BASAL GANGLIA

Question 1

Role of basal ganglia

Answer 1

complex motor action

Question 2

role of cerebellum

Answer 2

movement coordination

Question 3

basal ganglia refer to

Answer 3

refers to a large and functionally diverse set of nuclei that lies deep within the cerebral hemispheres.

Question 4

what are the 5 nuclei of basal ganglia

Answer 4

Caudate
Putamen
Globus Pallidus
Substantia Nigra
Subthalamus

Question 5

how does basal ganglia influence movement

Answer 5

by regulating the activity of the upper motor neuronal circuits:

Regulate muscle contraction,
Force initiation and termination of movement,
Regulate multi-joint movements,
Control movement sequencing,
Oculomotor control (e.g. saccadic eye movement),
Motor habit learning.

Question 6

where is the input zone on the basal ganglia

Answer 6

striatum -> putamen

Question 7

striatum receive and process movement-related signal from

Answer 7

Cerebral cortex,
Substantia nigra pars compacta (dopaminergic neurons).

Question 8

what is the main neuron of the caudate and putamen

Answer 8

medium spiny neurons (inhibitory, GABA).

Question 9

Axons from medium spiny neurons contact neurons of:

Answer 9

Globus pallidus (External & Internal),
Substantia nigra pars reticulata (not SN pars compacta).

Question 10

Axons from medium spiny neurons contact neurons of:

Answer 10

Globus pallidus (External & Internal),
Substantia nigra pars reticulata (not SN pars compacta).

Question 11

location of inhibitory of globus palidus

Answer 11

Ventral anterior and ventral lateral complex nuclei of the thalamus

Question 12

location of excitatory of globus palidus

Answer 12

Motor cortex on the frontal cortex (upper motor neurons).

Question 13

Efferent cells of globus pallidus internal and substantia nigra pars reticulata are excitatory or inihibitory

Answer 13

inhibitory

Question 14

role of Efferent cells of globus pallidus internal and substantia nigra pars reticulata

Answer 14

They have high levels of spontaneous activity that prevent unwanted movement by tonically inhibiting cells in the thalamus and superior colliculus.

Question 15

role of direct pathway of BG

Answer 15

serves to release the thalamic neurons from tonic inhibition practiced by the globus pallidus to facilitate the initiation of voluntary (intended) movement.

Question 16

role of indirect pathway of BG

Answer 16

serves to increase the level of tonic inhibition of the thalamic neurons in order to prevent unwanted movement.

The indirect pathway can thus be regarded as a “brake” on the normal function of the direct pathway “accelerator”.

Question 17

principal function of direct pathway of BG in motor control

Answer 17

facilitates the initiation of motor programs that express movement (i.e., promotes voluntary movement in targeted muscles).

Question 18

principal function of indirect pathway of BG in motor control

Answer 18

facilitates the suppression of competing or non-synergistic motor programs (i.e., inhibits movement in other muscles that do not contribute to overall wanted movement).
Thus, generating smooth and coordinated movements.

Question 19

what can explain parkinson and huntigton disease

Answer 19

Dysfunctions in the two pathways of BG

Question 20

The basal ganglia serves to program movement but also

Answer 20

cognitive and emotional operation