Cerebellum ppt

cerebellum powerpoint

1. DR NILESH KATE
MBBS,MD
ASSOCIATE PROF
ESIC MEDICAL COLLEGE, GULBARGA.
DEPT. OF PHYSIOLOGY
CEREBELLUM

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

3. Cerebellum.
Largest part of hind brain.
Called “silent area.”
Weight- 150 gms.
Friday, January 16, 2015

4. Physiological anatomy.
External features .
Anatomical parts.
Anatomical divisions.
Phylogenetically divisions.
Functional divisions.
Histological structure.
Friday, January 16, 2015

5. External features
Surfaces .
Folia.- transverse
folds
Fissures.
Primary
Horizontal
Posterolateral.
Friday, January 16, 2015

6. Anatomical parts
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.
Friday, January 16, 2015

7. Anatomical divisions
Anterior lobe.
Posterior lobe.
Flocculonodular lobe..
Friday, January 16, 2015

8. Phylogenetically
divisions
Archicerebellum
Floculonodular lobe
Lingula
Paleocerebellum
Anterior lobe except – lingula
Posterior lobe – pyramis, uvula & paraflocculus.
Neocerebellum.
Whole posterior lobe except –pyramis & uvula.
Friday, January 16, 2015

9. Friday, January 16, 2015

10. Functional divisions.
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.
Friday, January 16, 2015

11. Functional divisions.
Friday, January 16, 2015

12. Histological structure.
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.
Friday, January 16, 2015

13. Histological structure.
Friday, January 16, 2015

14. Cerebellar cortex.
Molecular layer.
Stellate cells
Basket cells.
Purkinje cell layer.
Granule cell layer.
Granule cells
Golgi cells.
Friday, January 16, 2015

15. Cerebellar cortex.
Friday, January 16, 2015

16. Sensory inputs.
Climbing fibres
Inferior olivary nucleus
Cerebellum.
( purkinje cells)
Mossy fibres.
Spino, vestibulo,
reticulo, cuneo &
corticoponto
Cerebellum
(Glomerulus)
Friday, January 16, 2015
Olivocerebellar tract.

17. Sensory inputs.
Friday, January 16, 2015

18. Friday, January 16, 2015

19. Friday, January 16, 2015

20. White matter.
Projection fibres. Association fibres.
Commissural fibres.
Friday, January 16, 2015

21. Deep Cerebellar Nuclei.
Dentate nucleus.
Emboliform
nucleus.
Globossus nucleus.
Fastigeal nucleus.
Near roof of IV
ventricle.
Friday, January 16, 2015

22. Friday, January 16, 2015

23. Neural circuits & neuronal
activity.
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.
Friday, January 16, 2015

24. Friday, January 16, 2015

25. Friday, January 16, 2015

26. Afferents of cerebellar cortex.
Climbing Fibres. Mossy Fibres.
Friday, January 16, 2015

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.
Friday, January 16, 2015

28. Neuronal activity of deep
cerebellar neuclei.
Cerebral cortex motor
pathway.
spinal cord.
Thalamus brainstem nuclei.
Deep cerebellar nuclei.
Climbing fibres, mossy fibres.
Friday, January 16, 2015

29. Connections of cerebellum.
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.
Friday, January 16, 2015

30. Friday, January 16, 2015

31. Afferent connections
Dorsal spinocerebellar tract. (external)
Ventral spinocerebellar tract. (Internal)
Cuneocerebellar tract.
From accessory cuneate N.
Olivocerebellar tract.
From brainstem, SC, cortex
Friday, January 16, 2015

32. Afferent connections
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.
Friday, January 16, 2015

33. Afferent connections
Friday, January 16, 2015

34. Localization of sensory
impulses to cerebellum.
Friday, January 16, 2015

35. Efferents connections.
Dento-rubro-thalamo-
cortical pathway.
Cerebello-thalamic-
cortical pathway.
Cerebelloreticular
pathway.
Cerebellovestibular
fibres.
Cerebello-olivary
fibres.
Oculomotor nerve &
tectum.
Friday, January 16, 2015

36. Efferent connections.
Friday, January 16, 2015

37. Friday, January 16, 2015

38. Functions of cerebellum.
Control of body posture & equilibrium.
Control of muscle tone & stretch reflex.
Control of voluntary movements.
Friday, January 16, 2015

39. Control of body posture &
equilibrium.
Friday, January 16, 2015

40. Control of muscle tone &
stretch reflex.
Friday, January 16, 2015

41. Control of voluntary movements.
Friday, January 16, 2015

42. Mechanism of action.
Comparator function.
Damping action.
Timing & programming the movements.
Control of ballistic movements.
Servomechanism.
Friday, January 16, 2015

43. Comparator function.
Friday, January 16, 2015

44. Other functions of cerebellum.
Autonomic system (through Hypothalamus &
reticular formation.)
Ascending sensory pathway. (through
reticular formation & thalamus)
Eyeball movements. ( through vestibular
nuclei)
Friday, January 16, 2015

45. Cerebellar lesions.
Common causes.
Signs of cerebellar dysfunction.
Tests .
Friday, January 16, 2015

46. Common causes.
Vascular occlusions (thrombosis)
Tumor
Injuries.
Friday, January 16, 2015

47. Signs of cerebellar dysfunction.
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)
Friday, January 16, 2015

48. Signs of cerebellar dysfunction.
Equilibrium disturbance. (drunken gait)
Movements disturbance.
Ataxia
Intention tremors
Nystagmus.
Dysarthria.
Astasia.
Friday, January 16, 2015

49. Clinical tests of cerebellar
dysfunction.
Upper limb
Finger nose test
Diadokokinesia.
Rebound phenomenon.
Past pointing.
Lower limb.
Rombergs test.
Tandem gait.
Friday, January 16, 2015

50. Tests .
Friday, January 16, 2015

51. Thank
You