20 Cerebellum

Question 1

What is the general function of the cerebellum.

Answer 1

the cerebellum coordinates volitional movement by comparing the motor plan with movements as they occur and providing feedback to the cerebrum and brainstem nuclei for correction, including tight connection with vestibular nuclei

Question 2

What are the three vertical divisions of the cerebellum?

Answer 2

vermis (medial) medial hemisphere (middle) and lateral hemisphere (lateral)

Question 3

What are the 3 horizontal divisions of the cerebellum?

Answer 3

anterior lobe, posterior lobe and flocculonodular lobe

Question 4

Name the three arteries that supply the cerebellum and which arteries that they branch form.

Answer 4

PICA (vertebral artery) AICA (inferior basilar artery) and SCA (superior basilar artery)

Question 5

Describe the general circuit of the cerebellum.

Answer 5

input goes to purkinje cells and travels to deep nuclei which provide most of the output

Question 6

Where do mossy fibers originate?

Answer 6

There are many sources of this pathway, the largest of which is the cerebral cortex, which sends input to the cerebellum via the pontocerebellar pathway. Other contributors include the vestibular nerve and nuclei, the spinal cord, the reticular formation, and feedback from deep cerebellar nuclei. Axons enter the cerebellum via the middle and inferior cerebellar peduncles, where some branch to make contact with deep cerebellar nuclei.

Question 7

What nuclei will you find in the vermis, middle hemisphere and the lateral hemisphere respectively?

Answer 7

fastigial nucleus, interposed nucleus and dentate nucleus respectively

Question 8

By which route do outputs leave the cerebellum?

Answer 8

via the superior cerebelluar peduncles to the VA and VL thalamus and red nucleus and to multiple bainstme nuclei, including directly to the vestibular nuclei

Question 9

Where do mossy and climbing fibers enter?

Answer 9

mossy fibers enter in the middle cerebellar peduncle while climbing fibers from the inferior olive along with proprioception from the spinocerebellar tract enter the inferior cerebellar peduncle

Question 10

Which side of the brain does the cerebellum receive and send information to/from (ipsi or contra)

Answer 10

to or from the cortex, fibers cross in the brainstem before entering the cerebellum; down toward the spinal cord, fibers stay ipsilateral

Question 11

Name three general cerebellar symptoms.

Answer 11

ataxia (incoordination) dysarthria (abnormal speech due to enunciation) and vestibular systems problems

Question 12

Contrast lateral cerebral and medial cerebellar syndromes.

Answer 12

lateral leads to dysfunction of the ipsilateral limbs where medial cerebellar syndrome deals more with ataxia of the gait and trunk, both with dysarthria and vestibular symptoms

Question 13

Isolated ataxia is characteristic of what?

Answer 13

cerebellum issues whereas if there where additional symptoms it would suggest problems along cerebellar connections outside the cerebellum

Question 14

Which side of the pons would one half of the cerebellum be connected to (ipsi or contralateral)

Answer 14

ispislateral (fibers descending from the cortex cross in the midbrain and fibers ascending start and stay ipsilateral)