Motor Flashcards
What does the cortex send to the spinal cord?
Direct and indirect projections
-Corticospinal and corticovulbar/bulbospinal
How is movement initiated?
In the basal ganglia which projects to the motor cortex
What is movement regulated by?
The cerebellum which projects to the motor cortex
What does the cerebral cortex consist of?
Primary motor cortex, premotor cortex, Broca’s area, Frontal eye field
Describe the frontal eye field.
Number 8
Voluntary movements of the eyes
Describe Broca’s area.
Numbers 44 and 45
One side only- typically the left
motor speech area
Think Broca Broadcasting
Describe the premotor cortex.
Anterior to precentral gyrus (6)
Coordinates simultaneous movement of many muscle groups
Describe the primary motor cortex.
Precentral gyrus (4) of the frontal lobe
Related to the somatosensory cortex (3,2,1)
What region of the brain activates as we think about movement?
Example: When I think about getting up to pee while laying in bed
The supplementary motor
WWhat is the purpose of descending motor pathways?
Descending tracts deliver efferent impulses from the brain to the spinal cord
What are the two groups of descending tracts?
Direct pathways aka pyramidal tracts
Indirect pathways aka any other tract
How many neurons do motor pathways involve? What are they?
Two- One upper in the motor cortex and one lower that is a spinal/cranial nerve motor neuron
How many neurons do motor pathways involve? What are they?
Two- One upper in the motor cortex and one lower that is a spinal/cranial nerve motor neuron
Where do direct pathways originate?
In the precentral gyri with pyramidal neurons
Where are impulses sent in the direct system?
Through the corticospinal tracts and synapse in the anterior horn
What activates skeletal muscles?
Stimulation of anterior horn neurons
What part of the direct pathway innervates the cranial nerve nuclei
Corticobulbar tracts
What does the direct pathway regulate?
Fast and fine skilled movents
What does a motor unit consist of?
The efferent branches of the axon of a spinal/cranial motor neurons and all the muscle fibers that it innervates