Chapter 5

Question 1

basal ganglia located all over the brain but all have one thing in common

Answer 1

• prepare the starting and stopping of voluntary motions, by means of direct and indirect pathways for motor movements
• work together

Question 2

major components of basal ganglia

Answer 2

• caudate and putamen (striatum)
• globus pallidus
• subthalamic nucleus
• substantia nigra
• nucleus accumbens

Question 3

basal ganglia striatum

Answer 3

caudate nucleus and putamen

Question 4

direct pathways for motor movements in the basal ganglia

Answer 4

implicated in functions concerned with the initiation (or excitation) of motor movements

Question 5

indirect pathways for motor movements in the basal ganglia

Answer 5

implicated in the stopping (or inhibition) of motor movements

Question 6

movement disorders (basal ganglia disorders) classified into two broad categories

Answer 6

hyperkinetic disorders and hypokinetic disorders

Question 7

hyperkinetic disorders

Answer 7

when the excitatory pathways become overactive relative to the inhibitory pathways

Question 8

hypokinetic disorders

Answer 8

when the inhibitory pathways become overactive relative to the excitatory pathways

Question 9

substantia nigra divided into two parts

Answer 9

pars compacta (SNc) and pars reticulata (SNr)

Question 10

pars compacta (SNc) of the substantia nigra

Answer 10

source to one of the major domaince projections, the nigrostriatal pathway (from SNc to neostriatum)

Question 11

pars reticulata (SNr) of the substantia nigra

Answer 11

mostly GABA (inhibitory) neurons to thalamus

Question 12

dopamine

Answer 12

excitatory

Question 13

GABA

Answer 13

inhibitory

Question 14

Parkinson’s Disease

Answer 14

• movement disorder
• results from the degeneration of the pars compacta neurons
• characterized by: muscle rigidity, bradykinesia/akinesia, resting tremor
• most common treatment is replacement therapy with L-DOPA, a precursor of dopamine
• can treat by lesioning part of the pars compacta (SNc) to reduce inhibition of dopamine

Question 15

hypokinetic disorder

Answer 15

Parkinson’s disease

Question 16

stages of progression of physical signs of Parkinson’s disease

Answer 16

• stage 1: unilateral movement; early masking of facial expression, affected arm in semiflexed position with tremor
• stage 2: bilateral involvement with early postural changes; slow, shuffling gait with decreased excursion of legs
• stage 3: pronounced gait disturbances and moderate generalized disability; postural instability with tendency to fall

Question 17

hyperkinetic disorders

Answer 17

• Huntington’s disease
• Hemiballismus
• Athetosis

Question 18

nigrostriatal pathway

Answer 18

from the substantia nigra in the midbrain, dopamine, to the caudate/putamen (straitum)
- initiate movement

Question 19

reverse of nigrostriatal pathway

Answer 19

from the caudate/putamen (striatum), GABA, to the substantia nigra
- stop movement

Question 20

Huntington’s Chorea

Answer 20

symptoms include:
- involuntary jerking or fidgety movements of the limbs and body
- stumbling and clumsiness
- cognitive impairment: difficulty planning and determining the direction of movement
- emotional and motivational issues: difficulty controlling the emotional and motivational aspects of movement

• no caudate, so no GABA –> over-movement

Question 21

Hemiballismus

Answer 21

• onset can occur at any age and always due to stroke
• damage in subthalamic nucleus (STN) or globus pallidus (GPc)
• severe contralateral flinging movements (arms or legs)