Lecture 4- Motor Systems of Brain

Question 1

Muscle control uses what tract?

Answer 1

Corticospinal (Pyramidal) tract

Question 2

Pathway of corticospinal tract

Answer 2

Upper motor neuron in 1. Motor cortex ( pyramidal cells)
Down internal capsule
Down pyramidal/corticospinal tract
Pyramidal Decussation occurs at Medullary Pyramids
Inter neuron transfers to Lower motor neuron

Question 3

General rule for position of motor and sensory info

Answer 3

Motor is Carried further forward

Question 4

Decussation?

Answer 4

Pyramidal Decussation occurs where 85% goes to the lateral corticospinal tract(and enters the spinal cord)
15% uses the central/anterior corticospinal tract and crosses over at individual spinal segmental level(axial muscle posture possibly)

Question 5

Issue with upper motor neuron?

Answer 5

Spastic paralysis

• increased muscle tone as UMM controls reflex arc and LMN
• decrease in control or fine movements

Question 6

Issue with Lower Motor Neuron

Answer 6

Flaccid Paralysis

-removes all control of muscle and decreases muscle tone

Question 7

Pons structure

Answer 7

An enlargement due to lots of structures that have nerves going to them and going out to the face

Question 8

Control system of the motor pathway uses the?

Answer 8

Basal Ganglia of the sub-cortical gray matter

Question 9

Basal ganglia consists of

Answer 9

Caudate nucleus
+Putamen = Striatum
Internal and external segments of the Globus Pallidus
Substantia Nigra -(pars compacta and pars reticula)
Putamen + GP=lenticular nucleus
ALL BILATERAL STRUCTURES

Question 10

The basal ganglia system used for

Answer 10

Initiation of movement
Fine motor control
Mood through movement
Suppress unwanted movement

Question 11

Cerebellum cortex is used for and is_____?

Answer 11

Uses glutamate
Termination of movement 
Coordination of movement
Ballistic(fast unplanned) movement 
IPSILATERAL

Question 12

Uses of the Basal Ganglia

Answer 12

Influence muscle tone by the Globus Pallidus sending impulses into the reticular formation that reduce muscle tone

Influence many aspects of cortical function, including: sensory, limbic, cognitive(attention, memory, planning) and linguistic function

Question 13

Cycle of control and muscle movement refinement

Answer 13

Upper motor neuron sends info to striatum( cordate nucleus + Putamen)
Neuron to Globus Pallidus clarifies movement
Globus Pallidus to VENTRAL ANTERIOR - VENTRAL LATERAL of the Thalamus (uses inhibitory GABA)
Suppresses glutamate activity of thalamus— planning fibre