This document provides an overview of the cerebellum, including its anatomical structures and divisions, histological structure, connections, functions, and clinical assessment. The cerebellum is located in the hindbrain and can be divided anatomically into lobes, phylogenetically into different evolutionary sections, and functionally into areas that control balance, posture, and voluntary movement. It receives sensory inputs and its circuits coordinate motor output through connections with other brain regions. Damage can cause ataxia and other signs of impaired motor control.

1. CEREBELLUM

2. OBJECTIVES
■ Physiological Anatomy
■ Neural circuits & neuronal activity
■ Connections
■ Functions
■ Applied physiology.

3. Cerebellum.
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■ Largest part of hind brain.
■ Called “silent area.”
■ Weight- 150 gms.

4. Physiological anatomy.
■ External features .
■ Anatomical parts.
■ Anatomical divisions.
■ Phylogenetically divisions.
■ Functional divisions.
■ Histological structure.
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5. External features
■ Surfaces .
■ Folia.- transverse
folds
■ Fissures.
■ Primary
■ Horizontal
■ Posterolateral.
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6. Anatomical parts
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■ Parts of vermis.
■ Lingula
■ Central lobule
■ Culmen
■ Declive
■ Folium
■ Tuber
■ Pyramis
■ Uvula
■ Nodule.
■
■
■
■
■
■
■
■
■
■ Parts of hemisphere.
No lateral projection. Alae
Anterior quadrangular lobule
Posterior quadrangular
lobule
Superior semilunar lobule
Inferior semilunar lobule.
Biventral lobule
Tonsil
Flocculus.

7. Anatomical divisions
■ Anterior lobe.
■ Posterior lobe.
■ Flocculonodular lobe..
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8. Phylogenetically
divisions
■ Archicerebellum
■ Floculonodular lobe
■ Lingula
■ Paleocerebellum
■ Anterior lobe except – lingula
■ Posterior lobe – pyramis, uvula & paraflocculus.
■ Neocerebellum.
■ Whole posterior lobe except –pyramis & uvula.
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10. Functional divisions.
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■ Vestibulocerebellum.
■ Consists of
Floculonodular lobe
■ Vestibular connections
■ N. fastigeal – effector N.
■ Control body posture &
equilibrium.
■ Spinocerebellum.
■ Consists of
Paleocerebellum.
■ N Interpositus. – effector N.
■ Postural reflexes.
■ Corticocerebellum.
■ Central cerebellum
■ Dentate N.- effector
nucleus.
■ Smooth performance.

11. Functional divisions.
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12. Histological structure.
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■ Cerebellar cortex.
■ Molecular layer.
■ Purkinje cell layer.
■ Granule cell layer.
■ White matter.
■ Projection fibres.
■ Association fibres.
■ Commissural fibres.
■ Deep cerebellar nuclei.
■ Dentate nucleus.
■ Emboliform nucleus.
■ Globossus nucleus.
■ Fastigeal nucleus.

13. Histological structure.
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14. Cerebellar cortex.
■ Molecular layer.
■ Stellate cells
■ Basket cells.
■ Purkinje cell layer.
■ Granule cell layer.
■ Granule cells
■ Golgi cells.
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15. Cerebellar cortex.
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16. Sensory inputs.
■ Climbing fibres
■ Inferior olivary nucleus
■ Cerebellum.
( purkinje cells)
■ Mossy fibres.
■ Spino, vestibulo,
reticulo, cuneo &
corticoponto
■ Cerebellum
(Glomerulus)
Olivocerebellar tract.
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17. Sensory inputs.
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20. White matter.
■ Projection fibres. ■ Association fibres.
■ Commissural fibres.
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21. Deep Cerebellar Nuclei.
■ Dentate nucleus.
■ Emboliform
nucleus.
■ Globossus nucleus.
■ Fastigeal nucleus.
Near roof of IV
ventricle.
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23. Neural circuits & neuronal
activity.
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■ Afferents of cerebellar cortex.
■ Climbing Fibres.
■ Mossy Fibres.
■ Neuronal activity of deep cerebellar circuits
■ Feed forward inhibition of purkinje cells.
■ Feed forward inhibition of Granule cells.
■ Feed back inhibition of Granule cells.
■ The reverberating circuits.
■ Neuronal activity of deep cerebellar nuclei.

