12. Motor III - the Basal Ganglia and Motor Association Cortex

Question 1

key regions for HIGHER MOTOR CONTROL are the CEREBELLUM, BASAL GANGLIA and MOTOR ASSOCIATION CORTICES.

what is the role of the CEREBELLUM

Answer 1

PRECISION OF ACTION

Question 2

what is the role of the BASAL GANGLIA

Answer 2

to AMPLIFY MOVEMENT
- controls the AMOUNT of movement

Question 3

what is BRADYKINESIA

Answer 3

TOO LITTLE (or too slow) MOVEMENT

• fault at BASAL GANGLIA

Question 4

what is DYSKINESIA

Answer 4

TOO MUCH MOVEMENT

• fault at BASAL GANGLIA

Question 5

what is the role of the MOTOR ASSOCIATION CORTICES

Answer 5

SELECT THE CORRECT ACTION (PRAXIS)

Question 6

LOSS of FUNCTION of CEREBELLUM:

Answer 6

ATAXIA

Question 7

LOSS of FUNCTION of BASAL GANGLIA:

Answer 7

BRADYKINESIA or DYSKINESIE

Question 8

LOSS of FUNCTION of BASAL GANGLIA:

Answer 8

BRADYKINESIA or DYSKINESIA

Question 9

LOSS of FUNCTION of MOTOR ASSOCIATION CORTICES

Answer 9

APRAXIA

Question 10

WHERE is the BASAL GANGLIE

Answer 10

in the CENTRE of the FOREBRAIN (deep part)

• ANTERIOR to THALAMUS

Question 11

BASAL GANGLIA are …. MATTER STRUCTURES

Answer 11

GREY MATTER STRUCTURES

/ a group of NUCLEI

Question 12

BASAL GANGLIA GREY MATTER is traversed by WHITE matter creating a STRIPY APPEARANCE known as:

Answer 12

CORPUS STRIATUM

Question 13

parts of the CORPUS STRIATUM of the BG:

Answer 13

• NEOSTRIATUM : CAUDATE (nucleus) & PUTAMEN
• GLOBUS PALLIDUS (external and internal)

Question 14

BASAL GANGLIA also includes two other parts besides the Corpus Striatum that are not part of the basal ganglia proper (located outside):

Answer 14

• SUBTHALAMIC NUCLEUS (lower Diencephalon)
• SUBSTANTIA NIGRA (Midbrain)

Question 15

where is the SUBTHALAMIC NUCLEUS

Answer 15

in the LOWER DIENCEPHALON
(area between brainstem and cerebrum)

Question 16

where is the SUBSTANTIA NIGRA

Answer 16

MIDBRAIN

Question 17

SUBSTANTIA NIGRA (PARS COMPACTA) consists of BLACK STAINING CELLS. why do they get this black colour

Answer 17

BY-PRODUCT of SYNTHESISING their main neurotransmitter : DOPAMINE

Question 18

DOPAMINE is produced in the SUBSTANTIA NIGRA of the BASAL GANGLIA. what does it do?

Answer 18

ENAHNCE MOVEMENT / ACTVITY in BASAL GANGLIA of BRAIN

• have MODULATING EFFECTS (adjust amplification of movement)
• has role in brains REWARD CENTRE (feeling of reward)

Question 19

LACK OF DOPAMINE (due to loss of dopaminergic cells in Substantia Nigra) results in what disease

Answer 19

PARKINSON’S DISEASE

• with SLOWING of MOVEMENT (BRADYKINESIA) and TREMOR

Question 20

DOPAMINE is what type of NEUROTRANSMITTER

Answer 20

AMINE

Question 21

HUNTINGTON’S DISEASE is caused by what

Answer 21

ATROPHY / DEGENERATION OF CORPUS STRIATUM

• causing EXCESSIVE MOVEMENT (DYSKINESIA)
• LOSS of INHIBITORY EFFECTS on the THALAMUS and CORTEX

Dance-like Dyskinesia in HD is called CHOREA

Question 22

INHIBITORY OUTPUT to the THALAMUS comes from which part of the BASAL GANGLIA

Answer 22

GLOBUS PALLIDUS INTERNAL

Question 23

there are both DIRECT and INDIRECT PATHWAYS of the BASAL GANGLIA.

