Motor Systems - LectureCapture Flashcards
Path of the corticospinal and corticonuclear projections
Descend through internal capsule -> cerebral peduncle -> basilar pons -> pyramids -> forms A/L corticospinal systems
What is the primary motor cortex?
Pre central gyrus
Where is the supplementary motor cortex located?
Above the pre/post central gyri
Where is the cortical micturition center located?
On the supplementary motor area, medial superior frontal gyrus for voluntary motor control in pre central gyrus
All LMNs project to
Muscles
All UMNs project to
LMNs
Cranial nerve nuclei are ______ (what type of motor neurons)
UMNs
REVIEW BODY MAP
REVIEW BODY MAP
Lateral cortex is supplied by
MCA
Medial cortex is supplied by
ACA
Face is located where on the internal capsule?
Genu
Posterior limb of internal capsule contains what structures
Arm
Torso
Leg
Somatosensory projections and motor projections use what part of the internal capsule?
Posterior limb
What parts of the brain are active when doing finger flexion or tap finger on a surface?
ONLY primary motor and somatosensory
What parts of the brain are active when doing a finger movement sequence?
Primary motor, somatosensory, and supplementary motor area
What parts of the brain are active when doing a mental rehearsal of a finger tapping sequence?
Supplementary ONLY
Apraxia
Inability to perform a complex movement or sequence of movements (especially learned)
Premotor cortex gets input from
Proprioception, visual system, and thalamic motor nuclei
The premotor cortex guides
The primary motor cortex
If you have premotor damage WITHOUT primary motor damage, what deficits
NO WEAKNESS, you get apraxia (weakness can mask apraxia in some instances)
Input from prefrontal cortex is probably related to what kinds of movements?
Learned (buttoning a shirt)
Supplementary cortex projects to
UMN in primary motor cortex
If you have supplementary cortex damage WITHOUT primary motor damage, what deficits
Apraxia, not weakness
Frontal eye fields function
UMN for voluntary eye movements
Do you have the vestibulocular reflex with FEF damage?
NO - VO still intact
FEF corticonuclear projections are ______ to oculomotor and trochlear
Bilateral
FEF corticonuclear projections are ______ to abducens
Contralateral
FEF drives lateral conjugate gaze towards which side?
Opposite side
Left FEF controls ______ gaze
Rightward
Right FEF controls ______ gaze
Leftwards
Unilateral FEF damage causes
Deviation towards lesion
A left FEF lesion would cause what kind of deviation?
Leftward deviation
This makes sense because the normal function of FEF is rightward gaze, so if damaged, you get a leftward deviation and inability to voluntarily look right
With FEF - if the abducens is intact, you get what kinds of movement?
Reflex, not voluntary
Function of the cortical micturition center
Supresses voiding through projections from the superior frontal gyrus -> pontine micturition center
Frontal type incontinence occurs when what is damaged?
Cortical micturition center
If only one is damaged, deficits are variable
Symptoms of frontal type incontinence
When bladder is full, patent is unable to stop reflex voiding
If only this part of the frontal lobe is damaged, the patient is likely distressed (if more frontal damage, there is less distress)
Sympathetic effect on voiding
Inhibits detrusor, activates sphincter (for urine storage)
Parasympathetic effect on voiding
Activates detrusor, inhibits internal sphincter (may partially compensate for frontal type incontinence)
If primary motor is intact, but premotor is damaged
Aprexia
If primary motor is intact, but FEF is damaged
gaze deviation deficit
If primary motor is intact, but Broca’s is damaged
Language output deficit
Pericallosal branch of the ACA supplies
Cingulate gyrus
Callosmarginal branch of the ACA supplies
Superior frontal gyrus
Occlusion of callosomarginal branch of the ACA results in
Leg portion of PMC, entire supplementary, and cortical micturition center
