cerebellum Flashcards
T/F? there is more neurons in cortex of cerebellum than the cerebrum?
True
the white matter and grey matter of the cerebellum is called what when observed in cross section
arbor vitae - tree of life
the outputs of the cerebellum are called and are located where?
they are called dentate, emiliform and globose (interposed collectively), fastigal, and the vestibular nuclei and are relayed from the cerebellum to these nuclei via the superior cerebellar peduncle
Dont Eat Greasy Foods Veryoften - mneumonic
they are all located in the cerebellar white matter
dentate is the largest nucleus, and collects information from the lateral hemispheres
interposed collects information from the intermediate lobes
the fatigal collects infromation from the vermis
and the vestibular collects information from the flocculi and infrior vermis
from here the information travels back to the thalamus and back to the motor cortex
name all the anatomical regions and functional regions of the cerebellum
anatomical - anterior and posterior lobes of the cerebellum, the most inferior portions are called the cerebellar tonsils and are privy to herniation through the foramen magnum when mass effect occurs
the functional regions are:
the vermis, which is medial
bilateral to the vermis are the intermediate hemispheres
them the lateral hemispheres are lateral to the the intermediate hemispheres
the flocullonodular lobe is medial and inferior to anterior lobe, they are in close association with the cerebellar peduncles
the vermis controls the coordination of the proximal limb and trunk muscles
the intermediate lobes control the distal musculature coordination
the lateral lobes control motor planning for the extremeties
the floculonodular lobes control balance and the vestibulo-ocular reflexes (they send information to the medial longitudinal fasiculus)
the cerebral peduncles
the superior peduncles (AKA brachium conjunctivum) carry cerebellar outputs to deep cerebellar nuclei
the middle (AKA brachium pontis) and inferior (AKA restiform body) cerebellar peduncles carry inputs into the cerebellum
what are the names of the three cortical layers of the cerebellum going to lateral to medial
molecular layer
purkinge layer
granule (innermost)
what are the main inputs of excitatory cells of the cerebellum
granule cells which comprise the molecular layer by longitudinal arrays of parralel fibres
stellate cells, basket cells, golgi cells are all
interneuron cells of the cerebellum and are all inhibitory by using the chemical mediator GABA
what are the names of the input fibres that relay information into the cerebellar cortex and where do these inputs originate from?
mossy and climbing fibres
mossy fibres originate from a range of locations such as the pons and collect as glomeruli within the granule layer to activate granule cells
whereas climbing fibres originate from the inferior olive (function of which is poorly understood) and directly signal to the parallel fibres in the molecular layer
what do mossy fibres do?
they activate granule cells which activate parrallel fibres within the molecular layer, this activates purkinje cells (cell for all cerebellar output) which relays information to the deep cerebellar nuclei
purkinje cells are…
within the purkinje layer and the cell type that relays all cerebellar input to the deep cerebellar nuclei, they are generally inhibitory using the NT GABA, they are one of the largest neurons known
climbing fibres….
directly activate purkinje cells and inhibit parallel fibres leading to activation of the deep cerebellar nuclei
signs of cerebellar disease include
ataxia "drunken based gait" dysdiadochokinesia intention tremour scanning speech - dysarthria nystagmus
lesions of the cerebellum are usually
ipsilateral to the deficit as there is double crossing from information from the spinal cord to the cerebellum
