For first year anatomy students, description of cerebellum.

1. Cerebellum ( Laghumastishka / dhamilak))
• Largest part of hind brain
• Position- Behind pons & medulla
• Separated from them by 4th ventricle
• Skull- post cranial fossa
• Dural folds - tentorium crebeli / falx cerebelli
• Constitutes only 1/10th of brain , but if unfolded -• Constitutes only 1/10th of brain , but if unfolded -
surface area becomes half of the cerebral cortex
• Cortex contains more neurons than cerebrum
• Function –
1. Co- ordination of fine movements
2. Balancing

5. • Outer- cortex ( neurons) / Inner- white mater ( Nuclei)
Structure
Ext features
Vermis Hemisheres
• Both are separated by deep paramedian fissure
Hemisheres

6. VermisHemishere

7. FoliaLobules
Lobes
FoliaLobules
Ant & post

8. • 4th ventricle projects inside white mater forming
fastigium(sloping roof)
• Ant / sup. medullary velum ( covering substance)
White mater forming its Cranial wall of 4th ventricle .
Extends as a thin sheet in the roof of 4th ventricle
• Lat boundary- Sup cerebellar peduncles
Other features
• Lat boundary- Sup cerebellar peduncles
• Contains decussation of trochlear nerve

11. Surfaces
Sup
Flat.
Adjoins Tentorum cerebelli.
Paramedian sulci are shallow

13. Inf
•Massive hemisheres
overlapping vermis
•Paramedian sulci- deep
•Post- cerebellar notch
Containing falx cerebelliContaining falx cerebelli

14. Post cerebellar notch
Paramedian sulcus

15. • Each lobule is continuous with bilat. Lobe except
lingula
• Fissura prima- Marks boundary bet. Ant & post
lobes( culmen - declive)
• Horizontal fissure- Separates Sup & Inf surface

16. Divisions of hemisphere (Sup)
•Ant lobe
•Post quadrangular lobule•Post quadrangular lobule
•Sup. Semilunar lobule

17. Divisions of hemisphere (Inf)
Inf semilunar (Post)
• Biventral lobule
Tonsil- Spherical , on inf aspect of post lobe
• Flocculus (Ant)
Retrotonsillar fissure

19. Divisions of vermis (Sup) & continuation
Central
lobule
Culmen-
(summit)
Declive-
(slope)
Folium vermis-
(leaf)
Alae Ant.
Quadrangular
lobule
Post
Quandrangular
lobule
Sup. Semilunar
lobule

20. Divisions of vermis (inf.) & continuation
Tuber vermis Pyramis Uvula Nodule
Inf semilunar
lobule
Biventral
lobule
Biventral
lobule &
flocculus

23. White mater-
• Occupies central part.
• Tree like pattern of medullary laminae – Arbour
vitae
• Contains aff & eff. fibres from cortex.These cross in
Internal structure
• Contains aff & eff. fibres from cortex.These cross in
midline to form cerebellar commissure
• Laminae continue into a central mass which shows
nuclei – 1) Nucleus dentatus
2) Nucleus emboliformis / ant interposed
3) Globose / post interposed
4) Fastigii

25. • Med part of dentatus is hilum- through which the
fibres come out to form sup. Cerebellar peduncle
Cerebellar pedunccles
Middle InfSup
Largest & most
Lat. Connects to
Pons (Aff)
To medulla
Aff & eff
To midbrain
Eff from nuclei

28. Functional divisions
Archicerebellum
Floculonodular
Lobe + lingula
Paleocerebellum
Ant. Lobe ,
pyramid,Uvula.
Middle lobe ,
pyramid , uvula
Neocerebellum
Lobe + lingula
Controls axial
Musculature
Locomotion ,
equilibrium
pyramid,Uvula.
Controls tone ,
posture ,Crude
Movements of
limb
pyramid , uvula
Regulation of
Fine movements