Neuroanatomy 3: Basal Ganglia and Cerebellum

Question 1

What is the role of the cerebellum?

Answer 1

Involved in planning intended movement in motor cortex and feeding it to the CST for movement to occur

Question 2

What is the basal ganglia? What is their role?

Answer 2

Series of grey matter structures key to initiation and inhibition of movement
Role in posture and muscle tone

Question 3

How is white and grey matter distributed in the cerebellum?

Answer 3

Core of white matter

Grey matter outside

Question 4

What exists anterosuperiorly, posteriorely and superiorly to the cerebellum respectively?

Answer 4

Cerebral hemispheres
Pons and medulla
Lateral fissure

Question 5

List the lobes that combine to form the cerebellum

Answer 5

Anterior
Posterior
Floccolus (‘ear’) - part of flocculonodular lobe

Question 6

List the fissures that exist within the cerebellum and give their position

Answer 6

Primary (between anterior and posterior)

Horizontal (splits posterior)

Question 7

What cavity does the cerebellum exist within? What cavities exists superiorly and posteriorly to this?

Answer 7

Tentorium cerebelli
Falx cerebri
Falx cerebelli

Question 8

How is the cerebellum attached to the brainstem?

Answer 8

Via 3 peduncles - superior, middle and inferior cerebellar peduncles

Question 9

Which is the largest cerebellar peduncle?

Answer 9

Middle

Question 10

What parts of the cerebellum can be attributed to its function?

Answer 10

Vermis (line down middle of A and P lobe)

Grey matter within the core (series of nuclei that communicate outputs from the cerebellum)

Question 11

What are the 3 layers of the cortex from outside to inside?

Answer 11

Molecular layer
Purkinje cell layer
Granule cell layer

Question 12

Where do afferent inputs to the cerebellum arrive from? (3)

Answer 12

MOTOR
Spinal cord (via somatic proprioceptors and pressure receptors)
Cerebral cortex (via pons)
Vestibular apparatus via nuclei

Question 13

Where in the cerebellum do afferent projections enter and project to?

Answer 13

Cerebellar peduncle

Granular layer

Question 14

Where does the efferent output from the cerebellum come from? What is the function of this?

Answer 14

Axons of purkinje cells

Coordinate function of all motor tracts

Question 15

Where do efferent outputs from the cerebellum synapse? What happens after this?

Answer 15

Thalamus

Sends fibres to motor cortex

Question 16

A lesion to a cerebellar hemisphere would cause symptoms on the ipsilateral side. True/False?

Answer 16

True

Question 17

What symptoms would we expect from a lesion to a unilateral hemisphere?

Answer 17

Coordination problems - intention tremor, unsteady gait

Question 18

What symptoms would we expect from a lesion to bilateral hemispheres?

Answer 18

Speech problems (Dysarthria)
Gait problems (Ataxic gait)

Question 19

What symptoms would we expect from a lesion to the midline of the cerebellum?

Answer 19

Posture problems - falls over when standing

Question 20

List some basal ganglia

Answer 20

Caudate nucleus
Putamen and globus pallidus (lentiform nucleus)
Subthalamic nucleus
Substantia nigra

Question 21

What is the striatum of the basal ganglia?

Answer 21

Caudate nucleus

Putamen

Question 22

What is the corpus striatum?

Answer 22

Caudate nucleus
Putamen
Globus pallidus

Question 23

What does the lentiform nucleus look like?

Answer 23

Globus pallidus (two stripes)
Putamen (lentil)

Question 24

What does the caudate nuclei look like?

Answer 24

Horn

Question 25

What is located lateral and medial to the internal capsule (white matter tract)?

Answer 25

Lentiform nucleus | Thalamic nuclei

Question 26

What does the substantia nigra look like? Where is it located in the brainstem?

Answer 26

Black lines | Midbrain

Question 27

What disease is characterised by degeneration of dopaminergic neurones of substantia nigra?

Answer 27

Parkinsons Disease

Question 28

What pathway is used to enhance normal movement by the basal ganglia?

Answer 28

Direct pathway | Enhance outflow of thalamus

Question 29

What pathway is used to inhibit unwanted movement by the basal ganglia?

Answer 29

Indirect pathway | Inhibit outflow of thalamus

Question 30

Unilateral lesions of the basal ganglia affect the ipsilateral side. True/ False?

Answer 30

False | Affect contralateral side

Question 31

What symptoms would we expect from a lesion to the basal ganglia?

Answer 31

Change in muscle tone Dyskinesias (abnormal involuntary movement) inc. tremor, chorea (rapid asymmetrical movements typically by the distal limbs), myoclonus (muscle jerks)

Question 32

What symptoms would we expect in Parkinsons Disease?

Answer 32

REDUCED OUTPUT TO CORTEX Akinesia (impairment of the power of voluntary movement) Rigidity Resting tremor

Question 33

What is Huntingdon's Disease?

Answer 33

Progressive degeneration of basal ganglia and cerebral cortex

Question 34

What are the folds in the cerebellum called?

Answer 34

Folia