Neuro Exam 4.1
Card Set Information
Neuro Exam 4.1
neurology neuroscience neuroanatomy
review of neuro part 1 for exam 4
All paths lead to:
lower motor neuron
What is the function of motor control systems?
tell LMN (alpha and gamma MN) what to do
What is the end result of motor control systems?
instruct LMN to fire or not to fire
How many motor control systems are there?
What are the names of the motor control systems?
Are the motor control systems integrated?
yes, highly integrated (play off each other and can't work alone!)
Describe the pyramidal motor control system:
initiated, voluntary skeletal muscle activity
Describe the extrapyramidal motor control system:
involuntary skeletal muscle activity (instinctive, reflexive)
What are both motor control systems trying to get the attention of?
Which motor control system is the supplemental motor area a part of?
In which lobe is the supplemental motor area located?
The supplemental motor area is anterior to:
pre-central gyrus (PCG)
The supplemental motor area is superior to:
What is the supplemental motor area functionally?
an association area
What are association areas?
interact with pre-central gyrus using association fibers
What is the supplemental motor area important for?
initiation of movement
The supplemental motor area is involved with:
orientation of eyes and head (extrinsic eye m coordination)
What does the supplemental motor area plan?
sequential and bi-manual movements (like tying shoes)
What does the supplemental motor area interact with?
Where does the supplemental motor area send UMN to?
cranial N mtor nuclei
ventral horns of SC where UMN synapse with LMN
When the supplemental motor area sends UMN to CN motor nuclei, which tract does it use?
When the supplemental motor area sends UMN to ventral horns of SC, which tract does it use?
The supplemental motor area sends UMN to ventral horns of SC where UMN synapse with LMN. Where does the LMN go to?
What is the main function of supplemental motor area?
finesse what precentral gyrus does
Which system is the pre-motor area a part of?
Which lobe is the pre-motor area in?
The pre-motor area is anterior to:
What is the pre-motor area functionally?
What does the pre-motor area control?
trunk, pelvic, and pectoral girdle musculature (changing posture; stabilization)
What is the pre-motor area involved with?
anticipatory postural control and adjustments
What does the pre-motor area interact with?
UMN to CN motor nuclei in brain stem UMN to ventral horns (SC) via corticospinal
Which system is the broca's area a part of?
Which lobe is the broca's area located in?
What is the Broca's area anterior to?
precentral gyrus (in area of pre-motor cortex)
What is the Broca's area functionally?
What is the primary function of the Broca's area?
What are the types of motor tracts?
cranial nerve tracts
modulatory descending motor tracts
Are corticofugal motor tracts LMNs or UMNs?
How many types of corticofugal tracts are there?
What are the 2 types of corticofugal tracts?
Which motor control system is the corticospinal tract a part of?
What does the corticospinal tract control?
voluntary contralateral skeletal muscle activity from the extremities and trunk
Is the corticospinal tract bilateral or unilateral?
How many neurons make up the corticospinal tract?
2 neuron pathway
Where are the cell bodies of the UMNs of the corticospinal tract located?
pre-central gyrus (primary motor cortex) of frontal lobe
Where do the UMNs that collectively form the corticospinal tract go?
descend through posterior limb of internal capsule (PLIC)
through crus cerebri of cerebral peduncles of midbrain
through ventral pons (longitudinal fibers) and into ventral medulla
What happens after the UMNs of the corticospinal tract reach the medulla?
90% decussate in pyramids of medulla
10% do not decussate in the pyramids
Where do the 90% of UMNs in the corticospinal tract that decussate in the pyramids of the medulla descend?
contralateral lateral white column of SC
What are the 90% of UMNs in the corticospinal tract that decussate in the pyramids of the medulla called as they descend?
lateral corticospinal tract
Where do the lateral corticospinal tract fibers synapse with LMNs?
Where do the 10% of UMNs in the corticospinal tract that don't decussate in the pyramids go?
continue ipsilateral descent via ventral white column of the SC
What are 10% of UMNs in the corticospinal tract that don't decussate in the pyramids called as they descend?
ventral corticospinal tract
Where does the ventral corticospinal tract decssate?
via anterior white commissure (ventral spinal cord) to contralateral side
Where do the ventral corticospinal tract fibers synapse with LMN?
Where do the LMN go?
out through spinal nerve to innervate skeletal mm via peripheral nn
As a result of the 90/10 decussation pattern, the corticospinal tract never experiences:
a complete lesion
Stroke via R anterior cerebral artery will damage:
UMN in R hemisphere
contralateral effect=problems on the L side of the body
Spinal cord accident that wipes out the corticospinal tract in the spinal cord on L side:
ipsilateral effect=problems on L side of body
How do you refer to tracts when it comes to injuries?
either corticospinal tract on R side of spinal cord (and vice versa)