cerebellum Flashcards
what are climbing fibers?
the terminal branches of the olivocerebellar tracts
one climbing fiber makes contact with how many purkinje cells?
1-10 loui say 7
what are mossy fibers?
terminal branches of all other cerebellar afferent tracts except olivocerebellar
what are the two main lines of input to the cerebellar cortex?
climbing and mossy fibers
note: they excite purkinje cells
what are the inhibitory interneurons of the cerebellar cortex?
stellate, basket and golgi cells
purkinje cells form the center of a functional unit of the cerebellar cortex. T or F.
T
what are the cerebellar peduncles?
numerous efferents and afferents leaving and entering the cerebellum are bundled up to make the peduncles
they connect the cerebellum to the other parts of the cns
what are the cerebellar afferent fibers from the cerebral cortex?
- corticopontocerebellar pathway
- cerebro-olivocerebellar pathway
- cerebroreticulocerebellar pathway
corticopontocerebellar pathway?
Fibers from frontal, parietal, temporal and occipital lobes terminate on the pontine nuclei which give rise to transverse pontine fibers. These fibers cross the midline and enter the opposite cerebellar hemisphere as the middle cerebellar peduncle.
cerebro-olivocerebellar pathway?
Fibers arise from frontal, parietal, temporal and occipital lobes and terminate bilaterally on the inferior olivary nuclei in medulla which give rise to fibers that cross the midline and enter the opposite cerebellar hemisphere thru the inferior cerebellar peduncle. These fibers terminate as climbing fibers
cerebroreticulocerebellar pathway?
These fibers arise from sensorimotor areas then descend to terminate in the reticular formation on the same side and on the opposite side in the pons and medulla which give rise to the reticulocerebellar fibers that enter the cerebellar hemisphere on the same side thru the inferior and middle cerebellar peduncles.
What are the cerebellar afferents from the spinal cord?
- anterior spinocerebellar
- posterior spinocerebellar
- cuneocerebellar
The entire output of the cerebellar cortex is through the axons of which cells?
Purkinje cells
The efferent fibers from the cerebellum connect with which structures?
Red nucleus
Thalamus
Vestibular complex
Reticular formation
Globose-emboliform-rubral pathway?
Axons of globose and emboliform nuclei travel thru the superior cerebellar peduncles then they cross the midline at the decussation of superior cerebellar peduncles. The fibers end by synapsing on the contralateral red nucleus giving rise to the rubrospinal tract. So they double cross
Dentothalamic pathway?
The axons from the dentate nucleus travels through the superior cerebellar peduncle and cross the midline in the decussation of superior cerebellar peduncle. The fibers end by synapsing in the contralateral ventrolateral nucleus of the thalamus
Note: those axons of the thalamic neurons terminate in the primary motor area
Fastigial vestibular pathway?
Axons of the fastigial nucleus travel thru inferior cerebellar peduncle n terminate on the neurons of lateral vestibular nucleus in medulla
Note: neurons of the lateral vestibular nucleus form the vestibulospinal tract
Fastigial reticular pathway?
Axons from Fastigial nucleus travel thru the inferior peduncle and end by synapsing on the reticular formation.
Note: axons of these neurons influence reticulospinal tract
Two basic defects of cerebellar disease are?
Hypotonia and loss of influence of the cerebellum on the activities of the cerebral cortex
What is the function of the cerebellum?
Coordinates precise movements by continually comparing output of the motor area of the cerebral cortex with the proprioception info received from the site of muscle action n makes necessary adjustments
Cerebellar afferent fibers from the vestibular nerve?
Vestibular nerve receives info from the inner ear concerning motion which then send afferent fibers to the cerebellum thru the inferior cerebellar peduncle on the same side. All afferent fibers from the inner ear terminate as mossy fibers in the flocculonodular lobe
Fibers from dentate, emboliform and globose nuclei leave cerebellum through?
Superior cerebellar peduncle
Fibers from fastigial nucleus leave through?
Inferior cerebellar peduncle
Afferent fibers enter the cerebellum mainly thru?
Inferior and middle cerebellar peduncles
What are the layers of the cerebellar cortex?
Molecular (external)
Middle (purkinje)
Internal (granular)
What are the three functional areas of the cerebellar cortex?
Cortex of vermis- influence long axis of body
Intermediate zone- control muscles of distal parts of limbs
Lateral zone- planning sequential movements of entire body
Climbing and mossy fibers are inhibitory. T or F.
False.
Mossy fibers end on granular cells. T or F.
True
Granule cells are excitatory. T or F.
T
Deep cerebellar nuclei receive afferent information from which two sources?
Inhibitory axons from purkinje
Excitatory axons from climbing and mossy fibers
What are the functional divisions of the cerebellum?
Vestibulocerebellum
Spinocerebellum
Pontocerebellum
All afferent fibers from inner ear terminate as mossy fibers in flocculonodular lobe. T or F.
True
Note: from vestibular nerve