Cerebellum

Question 1

Paleocerebellum or Spinocerebellum:
What are the parts?
What does it control?
What is its main input?
What are the associated nuclei?

Answer 1

Vermis and adjacent cortices of anterior and posterior lobes (intermediate zone)
Adjusts ongoing movements and regulates muscle tone
Spinocerebellar tracts
Emboliform and globose nuclei (interposed nuclei)

Question 2

Pontocerebellum or Neocerebellum:
What are the parts?
What does it control?
What is its main input?
What is the associated nucleus?

Answer 2

Most of cerebellar cortex (lateral zone)
Coordinates planning of movement
Sensory and motor cortices
Dentate nucleus

Question 3

What are the layers of the cerebellar cortex?
What cells (cell bodies) are found in each layer?

Answer 3

Molecular - stellate and basket cells
Purkinje - Purkinje cells
Granular - granule and Golgi

Question 4

What is the function of granule cells of the cerebellum?

What fibers do they make up to some of these cells?

Answer 4

Excitatory to basket, stellate, Golgi and Purkinje cells

Parallel fibers

Question 5

What is the function of basket cells in the cerebellum?

Answer 5

Inhibitory on the body of Purkinje cells

Question 6

What is the function of stellate cells in the cerebellum?

Answer 6

Inhibitory on the dendrites of Purkinje cells

Question 7

What is the function of Golgi cells in the cerebellum?

Answer 7

Inhibitory on mossy fibers in granular layer

Question 8

What is the function of Purkinje cells in the cerebellum?

What neurotransmitter do they use?

Answer 8

Inhibitory on deep cerebellar nuclei (DEGF)

GABA

Question 9

Mossy Fibers (of the Cerebellum):
Where do their axons terminate?
What kind of synapse do they form?
What information do these fibers provide?

Answer 9

Dendrites of granular cells
Excitatory
Qualities of movements - muscles involved, direction, speed, tone

Question 10

Climbing Fibers:
Where do their axons originate?
Where do their axons terminate?
What kind of synapse do they form?
What information do these fibers provide?

Answer 10

Inferior olivary nucleus
Dendrites of Purkinje cells
Excitatory
Errors in execution of movements

Question 11

What are the pathways ascending to the cerebellum?

What kind of fibers are these pathways?

Answer 11

Anterior spinocerebellar
Posterior spinocerebellar
Cuneocerebellar
All mossy

Question 12

Anterior Spinocerebellar Pathway:

What specific information does it provide?

Answer 12

Input from Golgi tendon organs, spinal interneurons, cutaneous receptors, fibers of descending tracts of distal part of lower extremities

Question 13

Anterior Spinocerebellar Pathway:
What is the location of first order cell bodies?
What is the path of their axons?

Answer 13

DRG

Follow fasciculus gracilis for short while

Question 14

Anterior Spinocerebellar Pathway:
What is the location of second order cell bodies?
What is the path of their axons?

Answer 14

Spinal border cells in lumber regions of anterior horn in lamina VII
Cross at AWC, ascend on anterior spinocerebellar tract, cross again in brainstem, enter cerebellum through SCP

Question 15

Posterior Spinocerebellar Pathway:

What specific information does it provide?

Answer 15

Golgi tendon organs and muscle spindles from proximal part of lower extremities

Question 16

Posterior Spinocerebellar Pathway:
What is the location of first order cell bodies?
What is the path of their axons?

Answer 16

DRG

Follow fasciculus gracilis for short while

Question 17

Posterior Spinocerebellar Pathway:
What is the location of second order cell bodies?
What is the path of their axons?

Answer 17

Clarke’s column (nucleus)

Ascend on dorsal spinocerebellar tract, enter cerebellum through ICP

Question 18

Cuneocerebellar Pathway:

What specific information does it provide?

Answer 18

Golgi tendon organs and muscles spindles from upper extremities

Question 19

Cuneocerebellar Pathway:
What is the location of first order cell bodies?
What is the path of their axons?

Answer 19

DRG

Ascend via fasciculus cuneatus

Question 20

Cuneocerebellar Pathway:
What is the location of second order cell bodies?
What is the path of their axons?

Answer 20

Lateral (external) cuneate nucleus

Ascend on cuneocerebellar tract, enter cerebellum through ICP

Question 21

What is the general plan of cerebellar pathways?

Answer 21

Corollary motor discharge
Sensory feedback
Modulation of output

Question 22

What are the motor monitoring pathways?

What is a general rule regarding these pathways?

Answer 22

Paleocerebellar
Pontocerebellar
Vestibulocerebellar
There is considerable overlap

Question 23

Paleocerebellar Pathway:
What is the path of neurons for corollary motor discharge?
What is the path of neurons for sensory feedback?
What is the path of neurons for modulation of output?

Answer 23

CMD - red nucleus, inferior olivary nucleus, ICP
SF - muscle spindles and joint receptors, cerebellar tract, ICP
MO - Globose and emboliform nuclei, SCP, red nucleus, rubrospinal tract or other motor pathway, muscle

Question 24

Pontocerebellar Pathway:
What is the path of neurons for corollary motor discharge?
What is the path of neurons for sensory feedback?
What is the path of neurons for modulation of output?

Answer 24

CMD - motor cortex, corticospinal tract, MCP
SF - sensory cortex, MCP
MO - dentate nucleus, SCP, VL of thalamus, motor cortex, corticospinal tract, muscle

Question 25

Vestibulocerebellar Pathway: What is the path of neurons for corollary motor discharge? What is the path of neurons for sensory feedback? What is the path of neurons for modulation of output?

Answer 25

CMD - vestibular nucleus, ICP SF - semicircular canals, ICP MO - fastigial nucleus, ICP, vestibular nucleus, motor pathway, muscle

Question 26

Truncal Ataxia: What is the cause? How will a patient present? What tests can be performed and what are positive results?

Answer 26

Lesion to vermis or flocculonodular lobe Loss of equilibrium, wide stance, problems balancing, veering to one side, unsteady gait Tandem gait test - patient falls or deviates to one side while walking a line Romberg test - proprioception in dorsal columns, positive if swaying with eyes closed

Question 27

``` Appendicular Ataxia: What is the cause? What is the effect? How will a patient present? What test can be performed and what are positive results? ```

Answer 27

Lesion to cerebellar hemispheres or lateral zone Lateral motor systems, movement of extremities, skilled and fine voluntary or planned movements, errors in force, direction, amplitude and speed Dysdiadochokinesia, pronation and supination problems, loss of muscle tone, dysmetria Finger-nose-finger test - positive when wavering or missing target