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26. Afferents of cerebellar cortex.
■ Climbing Fibres. ■ Mossy Fibres.
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27. Neuronal activity of deep
cerebellar circuits
■ Feed forward inhibition of Purkinje cells.
■ Mossy fibres Granule cells
■ Purkinje cells. Basket cells.
■Feed forward inhibition of Granule cells. Mossy
fibres Granule cells.
Golgi cells
■ Feed back inhibition of Granule cells.
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28. Neuronal activity of deep
cerebellar neuclei.
Cerebral cortex
Thalamus
motor
pathway.
spinal cord.
brainstem nuclei.
Deep cerebellar nuclei.
Climbing fibres, mossy fibres.
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29. Connections of cerebellum.
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■ Cerebellar Peduncles..
■ Inferior
■ Afferents
▪ Dorsospinocerebellar.
▪ External arcuate
fibres.
▪ Vestibulocerebellar
tract.
▪ Oliocerebellar tract.
▪ Reticulocerebellar
tract.
■ Middle.
■ Afferents. – cerebro-
pontine – cerebellar.
■ Superior
■
■ Afferent –
▪ Tectocerebellar
▪ Ventral
spinocerebellar
Efferent –
▪ Dentorubral
▪ Dentothalamic
▪ Mid-brain.

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31. Afferent connections
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■ Dorsal spinocerebellar tract. (external)
■ Ventral spinocerebellar tract. (Internal)
■ Cuneocerebellar tract.
From accessory cuneate N.
■ Olivocerebellar tract.
From brainstem, SC, cortex

32. Afferent connections
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■ Cortico-ponto-cerebellar tract.
■ Tectocerebellar tract.
From superior colliculi (visual impulses)&
inferior colliculi (auditory impulses)of
tectum of mid brain.
■ Vestibulocerebellar tract. (position &
movement of head)
■ Rubrocerebellar tract. ( from motor cortex )
■ Reticulocerebellar tract.

33. Afferent connections
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34. Localization of sensory
impulses to cerebellum.
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35. Efferents connections.
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■ Dento-rubro-thalamo-
cortical pathway.
■ Cerebello-thalamic-
cortical pathway.
■ Cerebelloreticular
pathway.
■ Cerebellovestibular
fibres.
■ Cerebello-olivary
fibres.
■ Oculomotor nerve &
tectum.

36. Efferent connections.
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38. Functions of cerebellum.
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■ Control of body posture & equilibrium.
■ Control of muscle tone & stretch reflex.
■ Control of voluntary movements.

39. Control of body posture &
equilibrium.
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40. Control of muscle tone &
stretch reflex.
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41. Control of voluntary movements.
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42. Mechanism of action.
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■ Comparator function.
■ Damping action.
■ Timing & programming the movements.
■ Control of ballistic movements.
■ Servomechanism.

43. Comparator function.
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44. Other functions of cerebellum.
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■ Autonomic system (through Hypothalamus &
reticular formation.)
■ Ascending sensory pathway. (through
reticular formation & thalamus)
■ Eyeball movements. ( through vestibular
nuclei)

45. Cerebellar lesions.
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■ Common causes.
■ Signs of cerebellar dysfunction.
■ Tests .

46. Common causes.
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■ Vascular occlusions (thrombosis)
■ Tumor
■ Injuries.

47. Signs of cerebellar dysfunction.
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■ Tone & posture disturbance
■ Atonia or hypotonia
■ Attitude changes.
■ Rotation of face to opposite side
■ Lowering of shoulder.
■ Outward rotation & abduction of leg.
■ Deviation movements.
■ Effect on deep reflexes. (weak & pendular)

48. Signs of cerebellar dysfunction.
s
■ Equilibrium disturbance. (drunken gait)
■ Movements disturbance.
■ Ataxia
■ Intention tremor
■ Nystagmus.
■ Dysarthria.
■ Astasia.
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49. Clinical tests of cerebellar
dysfunction.
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■ Upper limb
■ Finger nose test
■ Diadokokinesia.
■ Rebound phenomenon.
■ Past pointing.
■ Lower limb.
■ Rombergs test.
■ Tandem gait.

50. Tests .
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51. Thank
You