Cerebellum Flashcards
what are the three lobes of the Cerebellum?
anterior; posterior; flocculonodular lobes
the primary fissure separates?
Anterior and posterior lobes
the posterolateral fissure separates?
posterior and flocculonodular lobes
the cerebellum constitutes what percentage of the total volume of the brain? What percentage of neurons in the brain?
The Cerebellum(?little? brain) constitutes only 10% of the total volume of the brain (~ 150 gr.), but contains more than 50% of neurons of the entire brain
the cerebellum is located?
is located behind the dorsal aspect of the pons, medulla, and the fourth ventricle
the cerebellum consists of two? They are separated by the?
two hemispheres with many tightly?packed gyri; hemispheres are separated by the vermis(?worm?)
the cerebellum is composed of? Unlike the cerebrum there are no?
is composed of outer cerebellar cortex and internal white matter; Cerebellum LACKS commissural l& association fibres
similar to the cerebrum the cerebellum contains subcortical nuclei what are they?
Dentate nuclei; Interposed nuclei (emboliform nuclei + globose nuclei); Fastigial nuclei
the cerebellum is connected to the brainstem by what? What are there names?
3 paired axonal bundles called cerebellar peduncles; Superior cerebellar peduncle (axons to/from the midbrain); Middle cerebellar peduncle (axons from the pons; the biggest of the three peduncles!); Inferior cerebellar peduncle (axons to/from medulla)
all axons that enter or exit the cerebellum have to pass through?
All axons that enter or exit the cerebellum have to pass through the cerebellar peduncles
the horizontal fissure divides the cerebellum into?
two equal halves
the superior half of the cerebellum is supplied by ?
Superior half of the cerebellum is supplied by one superior cerebellar artery
the inferior half of the cerebellum is supplied by?
Inferior half of the cerebellum is supplied by two inferior cerebellar arteries
the regions of the cerebellar can be classified from a development point of view; what are the classifications?
Archicerebellum(flocculonodular lobe; oldest part); Paleocerebellum(anterior lobe, vermis &intermediate region; old part); Neocerebellum (lateral parts of the hemispheres; newest part)
the regions of the cerebellar can be classified from a functional point of view; what are the classifications?
Vestibulocerebellum(flocculonodular lobe, ?fastigial nuclei?); Spinocerebellum(anterior lobe, vermis ¶vermal region, globose &emboliform nuclei); Cerebrocerebellum(lateral cerebellar hemispheres; dentate nuclei)
the Spinocerebellum is composed of? It Regulates? It receives input from? It sends information back via the?
composed of the anterior lobe, vermis, intermediate (paravermal) hemisphere; Regulates muscle tone, posture balance; Receives input from ipsilateral spinal cord; send information back via the fastigial and interposed (globose & emboliform) nuclei to reticulospinal and rubrospinal tracts
the Vestibulocerebellum is composed of? It regulates? It receives projections form? Send information to?
Composed of the flocculonodular lobe; Regulates body balance and eye movements (÷ÿfunctions of lateral medial vestibulospinal tracts); Receives projections from vestibular nuclei; ends back information to vestibular nuclei via the fastigial nuclei
the Neocerebellum is composed of the? It coordinates? It receives afferent projections from? It projects back via?
the lateral hemispheres of the cerebellum; Coordination of fast and alternating movements; Receives afferent projections primarily from contralateral neocortex; Projects back via dentate nucleus to contralateral motor cortex (via thalamus) and red nucleus
what are the three cell layers of the cerebellar cortex?
Molecular cell layer; Purkinje cell layer; Granular cell layer
what are the two types of afferent fibbers in the cerebellar?
Mossy fibbers (terminate in the granule cell layer); Climbing fibbers (Target the purkinje cell layer;
describe the structures of the purkinje cells of the cerebellum
Purkinje cells are flat and have a 2 dimensional structure
describe the molecular layer of the cerebellar cortex
Comprised of parallel axons and dendrites; contains afferent (input) parallel fibbers of the granule cells axons; contains efferent (output) purkinje cell dendrites
describe the Purkinje cell layer of the cerebellar cortex
Comprised of thin row of large cells; made up of lots of purkinje cells; uses GABA as its primary neurotransmitter; contains afferent (input) parallel fibers of the granule cells climbing fibber from inferior olivary nucleus; efferent(output) deep cortical nuclei
describe the Granular cell layer of the cerebellar cortex
Comprised of closely packed granule cells; made up of lots of granule Cells; uses glutamate as its primary neurotransmitter; contains afferent (input) mossy fibbers; efferent(output) : Purkinje cell dendrites
the Cerebellar contains complete?
It contains complete motor and sensory representation of the body
The cerebellar compares what with what?
It compares performance with motor signals from the cerebral cortex
the cerebellar controls ?
It controls ongoing voluntary movements; detects and corrects movement errors(= adaptive adjustment)
the cerebellar is involved in?
Involved in error?based motor learning
The cerebellar controls the timing of?
Controls timing of movement/muscle action
major symptoms of cerebellar diseases are?
major symptoms of cerebellar diseases are ataxia and imbalance
