cerebellum.pptx

Your cerebellum is part of your brain that helps coordinate and regulate a wide range of functions and processes in both your brain and body. While it's very small compared to your brain overall, it holds more than half of the neurons (cells that make up your nervous system) in your whole body.

1. Cerebellum Presenter - Rahul Sharma

2. Contents Gross appearance of cerebellum Structure of cerebellum Functional division of cerebellum Afferent & efferent pathways Clinical MCQ’s Clinical Vignettes

3. Gross appearance of cerebellum Situated in the posterior cranial fossa It consist Two lobes Joined by narrow median vermis

4. Connected by 3 peduncle Superior cerebellar Middle cerebellar Inferior cerebellar

5. Divided in 3 main lobes Superior lobe Middle lobe Flocculonodular lobe 3 fissure are present Primary fissure Horizontal fissure Uvulonodular fissure

6. 3 layers:- Molecular layer Purkinje cell layer Granular layer Structure of cerebellum

7. Figure 6-3 A: Flattened view of the cerebellar cortex showing the main cerebellar lobes, lobules, and fissures. Functional areas of cerebellar cortex 3 functional areas Cortex of vermis Intermediate zone Lateral zone

8. Intracerebellar nuclei 4 mass of grey matter embedded in white matter Nuclei Dentate Emboliform Globose Fastigial Intracerebellar nuclei are composed of large multipolar

9. White Matter Composed of 3 group of fibres Intrinsic fibre Do not leave cerebellum Connect different region of organ Afferent Form greater part of white matter Enter mainly from inferior & middle peduncle Efferent nerve Output of cerebellum Note:- dentate, emboliform & globose nuclei fibre leave from superior cerebellar peduncle and fibres from fastigial leave through inferior cerebellar peduncle

10. Cerebellar Cortical M echanism Two main line of input Mossy fibre Climbing fibre Excitatory to P urkinje cell What then is the function of other cell of cerebellum? Basket cell, stellate cell, golgi cells

11. Cerebellar Afferent F ibers From cerebral cortex Corticopontocerebellar pathway Cerebro-olivocerebellar pathway Cerebroreticulocerebellar pathway Figure 6-10 Cerebellar afferent fibers from the cerebral cortex.

12. Cerebellar afferent fibers from spinal cord Figure 6-11 Cerebellar afferent fibers from the spinal cord and internal ear. Anterior & Posterior spinocerebellar tract Cuneocerebellar tract Afferent fibre from vestibular nerve

13. Cerebellum Efferent Fibers Efferent fibre from cerebellum connect with:- Red nulceus Thalamus Vestibular complex Reticular formation

14. ARTERIAL SUPPLY OF CEREBELLUM Superior cerebellar artery Anterior inferior cerebellar artery Posterior inferior cerebellar artery

15. CLINICAL’S Lesions of cerebellum: Due to trauma, vascular occlusion, tumors . Produce a number of signs and symptoms Acute lesions differ from those produced by chronic lesions.

16. Following symptoms and signs are characteristic of Cerebellar dysfunction . Hypotonia Postural Changes and Alteration of Gait Disturbances of Voluntary Movement (Ataxia) Dysdiadochokinesia Disturbances of Reflexes Nystagmus Disorders of Speech

17. Cerebellar Syndromes Vermis Syndrome Common cause of vermis syndrome is medullo blastoma of vermis Involvement of flocculonodular lobe Signs and symptoms related to vestibular system Muscle incoordination involves head and trunk and not the limbs

18. Cerebellar Hemisphere Syndrome Tumors of cerebellum result cerebellar hemisphere syndrome symptoms and signs are usually unilateral Ipsilataeral involvment of muscles Movements of limbs, especially arms, are disturbed. Swaying and falling to the side of the lesion often occur. Dysarthria and nystagmus Lateral involvment of lobe result in delays in initiating movements and inability to move all limb segments together in a coordinated manner but show a tendency to move one joint at a time.

19. MCQ Superior cerbellar peduncle contains which of the following? Posterior spinocerebellar Olivocrebellar tract Vestibulocerebellar Anterior spinocerebellar Anterior spinocerebellar BD_Chaurasia’s_Human_Anatomy , Volume 3 - Head-Neck and Brain 6th Edition, pg no 408

20. Which of the following region of cerebllum is concerned with planning and programming muscular activities? Intermediate zone Vermis Lateral zone Flocculonodular zone Lateral zone BD_Chaurasia’s_Human_Anatomy , Volume 3 - Head-Neck and Brain 6th Edition, pg no 408

21. Cerebellum consist numerous lobe, which lobe is the smallest one? Flocculonodular lobe Middle lobe Anterior lobe Posterior lobe BD_Chaurasia’s_Human_Anatomy , Volume 3 - Head-Neck and Brain 6th Edition, pg no 408 Flocculonodular lobe

22. Clinical Vignette Two physicians are talking in the street when one turns to the other and says, "Look at that man over there. Look at the way he is walking. He Is not swinging his right arm at all; it is just hanging down by his side. I wonder If he has a cerebellar lesion." Does a person with a unilateral cerebellar hemisphere tumor tend to hold the arm limply at the side when he walks? a unillateral lesion involving one cerebellar hemisphere demonstrates absence of coordination between different groups of muscles on the same side of the body Ans YES

23. References Richard_S_Snell_Clinical_Neuroanatomy_7 edition Gray's Anatomy-The Anatomical Basis of Clinical Practice 41st Edition - 2015