motor pathways Flashcards
Generally, _____ pathways are under direct cortical control and control distal fine motor movements
Lateral pathways
Generally, _____ pathways are under brainstem control and affect posture and movement (extension)
Ventromedial pathways
Name two of the major lateral motor pathways
- corticospinal- does voluntary and precise movment
2. corticobulbar-movement in the face
The corticospinal pathway receives input from where?
Primary motor, and pre and supplemental motor areas
Some input from primary sensory
Track proprioception from periphery to corticospinal pathway
- dorsal column medial lemniscus
- VPL of thalamus
- primary sensory
- areas 5+7 for integration
- area 6 (pre and supplemental motor)
- area 4 Primary motor
- Corticospinal pathway
***cerebellum has accurate body map throughout entire process
T/F M1 neurons fire just before a movement begins and in response to movement
True
Where does M1 primarily project to on the spinal cord?
Lumbar and cervical cord levels. This helps with fine motor control by controlling velocity and direction of movement
T/F M1 receives somatosensory feedback during movement in an ongoing manner and will alter firing in response to input
True
What does area 6 do?
It turns the where actions are (which came from 5 and 7 of parietal lobe) into “how” the actions will be carried out
Where does the supplemental motor cortex receive input from?
basal ganglia
posterior parietal cortex
T/F Cells in the SMA are active during muscle activity
False, one second before
What are the roles of the SMA?
- coordinating voluntary movement
- postural adjustments
- planning and preparation for self initiated movement
Damage to the SMA can result in what conditions?
akinesia
loss of facial expression
difficulty with bilateral tasks
difficulty with initiating movements internally
Where does the Premotor cortex receive input from?
Cerebellum
Basal ganglia
Where does the Premotor cortex primarily connect to?
Reticulospinal pathways to proximal muscles
T/F the premotor cortex is activated before a movement occurs
True. They are most active during the planning of movement
T/F The premotor cortex cells respond to all sensory inputs
False, they filter out all sensory cues unless they relate to movement. They play a huge role in preparation of movement in response to external, sensory cues
Damage to the PMA results in…
apraxia
clumsy slow movement
perseveration, or not responding to external stimuli
impaired ability to learn complex or sequential movement
Difficulty with sensory triggered tasks
T/F the corticobulbar tract synapses with all of the motor cranial nerves
True
T/F all of the corticobulbar projections are bilateral
False, all but
lower face muscles
and
spinal accesory
T/F Lesions of the corticobulbar tract result in paralysis
False, weakness due to bilateral innervation
except for muscles of facial expression and protrusion of tongue which do result in paralysis
T/F The rubrospinal tract does the same thing as the corticospinal tract
True. Don’t worry about it.
____reticulospinal increases muscle tone to facilitate movement and
______ reticulospinal decreases muscle tone to inhibit voluntary movement
Medial– Think trunk
Lateral–Think limbs
Both work together to find the right balance to allow movement of limbs and stop movement of trunk.
Where does the middle cerebral artery supply?
putamen, caudate, and anterior limb of internal capsule
Where does the basilar artery supply?
pons, part of cerebellum
Where does the anterior cerebral artery supply?
medial aspects of the frontal, and parietal lobes, affects primary sensory, and motor regions
Where does the posterior cerebral artery supply?
midbrain, thalamus, subthalamic nucleus
What are the two types of strokes?
Hemmorhagic
Ischemic
Ischemic strokes result from which two things?
Embolic: occlusion of vessels resulting from loose object
Thrombic: Local reduction in blood supply, gradual occlusion
What is the impact of middle crebral artery problems?
Contralateral hemiplegia with greater involvement of the arm, face, tongue, sensory deficits, possibly aphasia if left hemisphere is involved
Anosognosia, unilateral neglect, impaired vertical pereption, visual spatial deficits
What impact would a anterior cerebral artery issue have?
apraxia, contralateral LE weakness, intellectual changes
What is ideomotor vs ideational apraxia?
Ideomotor-Knowing what is needed to do, but unable to do it
Ideation-can’t develop a plan
What impact does a posterior cerebral artery issue have?
homonymous hemianopsia
visual agnosia
memory impairments
What are lacunar strokes?
Occlusion of a small branch of a larger blood vessel.
Tend to be subcortical.
Ex. Internal capsule or thalamus
May affect motor, sensory, or combination
