Unit 3: Basal Ganglia Pg 113 - 116

Question 1

A collection of nuclei within telencephalon and brainstem that function in control of motor activity

Answer 1

Basal ganglia

Question 2

Anatomy of basal ganglia

Answer 2

1. Caudate
2. Putamen
3. Globus pallidus
4. Substantia nigra (midbrain)
5. Subthalamic nucleus

1+2 = (Neo)striatum
1+2+3 = corpus striatum
2+3 = lentiform (lenticulate nucleus)

Question 3

Input into basal ganglia circuts are directly from ____ and indirectly from ____

Answer 3

Directly — cerebral cortex; Indirectly — thalamus

Question 4

What receives most of the input into the basal ganglia?

Answer 4

Curate and putamen

Question 5

Much of the output of teh caudate and putamen (striatum) is to

Answer 5

Globus pallidus (pallidum)

Question 6

Neostratum made up of

Answer 6

Caudate and putamen

Question 7

Corpus striatum made up of

Answer 7

Caudate
Putamen
Globus pallidus/pallidum

Question 8

Lentiform / lenticulate nucleus made up of

Answer 8

Putamen

Globus pallidus

Question 9

Most efferent output of basal ganglia is by

Answer 9

Neurons of globus pallidus

Question 10

Fibers from globus pallidus project to

Answer 10

Ventral lateral (VL) and ventral anterior (VA) nuclei of thalamus

Question 11

Fibers from globus pallidus going to neurons of VL/VA nucleus do what

Answer 11

inhibit neurons of VL/VA nucleus

Question 12

neurons of VL/VA nuclei send axons to

Answer 12

Motor cortex

Question 13

When no movements are being made, what is happening in basal ganglia? Think striatum, globus pallidus, etc

Answer 13

Neurons of striatum are quiet and thus not inhibiting globus pallidus

Neurons of globus pallidus are active and therefore inhibiting neurons of VL/VA nuclei

No facilitation of motor cortex = no movement

Question 14

Shortly before or during a movement, what is happening in basal ganglia? Think striatum, globus pallidus, etc

Answer 14

Neurons of striatum are active and inhibit neurons of globus pallidus

So globus pallidus is NOT inhibiting VL/VA nuclei

Therefore VL/VA nuclei is active and neurons of VL/VA nuclei stimulate motor cerebral cortex and modifies its output

Question 15

What is important for storage of instructions for fragments of movements that are learned?

Answer 15

Corpus striatum

Question 16

Lesions of basal ganglia results in

Answer 16

Abnormal involuntary movements that are displayed on side of the body contralateral to lesion

Question 17

Resulting movements from basal ganglia lesion are termed

Answer 17

Dyskinesias and Dystonias

Question 18

Athetoid movements = athetosis

Answer 18

Snake-like involuntary movements

Question 19

Athetoid movements = athetosis is usually associated with damage to the

Answer 19

Striatum (especially putamen)

Question 20

Choreiform movements = chorea

Answer 20

Irregular, brisk, jerky, small amplitude, involuntary

Question 21

Choreiform movements are usually associated with damage to

Answer 21

The striatum (especially caudate)

Question 22

Chorea is associated with

Answer 22

Huntington’s disease

Question 23

Ballismus = ballistic movements

Answer 23

Wild, forceful, flinging, large amplitude

Question 24

Ballismus is associated with damage to

Answer 24

Subthalamic nucleus

Question 25

Parkinson’s disease

Answer 25

Paralysis agitans

Question 26

Parkinson’s disease characteristics

Answer 26

Resting tremor Muscular rigidity Bradykinesia, can lead to shuffling gait and masked face

Question 27

Bradykinesia

Answer 27

Poverty of movement. Masked face. Decreased pendulum movement during gate = shuffling feet.

Question 28

What is associated with degenerative changes in substantia nigra and/or depletion of dopamine?

Answer 28

Parkinson’s disease

Question 29

Why is dopamine important?

Answer 29

Nigral-striatum neurons of substantia nigra use dopamine