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35 Cards in this Set
- Front
- Back
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What is in the midline of the cerebellum? |
Folia 'oak leaves' |
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What are the 3 layers of the cerebellum? |
Molecular layer - pale, few cells Middle layer - single row of purkinje cells Inner/granular layer - thick: vast numbers of granule cells |
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What features characterise purkinje cells? |
Have large dendritic trees flattened into 1 plane. Lie stacked parallel to each other across the line of the folia. |
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How many folia are there? What divides the anterior and posterior lobes of the cerebellum? |
10 main folia. The primary fissure |
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What is the nodulus and its anatomical relevance? |
Median part of the floconodular lobe on the ventral surface of the cerebellum. Forms the roof of the 4th ventricle. |
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Where does the cerebellar vermis lie? |
Along the midline |
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What branches form the cerebellar blood supply? |
Vertebral and basilar arteries. Superior to inferior: PCerebellarA SCA Pontine branches basilar AICA BIFURCATION VERTEBRAL PICA |
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Give some features of the PICA. |
Largest branch of the VERTEBRAL artery. Arises on the caudal end of the medulla on each side. |
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What does the PICA supply? |
Posterior part of cerebellar hemisphere. Inferior vermis Central nuclei cerebellum Choroid plexus of 4th ventricle Part of medulla |
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What are the main inputs and outputs to the cerebellum? |
Via cerebellar peduncles: Inferior - input fibres from SC via dorsal and ventral spinocerebellar tracts Middle (largest) - input fibres from forebrain and cranial nerves via pons Superior - output fibres to brainstem nuclei |
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What is the function of the ventral spinocerebellar tract (as opposed to the dorsal - main one)? |
DOUBLE CROSSER Carries info about state of interneurones and spinal reflexes. Propriocetive info to the cerebellum - via superior peduncle |
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How are inputs and outputs received in the cerebellum? |
Via deep cerebellar nuclei, lie in the white matter below the cortex |
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Which tract synapses onto Clarke's nucleus? |
Dorsal SC |
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What are the 3 deep cerebellar nuclei? |
Lateral to medial: Dentate, Globose/emboliform (interposed), fastigial |
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What is the role of the floconodular lobe? |
Links to lateral vestibular nuclei of the pons. This nucleus does the same as the deep nuclei do for the other hemispheres of the cerebellum. |
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What are the 3 functional zones in the cerebellum? |
Vestibulocerebellar - comprises floconodular lobe Spinocerebellar - comprises anterior lobe and vermis Cerebrocerebellar - comprises posterior lobe (cerebellar hemisphere) |
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Describe the general principle of cerebellar action. |
The deep nucleus is the ‘central
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What is the major input to, cerebellar cortical region of, and deep nucleus of the vestibulocerebellum? |
Input - otolioth organs Cerebellar cortical region - F/N lobe Deep nucleus - vestibular nuclei |
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What is the major input to, cerebellar cortical region of, and deep nucleus of the spinocerebellum? |
Input - SC Cerebellar cortical region - Vermis + anterior lobe Deep nuclei - Vermis -> fastigial nucleus, anterior -> Interposed nucleus |
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What is the major input to, cerebellar cortical region of, and deep nucleus of the cerebrocerebellum? |
Input - CC Cerebellar cortical region - lateral hemisphere Deep nucleus - dentate nucleus |
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What is the function of the vestibulo cerebellum? |
Co-ordinates head and eye movements to ensure the stability of gaze. It also controls balance
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What is the main input and output of the vestibulocerebellum? |
Main input - vestibular apparatus and extraocular muscles + muscles from head and neck Main output - Medial longitudinal fasiculus + its caudal extension medial vestibulospinal tract to neck and eye muscles. |
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Where are the motor programs for vestibulocerebellar tasks stored? |
F/N lobe |
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What is the function of the spinocerebellum? |
Controls locomotion and limb coordination sends motor commands down lateral vestibulospinal + reticulospinal tracts |
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What is the function of the cerebrocerebellum? |
Co-ordinates movement initiated by the motor cortex: speech, voluntary movements of hands and arms + hand eye coord. |
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What is floconodular syndrome? |
Poor balance and disordered eye movements. There may be nystagmus, ocular dysmetria and poor visual pursuit (tracking). Unsteady and unable to stand Romberg's test with eyes open/closed, unable to perform tandem gate. Severe midline disturbance - truncal ataxia: can't sit on bed without steadying. Some have titubation - bobbing of head and trunk. |
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What aetiology is F/N syndrome most common? |
Medulloblastoma in 4th ventricle wall. Tendency to fall to side of the lesion. |
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Describe medulloblastoma. |
Most common CNS tumour in children, 15-20% brain tumours children. Family of primitive neuroectodermal tumours (PNET) Most diagnosed before 5. 80-90% w/o dissemination can be cured, >50% children with MDB can be free of disease after 5 yrs. |
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What is anterior lobe syndrome? SEEN IN ALCOHOLICS/B VIT DEFICIENCY. |
Correlated with damage to spinocerebellum. It is characterized by Ataxia: gait Hypotonia: generalised muscle weakness and fatigue Dysdiadochokinesis: irregular performance of rapidly altering movements Depressed reflexes/pendular.
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What is neocerebellar syndrome? SEEN IN STROKE TUMOUR TRAMA DEGENERATIVE DISEASE |
Loss hand eye coordination. Dysmetria (inaccurate reaching w/ intention tremor) Dysdiadochokinesis Intention tremor: finger to nose/heel to knee test anterior lobe. Slurred speech: loss coordination of muscles involved in speech production Loss cognitive eye movements + motor skill Deficits selective attention and perception |
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What is seen in cerebellar stroke? |
1. Intense headache, vertigo, nausea, vomiting 2. Eye changes - one eye, contribute vertigo, nystagmus ptosis miosis. 3. Dysarthria + dysphagia (weakness of mouth face respiratory pharyngeal oesoph muscles) 4. Ataxia - wide wobbly gait 5. Arm weakness + incoordination - clumsiness weakness 1 arm. Test - raise both arms, is one lower/ trembling? |
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What is the mnemonic for cerebellar stroke? |
A Happy Squirrel Now Dancing In TIme: Ataxia, hypotonia, slurred speech, nystagmus, diplopia intention Tremor. |
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How are motor commands to neck and eye muscles sent? |
To MLF and medial vestibulospinal tract (caudal extension to SC) Motor commands to legs via lateral vestibulospinal tract |
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How are motor commands to neck and eye muscles sent? |
To MLF and medial vestibulospinal tract (caudal extension to SC) Motor commands to legs via lateral vestibulospinal tract |
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What is the function of the vestibular nuclei? |
Info from vestibular apparatus about movements of head is sent to the vestibular nuclei. This info combined with info from extra-ocular eye muscles and from muscles in neck |
