Cerebellum Flashcards
What separates the anterior and posterior lobes of the cerebellum?
The primary fissure
Where are the cerebellar tonsils located?
Lie next to the lower medulla above the foramen magnum
Describe the histology of the three layers of the cerebellum
Outer layer: pale with mostly axons and few cells
Middle layer: single row of Purkinge cells
Inner layer: thick granule layer
What connections are there from the superior cerebellar peduncle?
Only outputs from the cerebellum to the brain and rest of the body
What connections are there from the middle cerebellar peduncle?
Inputs from the contralateral cortex and cranial nerves via the pons
What connections are there from the inferior cerebellar peduncle?
Input from the spinal cord via spinocerebellar tracts
How do the spinocerebellar tracts enter the cerebellum?
Via the inferior cerebellar peduncle
Describe the path of the dorsal (posterior) spinocerebellar tract
Travels from the ipsilateral side up the brainstem and into the inferior cerebellar peduncle on the same side (entirely IPSILATERAL)
Describe the path of the ventral (anterior) spinocerebellar tract
Carries information from the contralateral side of the body
Describe the path of the anterior/ventral spinothalamic tract
Decussates at the level of spinal cord entry but then recrosses in the brainstem and therefore enters the brainstem ipsilaterally to origin
What is the purpose of the dorsal spinocerebellar tract?
Carries information from proprioceptors (joints, muscle spindles etc)
What is the purpose of the ventral spinocerebellar tract?
Carries information about the state of reflexes and neurones in the spinal cord
What are the names of the deep cerebellar nuclei?
Fastigial nucleus, globose nucleus, emboli form nucleus and dentate nucleus
What is the general function of the cerebellum?
Involved in aiding the motor cortex in producing accurate and smooth movement
What are the consequences of cerebellar damage?
Clumsiness, abnormal fatigue and instability of movement; extraocular eye muscles are particularly affected.
What are the three main functional zones of the cerebellum?
Vestibulocerebellum, spinocerebellum and cerebrocerebellum
What makes up the vestibulocerebellum?
The flocculonodular lobe
What it is the function of the vestibulocerebellum?
To coordinate head and eye movements and control the balance of the head via the vestibulospinal tracts
What makes up the spinocerebellum?
Anterior lobe and the vermis (with fastigial and interposed deep nuclei)
What is the function of the spinocerebellum?
Controls locomotion and limb coordination via lateral vertibulospinal and reticulospinal tracts
What makes up the cerebrocerebellum?
Posterior lobe of cerebellum and dentate nuclei; input from cerebral cortex via middle cerebral peduncle and output to the central thalamus via the superior cerebral peduncle
What is the function of the cerebrocerebellum?
Involved in coordinating movement e.g.speech, voluntary movement of hands and arms and hand-eye coordination
What are three three main cerebellar syndromes?
Floculonodular syndrome, anterior lobe syndrome and neocerebellar syndrome
What is a common cause of flocculonodular syndrome?
Medulloblastoma - usually originating the floor of the 4th ventricle . Most common in young children
