Guyton Chapter 56 - Contributions Of The Cerebellum And Basal Ganglia To Overall Motor Control

Question 1

What other brain structures than the cerebral cortex stimulate muscle contraction?

Answer 1

Cerebellum
Basal ganglia

Question 2

What helps to plan and control complex patterns of muscle movement?

Answer 2

The basal ganglia

Question 3

What plays a major role in the timing of motor activities and in rapid smooth progression from one muscle movement to the next?

Answer 3

The cerebellum

Question 4

Which lobes does the cerebellum consist of?

Answer 4

Anterior lobe
Posterior lobe
Flocculonodular lobe

Question 5

What zones are the cerebellar hemisphere consisting of?

Answer 5

Intermediate and lateral zone

Question 6

Where does the corticopontocerebellar pathway originate and where does it go?

Answer 6

Originates in cerebral motor and premotor cortices and in the cerebral somatosensory cortex.

Passes pontile nuclei and pontocerebellar tracts mainly to the lateral divisions of the cerebellar hemispheres on the opposite side of the brain from the cerebral areas.

Question 7

Which are the 2 most important tracts that send sensory signals from the peripheral parts of the body to the cerebellum?

Answer 7

Dorsal spinocerebellar tract and ventral spinocerebellar tract

Question 8

The ventral spinocerebellar tract is excited mainly by motor signals arriving in the anterior horns from…?

Answer 8

The brain through the corticospinal and rubrospinal tracts

Internal motor pattern generators in the cord itself.

Question 9

What is the efference copy of the anterior horn motor drive?

Answer 9

The ventral fibre pathway tells the cerebellum which motor signals have arrived at the anterior horns.

Question 10

What is the efference copy of the anterior horn motor drive?

Answer 10

The ventral fibre pathway tells the cerebellum which motor signals have arrived at the anterior horns.

Question 11

What are the 3 cerebellar nuclei called that are located deep in the cerebellar mass?

Answer 11

Dentate
Interposed
Fastigial

Question 12

Which 2 sources do the cerebellar nuclei receive signals from?

Answer 12

The cerebellar cortex
The deep sensory afferent tracts to the cerebellum

Question 13

Which cells does the functional unit of the cerebellum centre on?

Answer 13

Purkinje cell
Deep nuclear cell

Question 14

Which 3 layers of the cerebellar cortex are the major layers?

Answer 14

Molecular layer
Purkinje cell layer
Granule cell layer

Question 15

Which two fibre types create fiber input to the cerebellum?

Answer 15

Climbing fibre type
Mossy fibre type

Question 16

Where do climbing fiber types originate from?

Answer 16

Inferior olives of the medulla

Question 17

What happens with the nuclear cells when stimulated by climbing and mossy fibres as well as Purkinje cells?

Answer 17

Stimulation by climbing and mossy fibres stimulate the nuclear cells and signals from Purkinje cells inhibit them.

Question 18

What are the basket cells and stellar cells?

Answer 18

Inhibitory cells with short axons that are located in the molecular layer of the cerebellar cortex.
Cause lateral inhibition of adjacent Purkinje cells.

Question 19

The nervous system uses the cerebellum to coordinate motor control functions at three levels - which are these?

Answer 19

Vestibulocerebellum
Spinocerebellum
Cerebrocerebellum

Question 20

What does the vestibulocerebellum consist of?

Answer 20

Small flocculonodular cerebellar lobes that lie under posterior cerebellum and adjacent portions of vermis.

Provides neural circuits for most of the body’s equilibrium movements

Question 21

What does the spinocerebellum consist of and what is the function?

Answer 21

Consists of most of the vermis of the posterior and anterior cerebellum plus adjacent intermediate zones on both sides of vermis.

Provides circuitry for coordinating movements of the distal portions of the limbs.

Question 22

What is the cerebrocerebellum and what does it consist of?

Answer 22

Consists of the large lateral zones of the cerebellar hemispheres lateral to the intermediate zones.

Receives information from cerebral motor cortex and adjacent premotor and somatosensory cortices of the cerebrum. Transmits output information in the upward direction back to the brain functioning in a feedback manner with the cerebral cortical sensorimotor system to plan sequential voluntary body and limb movements.

Question 23

To cause serious and continuing dysfunction of the cerebellum, the cerebellar lesion usually must involve one or more of the deep cerebellar nuclei - which?

Answer 23

Dentate
Interposed
Fastigial nuclei

Question 24

What are 2 of the most important symptoms of cerebellar disease

Answer 24

Dysmetria
Ataxia

Question 25

What are the basal ganglia?

Answer 25

Another accessory motor system that functions usually not by itself but in close association with the cerebral cortex and corticospinal motor control system.

Question 26

Which anatomical regions does the ganglia comprise of?

Answer 26

Caudate nucleus, putamen, globus pallidus, substantia infra, subthalamic nucleus

Question 27

Where does the motor and sensory nerve fibres connecting the cerebral cortex and spinal cord pass through the basal ganglia?

Answer 27

Through the space that lies between the caudate nucleus and putamen: it’s called the internal capsule of the brain.