Motor System Part 1 Flashcards
Is motor function an isolated process?
No it is integrated with sensory
What is the motor system?
Allows normal movements to occur
Smooth accurate movement, suppression of unwanted movements
Requires communication between brain
What are the 4 components of the motor system?
From first to most deep:
UMN
LMN
Basal ganglia
Cerebellum
What are the upper motor neurons?
Pyramidal tracts
What are the lower motor neurons?
Receives input from the UMN to innervate the muscle
What is the basal ganglia?
Refines the movement so that it is neither excessive or inadequate
What is the cerebellum?
Programs and coordinate the movement
Describe the pathway of UMN?
Begins in frontal lobe’s motor areas
UMN influence LMN in brainstem (cranial nerves) or spinal cord (spinal nerves)
2 different muscle control pathways one cranial (head) one spinal (below head)
What are the 2 UMN pathways called?
Corticospinal
Corticobulbar
Describe the corticospinal pathway.
Descends to spinal cord to influence the ventral roots of spinal nerves
Describe the corticobulbar pathway.
Descends to the brainstem to influence cranial nerves
Not all cranial nerves have motor functions
What commands do LMN carry? What do they include in the somatic motor system?
Carry commands to the contractile units of voluntary muscles so that movement occur
Spinal nerves and their nuclei
Cranial Nerves and their nuclei
From where do the UMN and LMN receive additional input?
Basal ganglia, cerebellar, and brainstem motor centers
Describe the basal ganglia motor center.
Located in deep cerebrum
Allow desired movements
Postural adjeustments
Prevents undesired movements
Describe the cerebellar motor center.
Fine tunes via connection to cortex and brainstem motor centers
Describe the brainstem motor centers.
Integrates movements of eye and head structures
Can movement ever just involve on muscle pathway?
NO!!!
What system plays a large role in integrating movements (balance)?
Vestibular system
How does fine tuning of movement occur during integration?
Via connections from cerebellum with motor cortex and brainstem motor centers which influence LMNs
How are movements integrated in UMN and LMN?
Muscle receptors send info back to LMN and cerebellum during movement to fine tune and coordinate movement as it proceeds