which pathway has a STIMULATORY / EXCITATORY EFFECT on the THALAMUS -> CORTEX

Answer 23

DIRECT PATHWAY

SUBSTANTIA NIGRA
-> NEOSTRIATUM
-> GLOBUS PALLIDUS INTERNAL

-> THALAMUS -> CORTEX

(as two negatives make a positive, so two inhibitory effects create excitatory effect)

Question 24

INDIRECT PATHWAY of BASAL GANGLIA has GLOBUS PALLIDUS EXTERNAL after the STRIATUM and before the GLOBUS PALLIDUS INTERNAL so 3 negatives make a … effect

Answer 24

INHIBITORY

Question 25

NIGROSTRIATAL PATHWAY starts from the SUBSTANTIA NIGRA to the STRIATUM. which RECEPTORS does DOPAMINE act on for the DIRECT PATHWAY, POSITIVE NEUROMODULATORY EFFECT

Answer 25

D1 RECEPTORS

Question 26

DOPAMINE on D2 RECEPTORS of STRIATUM activate what effect

Answer 26

INHIBITORY NEUROMODULATORY EFFECTS - INDIRECT PATHWAY (striatum -> globus pallidus external -> globus pallidus internal)

Question 27

SUBSTANTIA NIGRA of the MIDBRAIN has two parts

Answer 27

- main functional part: PARS COMPACTA with DOPAMINERGIC CELLS (tight together) - PARS RETICULIS - basic part, network of cells

Question 28

DAMAGE to the SUBTHALAMIC NUCLEUS in the DIENCEPHALON causes..

Answer 28

BALLISMUS

Question 29

THALAMUS is the station for what

Answer 29

SENSORY RELAY STATION & RELAY STATION of MOTOR FEEDBACK from Cerebellum and Basal Ganglia

Question 30

NEOSTRIATUM consists of 3 functional parts (1 is small and less important)

Answer 30

- PUTAMEN : MOTOR PROCESSING - CAUDATE : PLANNING MOVEMENT & BEHAVIOUR - NUCLEUS ACCUMBENS : EMOTIONAL OUTPUT

Question 31

what causes PARKINSON'S DISEASE

Answer 31

LACK OF DOPAMINE from SUBSTANTIA NIGRA

Question 32

ATROPHY of ... causes HUNTINGTON'S

Answer 32

CORPUS STRIATUM of the Basal Ganglia

Question 33

which part of the NEOSTRIATUM is involved in MOTOR PROCESSING

Answer 33

PUTAMEN

Question 34

what are the MOTOR ASSOCIATION CORTICES:

Answer 34

- PRIMARY MOTOR CORTEX (BA 4) - PREMOTOR CORTEX (BA 6) - SUPPLEMENTARY MOTOR CORTEX (BA 6)

Question 35

where is the PRIMARY MOTOR CORTEX (which brodmann's area)

Answer 35

BA 4

Question 36

where are the PREMOTOR CORTEX and SUPPLEMENTARY MOTOR CORTEX (both premotor cortices)

Answer 36

BA 6 Premotor cortex: MEDIAL Supplementary motor cortex: LATERAL

Question 37

which is the DIFFERENCE between the PRIMARY MOTOR CORTEX (BA 4) and PREMOTOR CORTICES (BA 6)

Answer 37

PREMOTOR CORTICES (BA 6) require much STRONGER STIMULI (small stimulus won't generate movement) and the triggered movements are MORE COMPLEX BA 4 only needs a small stimulus and movements are less complex

Question 38

medial parts of BA 6 seem to be crucial in.. Lateral parts of BA 6 seem to be crucial in..

Answer 38

- Medial: IMAGINED, SELF-INITIATED MOVEMENTS - Lateral: Movements undertaken in relation to a sensory cue ie light at a particular position

Question 39

when is a MIRROR NEURON Active

Answer 39

both when making / planning the movement and when WATCHING THE MOVEMENT (someone doing the movement)

Question 40

MOTOR ASSOCIATION CORTICES are for PRAXIS. what does PRAXIS refer to

Answer 40

range of higher motor functions which involve SELECTION of the CORRECT MOVEMENT Deficiency: APRAXIA / DYSPRAXIA

Question 41

where are the MOTOR ASSOCIATION CORTICES

Answer 41

CORTEX OF FOREBRAIN