Movement Lecture 4 Flashcards
Output of Posterior Parietal Cortex
Premotor cortex
Cingulate Cortex is involved with?
Expression of an emotional state
Collateral branches of axons cross the midline via
ventral white commissure to reach the opposite ventral horn
Where does Lateral Corticospinal Tract Terminate?
Terminate contralaterally in the dorsal lateral region of the ventral horn
Course of Corticospinal
- Descend through internal capsule
- Cerebral pedencles of the midbrain
- Basilar pons
- Medullary Pyramids
Input to Posterior Parietal Cortex?
Primary Somatosensory Cortex
Visual Association Cortex
Function of Posterior Parietal Cortex
Sensory contribution of planning and executing of movement
What influence the generation of movement?
Local circuits in the spinal cord and brainstem
In Corticospinal, 90% of axons decussate to enter?
Lateral funiculus on the opposite side, and form lateral corticospinal tract
Function of Ventral corticospinal tract
- Voluntary control of the proximal and axial muscles
- involved in balance, posture, and locomotion
Where are Premotor cortex located? and distributed?
- Premotor Cortex are located anterior to the pre central gyrus and anterior paracentral gyrus
- Distributed along the lateral and medial convexity of the caudal frontal lobe
Premotor Area are active in which 2 tasks
- Preparation to move
- control of proximal limb muscle during postural adjustment
Function of Primary somatomotor cortex
Execution of voluntary movement
Output of Premotor Area & Supplementary Motor Area
- Primary Motor Cortex
- Brainstem (via corticobulbar tract)
- Spinal Cord (via corticospinal tract)
What control movements or behaviors?
Select regions, not individual muscles
Origin of Corticospinal
- Primary Somatomotor cortex
- Premotor and Supplementary motor area
- Other cortical regions
Premotor Cortex include which 5 areas?
Premotor Area
Supplementary motor area
Cingulate Cortex
Function of lateral corticospinal tract
- Voluntary control of the distal muscles
- Essential for discrete finger movement
Force of movement is encoded by?
the firing rate
What is the orientation of Cingulate Cortex
- Inferior to the medial convexity
- Dorsal to Corpus Callosum
Anterior Paracentral Gyrus
Lower Extremity
Precentral Gyrus
Dorsal Lateral: Upper Extremity
Lateral: Face
Mirror Neurons are active during?
- Performance of a motor act
- Observation of a motor act
In premotor cortex, neurons are active during?
Mental rehearsal of movement
Middle Cerebral artery supports?
Lateral Complexity
Representation or size of body parts reflects?
Number of neurons innervating the muscles of the body part
Changes of representation of body parts depend on?
Horizontal connections and Local inhibitory circuits
Function of Frontal Eye Fields
Direct voluntary and memory guided movements
When are neurons active in primary somatomotor cortex?
In advance and during movement
What are the inputs to Primary Somatomotor Cortex?
- Premotor cortex - plan for movement
- Primary Somatosensory Cortex & Posterior Parietal Cortex
- Basal Ganglia & Cerebellum - Modulatory input
What is the output of Primary Somatomotor Cortex?
Descending System
Representation of body parts can change based on?
Motor Experience
What is the main function of Premotor Cortex?
Plan Movement
Which Gyrus in Primary Somatomotor Cortex is medial?
Anterior Paracentral Gyrus
Apraxia
- Disconnection between Posterior Parietal Cortex and Premotor Cortex
- Inability to perform sequences of muscle contraction
Where does Ventral Corticospinal Tract Terminate?
Bilaterally on the medial region of the ventral horn
What is the muscle field of the upper motor neuron?
A single upper motor neuron synapse with several lower motor neuron pools that innervate multiple muscles
Anterior Cerebral Artery supports?
- Medial Surface of the hemisphere
- the legs
Lesions of the primary somatomotor cortex / CVA
- Loss of fractionation of movement
- inability to perform discrete finger movements
- contralateral weakness
Premotor Area
Lateral
Supplementary motor area
Medial
Direction of Movement is encoded by?
- Population code
- discharge rate of a group of neurons that are functionally related
Supplementary Motor Area are active during what type of movements?
Sequential and bimanual movements
Lesions of Supplementary Motor Area reduce the?
number of self-initated or spontaneous movements
Intention input from?
Prefrontal Cortex
Voluntary motor control involves what type of processing?
Serial and parallel
Majority of Lateral Corticalspinal Tract are on
Interneurons in local spinal circuits
Premotor Area are active during? Supplementary Motor Area are active during?
- Premotor Area are active during externally generated behavior (visual stimuli)
- Supplementary Motor Area are active during Internally generated behavior (memory)
Where does Lateral Corticospinal Tract terminate?
Contralaterally on the dorsolateral region of the ventral horn
Hemispatial (contralaral) neglect syndrome
lesion of the right parietal lobe
inability to attent to objects
Subset, including Betz cells terminate on?
Primarily flexors on the forearm and hand
In Area 7, neurons are active when
Reaching for an object when the eyes are fixated on it
Lesions of Premotor area impair ability to?
perform visually cued tasks
Input to Premotor Area & Supplementary Motor Area
Prefrontal cortex -intention
Primary Somatomotor Cortex & posterior parietal cortex - sensory information
In Premotor Cortex, neurons are active?
Before and during movements
What makes up Broca’s Area
Inferior Frontal Gyrus - Pars Opercularis & Pars Triangularis
What makes up Frontal Eye Fields?
Middle Frontal Gyrus - Caudal Portion
In Area 5, neurons are active when
reaching for an object when the hand is exploring it
Origin of corticobulbar
Lateral aspect of Primary Somatomotor cortex
How does Corticobulbar terminate?
Bilaterally on interneurons in the reticular formation adjacent to CN
Which nucleus are bias in favor on contralateral input from corticobulbar
- Trigeminal
- Lower Facial
- Hypoglossal
Corticobulbar does not supply which three craniel nerves?
CN 3, 4, 6
What is the main function of corticobulbar?
Voluntary movement of the region of the head
Lower Facial Drool
Lesion of the head region of the primary motor Cortex or the corticobulbar system
Lesions within any level of the brainstem may produce? depending on?
Corticospinal and Corticobulbar signs, depending on the level of brainstem involved and what CN is damaged
Corticospinal signs accompanied by craniel nerve signs are a hallmark of?
Brainstem lesions
What is the best localizing sign and why?
Cranial Nerve deficit, because it provides precise location and level of the lesions
Corticorubral Tract
- Origin: Primary motor cortex, premotor cortex, posterior parietal cortex
- Termination: Red nucleus in the mid brain
Corticoreticular
- Origin: premotor cortex
- Termination: Pontines & Medullary reticular Nuclei
- Function: Postural control
Corticopontine Tract
- Origin: All regions of Cerebral Cortex
- Termination: Basilar Pontine Nuclei