control of movement

Question 1

what does the descending spinal tract do?
and what are the two major pathways

Answer 1

pathways in the spinal cord that transmit motor signals from brain to muscle. found mostly in cerebral cortex

pathways = lateral
-ventromedial

Question 2

what is the lateral pathway associated with
-what are the 2 key tracts in lateral pathway
1) corticospinal tract (pyramidal tract)
2) rubrospinal tract

Answer 2

controls voluntary movment of limbs

1) controls voluntary movments of limbs
2) controls voluntary movment of upper limbs

Question 3

the effects of corticospinal lesions
-recovery

Answer 3

deficit movment of arms and hands.
-recovery if rubrospinal tract intact

Question 4

what does the ventromedial pathway do.
the three pathways associated with it
1) vestibulospinal tract
2) tectospinal tract
3) recticulospinal tract

Answer 4

controls posture, balance and locomotion
1) head balance and turning
2) coordinated head and neck movements
3) muscle tone, posture and automatic movments (two parts pontine and medullary)

Question 5

describe the two branches in recticulospinal tract of ventromedial pathway (reflex)
1) pontine
2) medullary

Answer 5

1) helps posture by reflex
2) inhibits muscles from reflex but helps flexor muscle activity for coordination of locomotion

Question 6

primary structures of limbic system
amygdala - hippocampus - thalamus - hypothalamus - basal ganglia - cingulate gyrus

Answer 6

amygdala- emotion centre of brain
hippocampus- foramtion of memories and past experience
basal ganglia- selection and initation of willed movments

Question 7

basal ganglia disorders
-parkinsons disease
-huntintons disease (hemiballismus)

Answer 7

• trouble with willed movments. due to degeneration of dopamine in substantia nigra inputs to striatum

-hemiballismus: voilent flinging movements on one side of the body

Question 8

what is the control of saccadic eye movements by the superior colliculus

Answer 8

rapid eye movements that allow us to shift our focus from one thing to another

Question 9

function of cerebellum and cerebellar lesions
-ataxia
-dysynergia
-dysmetria

Answer 9

motor control, coordination, muscle contractions

-uncoordinated and inaccurate movments
-decomposition of synergistic multijoint movements
-overshoot or undershoot target