Exam 3 Week 12 ppt 11 Voluntary Movement Flashcards
Motor Control is
the ability to regulate or direct the mechanisms essential to movement
Motor Planning is
the preliminary organization prior to movement
Programming is
the specifications that allow movement to progress
Motor Cortical Areas have _ main area (and what are they)
3 ~frontal areas ~parietal areas ~limbic areas
What are the _ parts of the frontal area for motor cortical areas?
3 ~primary motor ~supplementary motor ~lateral pre-motor
What is the main part of the parietal area for motor cortical areas?
posterior partial area
What are the _ main parts for the limbic area for motor cortical areas?
2 ~anterior cingulate areas ~posterior cingulate areas
Where is the primary motor cortex located?
precentral gyrus; Brodmann’s area 4
Where is the supplementary motor cortex located?
most superior and medial aspects of superior frontal gyrus; just rostral to the primary motor cortex
Where is the pre-motor cortex located?
along the lateral frontal cortex; just rostral to the primary motor cortex and along most of its length
Somatotopic organization of the primary motor cortex
~homunculus ~LE – dorsomedial ~UE & face– ventro-lateral ~also has a fractured somatotopy
fractured somatotopy
overlapping regions and scattered distributions of motor neurons with innervate specific muscles
example of fractured homunculus in the cortical motor neurons
~Using the intrinsic thumb muscles as an example, CM neurons for the thumb instrinsic muscles are over all 4 regions ~There is overlap with cortical motor neurons innervating the finger muscles in one area but in other areas thumb muscle cortical motor neurons overlap with wrist, orofacial and even trunk cortical motor neurons
Primary motor cortex and it’s role in movement
~some debate as to the role of the Primary motor cortex in movement ~Most agree it is the Lowest level of motor cortical hierarchy – an irony that the “primary” motor cortex is actually the lowest in the hierarchy ~controversy comes with the debate between those who feel that the primary motor cortex Encode specific muscle kinetic features such as the amount of force for specific movement versus those who feel that it specializes in the Kinematic features, that is speed, direction & spatial path. Both may likely be its function.
Supplemental motor cortex somatotopic
~face, UE & LE arranged in a rostral-caudal orientation
Supplemental motor cortex and its role in movement
~Stimulation of this area elicits movements but in complex synergy patterns ~Active up to 120 ms before movements occur; suggesting a site for motor planning ~strengthened by SMA projections to basal nuclei and cerebellum which help in organization of the movement performed by the primary motor cortex
Damage to supplementary motor cortex will cause
~Damage to the Supplementary Motor Cortex produces problem in bimanual tasks, motor memory and motor learning
Premotor cortex and its role in movements
~Rough somatotopic organization that parallels the primary motor cortex ~synergy patterns when stimulated ~some debate whether kinematic features of targeting movements here rather than 1° motor cortex
posterior parietal cortex and its role in movement
~Critical for providing spatial information for goal-directed movement ~provides the knowledge of Spatial relationships of the environment and how these impact the movement as it takes place ~Critical spatial information for goal-directed movement such as the relative Orientation of the body toward the goal directed objects and determination of the Relative shapes & sizes & orientation of objects within the environment
Limbic cortex- somatotopic
face to feet in rostral-caudal
Limbic cortex- contributes to/ projects to
~contributes along with the parietal lobe to about third of pyramidal tract neurons ~Cingulospinal projections terminate in the intermediate gray, influencing LMNs via interneurons ~anterior cingulate cortex Receives widespread input from amygdala and non-motor areas of cingulate gyrus
anterior cingulate gyrus (function)
provides motivational and reward (goal of performance) information
Cortical connections related to motor function- inputs
(info & list 5 locations)
- Input to the primary motor cortex comes from the 1° somatosensory areas analogous to the regions of 1° motor cortex (particularly hand region
- Input into the 1° motor cortex from:
- pre-motor cortex
- SMA
- CMA (Cingulate motor area)
- DLPFC (Dorsolateral prefrontal cortex)
- Posterior parietal input
DLPFC (Dorsolateral prefrontal cortex) input details
~input into 1° motor cortex and into SMA & CMA ~input provides for Short term memory for action related sensory information, for the Preparatory motor set ~allow for the Inhibition of motor response to distracting stimuli
What are two types of sub-cortical connections?
~basal nuclei loop ~Cerebellar loop
Basal Nuclei Loop
~Supplementary motor cortex projects to the to the striatum ~direct and indirect pathways within the basal nuclei ~incorporation of the substantia nigra with then the normal outputs of GPi/SNr to VL/VA thalamus then onto 1° motor cortex
Cerebellar Loop
~1° motor cortex & pre-motor cortex to pontine & inferior olivary nuclei ~pontocerebellar and olivocerebellar fibers have Input to cerebellar deep nuclei & cortex ~Deep nuclei then have output to the VL thalamus & back to 1° motor cortex
PAS (perceptual action system)
~purposeful movement does not occur in isolation from the sensory perceptual experience of the environment but requires input from the environment to correctly execute motor action
Haptic sensing
~the generation of sensory input from deliberate motor action EX: Exploration of an object by the hand and the Integration of cutaneous and propioceptive information into motor commands ~require working memory which is provided by action of the Dorsolateral prefrontal cortex & posterior parietal cortex
Saccades
~Ballistic voluntary conjugate eye movements used to capture a visual image onto the fovea of the retina ~Used in reading and visual scanning ~Motor programs for saccades reside in reticular formation of midbrain & pons – central pattern generator for conjugate eye movement.
Superior Colliculus control movement by
~Coordinates movements of the eyes via tectobulbar projections (to reticular formation central pattern generator neurons) ~Coordinates movements of head via the tectospinal tract (to cervical spinal cord)
frontal eye field is located
middle frontal gyrus rostral to premotor cortex
frontal eye field function
generates contralateral horizontal conjugate eye movement
frontal eye field projections
~superior colliculus ~reticular formation
supplementary eye field projects to
~brainstem ~frontal eye field
parietal eye field projects to
~brainstem ~frontal eye field
function of Wernicke’s area
hearing and interpretation of language command
function of posterior parietal cortex
placing command within the movement space = spatial env and coordination of eye movement to that site of placement
What are four inputs to the primary motor cortex?
- 1° somatosensory input to analogous regions of 1° motor cortex (particularly hand region) (a) 2. SMA, CMA prefrontal input into 1° motor cortex (a) 3. Dorsolateral prefrontal cortex (DLPFC) input into 1° motor cortex (b) 4. Posterior parietal input to 1° motor cortex (b)
What is the function of saccades?
~Ballistic voluntary conjugate eye movements used to capture a visual image onto the fovea of the retina
what tasks are saccades used for? (2)
~Used in reading and visual scanning
where do motor programs for saccades reside? What can these locations be referred to as?
~Motor programs for saccades reside in reticular formation of midbrain & pons – central pattern generator for conjugate eye movement.
describe the somatotopic organization of the premotor cortex
~Rough somatotopic organization that parallels the primary motor cortex
what can happen when premotor cortex is stimulated?
synergy patterns
what is a debate about the premotor cortex?
~some debate whether kinematic features of targeting movements here rather than 1° motor cortex
