Stephens Cerebellar Lecture Flashcards
What is the broad function of the cerebellum
Process unconscious proprioceptive and tactile info to impact muscle movement and create smooth and ordered sequences of contractions
What is the Fastigial nucleus and where is it found?
Found within the Corpus Medullares, the core of white matter in the cerebellum. It is most medial nucleus of the four in this area and it has vestibular connections.
What is the Globose Nucleus?
Found within the Corpus Medullares, the core of white matter in the cerebellum. It is divided into medial and lateral parts. The Cerebellovestibular efferent is from the medial globose and projects to the vestibular system along with the fastigial nuclei. Efferents from the lateral globose course with fibers from eboliform and dentate.
What is Emboliform nucleus?
Found within the Corpus Medullares, the core of white matter in the cerebellum. Small worm like nucleus that sends efferents throug hsuperior cereballar peduncle with fibers from dentate nucleus
What is dentate nucleus?
Found within the Corpus Medullares, the core of white matter in the cerebellum. Gives rise to majority of efferents from cerebellum. Projects to the red nucleus and ventral lateral nucleus of thalamas, tegmentum of brainstem and the reticular formation. Aside from those the dentate nuc is most responsible for planning and executing fine movement
What does the Dorsal Spinocerebellar tract do?
- Unconscious and precise proprioceptive information from the lower half of the body and LE to the cerebellum
- Comes from th enucleus dorsalis and courses through ipsilateral inferior cerebellar peduncle
- Terminates in anteerior vermis of cerebellum
What does the Direct Arcuate Fibers aka Cuneocerebellar Tract do?
- Unconscious precise propriocceptive info from the upper half of body and UE
- Originates in the accessory cuneate nucleus and terminates in the vermis
- (Opposite of DSCT but terminates same)
What does the trigeminocereballar tract do?
- General proprioceptive and exteroceptive info from the head
- Subnuclei rostralis and interpolaris of descending nucleus of trigeminal project to anterior vermis as trigeminocerebllar fibers
Arcuocerebellar Fibers ?
- Arcuate nuclei of upper medullar recieves fibers from ipsilateral cerebral cortex and to the contralateral cerebellar hemisphere via arcuate fibers
Reticulocerebellar fibers?
- Conveys general sensory modalities to cerebellum
- Reticulocerebellar fibers come from the lateral reticular nuclei and project bilaterally to the cerebellar hemispheres
Olivocerebellar fibers
- Originates in inferior olivalry nucleus and terminates as clilmbing fibers in contralateral cerebellar hemisphere
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What is the critical link between extrapyramidal system and the cerebellum?
Central Tegmental Fasciculus
What are the six sensory pathways in the inferior cerebellar peduncle?
- Dorsal Spibnocerebellar (DCST)
- Direct Arcuate Fibers
- Trigeminocerebellar Tract
- Arcuocerebellar fibers
- Reticulocerebellar fibers
- Olivocerebellar fibers
DDT Always Ruins Olives
What are th ethree pathways in the superior cerebellar peduncle?
- Ventral Spinocerebellar Tract (VSCT)
- Trigeminocerebellar Tract
- Tectocereballar
What is the VSCT?
- Unconscious general proprioceptive infro from the lumbosacral levels to cerebellum
- It comes from dorsal horn decussates in AWC and ascends in the lateral funiculus
- Passes throug hsuperior cerebellar peduncle and terminates in anterior vermis of cerebellum
What is the Trigeminocerebellar tract?
- Precise tactile and proprioceptive info from the head to cerebellum
- From main sensory nucleus of V and proects to anterior vermis of cerebellum via sup cerebellar pedunclel
Overall what is the Ventral Spinocerebellar tract responsible for?
- Gross postural adjustments and overall proprioception of the lower limb
- Primary axons from lumbosacral levels of spinal cord and the secondary axons decussate in AWC and ascend in the contralateral central spinocerbellar tract
What do the Tectocerebellar fibers do?
- Conveys visual and auditory sensations
- Originates in the inferior and superior colliculi
All information entering the cerebellar cortex converges upon what cells
Purkinjie cells- their axons are the only efferent fibers from the cerebellar cortex and most of them terminate in the deep cerebellar nuclei
What is the difference between climbing and mossy fibers?
- Climbing fibers are direct afferents to the cerebellar cortex from the olivocerebellar fibers.
- Climbing fibers are excitatory to the purkinjie cells
- Mossy fibers come from spinocerebellar tracts and are afferent fibers to the cerebellar cortex.
- Mossy fibers are also excitatory
What are possible results from a lesion in the cerebellum?
- Ataxia
- Dysdiadochokinesia
- Dysmetria
- Intention tremor
- Decompositon of movoement
- Slurred spee h
- Hypotonia and Hyporeflexia
- Asthenia
- Nystagmus
Cerebellar cortical influences converge on which of the following?
- Deep cerebellar nuclei
- Granule cells
- Parallel fibers
- Purkinjie 4 ecells
- Purkinjie cells
A unilateral lesion of the right cerebellar lobe would result in ?
- Bilateral cerebellar deficits
- Contralateral cerebellar deficits
- Ipsilateral cerebellar deficits
- Ipsilateral
Olivocerebellar fibers have a stong influence on what fibers?
- Cerebellar glomerulus
- Deep cerebellar nuclei
- Granule cells
- Parallel fibers
- Purkinjie cells
- Purkinjie cells
