
what are LMNs that innervate skeletal muscle?
a-motorneurons
what is sometimes referred to as the final common pathway?
LMNs
what do LMN for the lateral part of the ventral horn innervate?
muscles of distal limbs
what do LMN from medial part of ventral horn innervate?
axial muscles and proximal limbs
what does the red and green LMN innervate?
red- axial muscles and proximal limbs
green - distal limbs
what is the extrapyramidal system?
neurons located in nuclei of the brainstem
what are the neurons in the nuclei brain stem?
red nucleus, reticular formation, vestibular nucleus, tectum
what does the red nucleus, reticular formation, vestibular nucleus, and tectum make up tracts?
tectospinal
reticulospinal
rubrospinal
vestibulospinal
what tracts are part of the extrapyradmidal system?
tectospinal, reticulospinal, rubrospinal, vestibulospinal
what type of pathology is damage to the extrapyramidal system associated with?
hypertonic and hypotonic
what is decerebrate rigidity?
condition of increased muscle tone and stretch reflexes, particularly extensor muscles
->extensor hypertonia
what is opisothotonus?
spasm of muscles causing backward arching of head and neck
what tract is associated with red nucelus, reticular formation, vestibular nucleus, tectum?
red nucleus - rubrospinal
reticular formation - reticulospinal
vestibular nucleus - vestibulospinal
tectum - tectospinal
which tract is associated with distal musculature?
rubrospinal
which tract is associated with axial and proximal musculature?
reticulospinal
vestibulospinal
tectospinal
where does the red nucleus receives input from?
motor cortex and the cerebellum
what does rubrospinal tract excite?
LMNS that control flexor muscles in neck and proximal limbs
what does rubrospinal tract inhibit?
extensor muscles in limbs
what can damage to rubrospinal tract cause?
extensor hypertonia
which reticulospinal tract excites alpha and gamma neurons to extensor muscles?
pontine
which reticulospinal tract inhibits the pontine tract? what does that results in?
medullar
inhibit extensor muscles
what does the two tracts of the reticulospinal tract allow for?
balance in influences on extensor and flexor muscles
a-y coactivation
when will postural control with the reticulospinal tract be decreased?
lesions
what can injury to the pontine tract result in?
hypotonia - flaccidity
what can injury to the medullar tract result in?
hypertonia - spasticity
what does the vestibulospinal tract control?
body position and disturbances in balancewhst
what can damage to the vestibulospinal tract cause?
extensor hypotonia
what does the vestibular nucleus recieve inputs from?
vestibular apparatus of inner ear and cerebellum
what does the superior (rostral) colliculus receive inputs from and what about?
visual, auditory, an somatosensory inputs about environmental stimuli
what can damage to the tectospinal tract cause?
disruption in the ability to orient head towards and fix gaze on an object
which tract transfer information for voluntary motor action? UMN or extrapyramidal?
UMN/pyramidal
which tract exerts control on LMN to increase fine control? UMN or extrapyramidal?
extrapyramidal
which tract fine tunes spinal reflexes? UMN or extrapyramidal?
extrapyramidal
which tract interacts with basal nuclei and cerebellum to fine tune motor control? UMN or extrapyramidal?
extrapyramidal
what can damage to UMNs cause?
inability to move
inappropriate movements (hyperreflexia), increased muscle tone, possibly muscle atrophy
Cerebral palsy is an example of a disease that affects UMN or extrapyramidal?
UMN
what are LMNs innervated by?
UMNs, extrapyramidal neurons, reflex arcs
what do LMNs do?
stimulate muscles
what can damage to LMN cause?
inappropriate or absence of movement (hyporeflexoa, flaccid muscles, paraplegia); muscle atropy and reduced muscle tone
Feline diabetic neuropathy is an example of a disease that affects UMN or LMN?
LMN
axonal endings of DISTAL axons demyelinate and die
what does muscle tone refer to?
resting level of tension in a mucle
what is muscle tone the result of?
resting level of discharge of a-motor neurons
what regulates the a-motor neuron discharge?
muscle spindle afferents
a-y coactivation
what does damage of a-motorneuron (LMN) do to muscle tone?
reduced muscle tone
what does damage to UMN do to muscle tone?
increase muscle tone
what does a UMN lesion do to supraspinal inhibitory and excitatory inputs (extrapyramidal)?
disturbs balance of supraspinal inhibition and excitatory inputs - extrapyramidal ->state of net disinhibition
what is damaged when a dog is opisthotonus?
red nucleus damaged and reticular formation neurons working -> dog in extension
what does decerebrate rigidity result from?
midbrain lesion
above pons, medulla. vestibular nuceli and below red nucelus
where does each extrapyramidal tract go in the spinal cord? (lateral and ventral column)
lateral column - rubrospinal tract
ventral column - reticulospinal tract, tectospinal tract, vestibulospinal tract
what UMN tract synapses on cranial nerves?
corticobulbar
