The document discusses the anatomy and functions of the cerebellum. It provides details on the three physiological divisions of the cerebellum - vestibulocerebellum, spinocerebellum, and cerebrocerebellum. It also describes the input and output pathways, neuronal circuitry, and key functions of the cerebellum, including precise timing of muscle movements, programming of ballistic movements, and motor learning. The main function of the spinocerebellum is the coordination and reciprocal contraction of agonist and antagonist muscles.

1. Cerebellum
Prof. Dr. Rashid Mahmood

2. MCQ 1 of 3
• A 55 years old man was referred to a neurologist with
complaints of ataxia and slurred speech. Examination
revealed that the patient had Nystagmus and was
unable to stand on his feet without support even with
his eyes open. This man is most probably suffering
from a lesion involving:
A. basal ganglia
B. dorsal columns
C. cerebellum
D. mid brain
E. spinal cord
6-Dec-17 Cerebellum | © Prof. Dr. Rashid Mahmood
C

3. MCQ 2 of 3
• A seventy year old man presents with rigidity of
much of the musculature of the body,
involuntary tremors & difficulty in initiating
movement. The most likely diagnosis is:
A. Alzheimer’s disease
B. Cerebellar Ataxia
C. Huntington’s Chorea
D. Parkinson’s disease
E. Thyrotoxicosis
6-Dec-17 Cerebellum | © Prof. Dr. Rashid Mahmood
D

4. MCQ 3 of 3
• A patient presents with a disturbance of
voluntary movements of one arm & leg,
decreased muscle tone, absent superficial
reflexes & slow deep reflexes. Which of the
following is diseased?
A. Cerebellum
B. Pyramidal Tract
C. Rubrospinal Tract
D. Basal Ganglia
E. Vestibule-Spinal Tract6-Dec-17 Cerebellum | © Prof. Dr. Rashid Mahmood
B

5. Components of motor movement that need
to be controlled
• Timing
• Rapidity
• Smooth progression from to next
movement
• Prediction of next movement
• Intensity when muscle load
changes
• Interplay between agonists and
antagonists
6-Dec-17 Cerebellum | © Prof. Dr. Rashid Mahmood
• Plan and Control Complex movements
• Relative intensities of separate
movements
• Direction of movements &
• Sequencing of multiple sequential
movements to achieve complicated
motor goal
Cerebellum Basal Ganglia

6. The Cerebellum
• Part of the hindbrain
• Makes up 11% of the brain’s
mass
• Cerebellar activity occurs
subconsciously
• Silent area of Brain
6-Dec-17 Cerebellum | © Prof. Dr. Rashid Mahmood

7. 6-Dec-17 Cerebellum | © Prof. Dr. Rashid Mahmood

8. Objectives
6-Dec-17 Cerebellum | © Prof. Dr. Rashid Mahmood
• Goal /Aim:
• By the end of this session students should be able to
understand the Physiology of Cerebellum
• Specific Objectives
At the end of the lecture the students will be able to
• Describe functional anatomy of cerebellum
• Explain connections of cerebellum to other parts of nervous
system
• Describe functions of cerebellum
• Enlist deep nuclei of cerebellum

9. Lesson Contents
•Functional Anatomy of Cerebellum
•Physiological divisions
•Deep Cerebellar Nuclei
•Afferent and Efferent pathways
•Neural Circuit
•Functions of Each Part of Cerebellum
6-Dec-17 Cerebellum | © Prof. Dr. Rashid Mahmood

10. Anatomical
Divisions
• Anterior lobe
• Primary Fissure
• Posterior Lobe
• Posterolateral Fissure
or
• Uvulonodular Fissure
• Flocculonodular
Lobe
6-Dec-17 Cerebellum | © Prof. Dr. Rashid Mahmood

11. Physiological
Divisions
Contd….6-Dec-17 Cerebellum | © Prof. Dr. Rashid Mahmood
Three Physiological
Divisions:
1. Vestibulo-
Cerebellum
Flocculonodular Lobe
2. Spino-
Cerebellum
Vermis +
intermediate zones
3. Cerebro-
Cerebellum
Lateral Zones

12. Assessment -1
•Name the Physiological divisions of Cerebellum.
6-Dec-17 Cerebellum | © Prof. Dr. Rashid Mahmood

13. 1. Vestibulo-Cerebellum
Flocculonodular Lobe
Control of Equilibrium
Contd….6-Dec-17 Cerebellum | © Prof. Dr. Rashid Mahmood

14. 2. Spino-Cerebellum
Vermis:
Movements of
• Trunk
• Shoulders
• Neck
• Hips
Intermediate Zone:
Movements of
Limbs:
Especially
Hands, Fingers,
Feet & Toes
Vermis + intermediate zones
Topographical representation of
muscle groups
6-Dec-17 Cerebellum | © Prof. Dr. Rashid Mahmood

15. 3. Cerebro-Cerebellum
Lateral Zones
Planning and coordination of sequential motor
activities
Contd….6-Dec-17 Cerebellum | © Prof. Dr. Rashid Mahmood

16. Deep cerebellar nuclei
6-Dec-17 Cerebellum | © Prof. Dr. Rashid Mahmood
• Outer: Grey matter (cortex)
• Inner: White matter
Groups of nerve cell bodies embedded in white
matter
Three
1. Fastigial nucleus
2. Interposed nucleus

17. Internal structures
Cerebellar cortex
Dentate nucleus
Fastigial nucleus
Globose nucleus
Emboliform nucleus
Arbor vitae
6-Dec-17 Cerebellum | © Prof. Dr. Rashid Mahmood
Globose Nucleus +
Emboliform Nucleus =
interposed Nucleus

18. Afferent & Efferent Pathways
Input Signals:
i. From respective body parts
ii. Corresponding topographical areas of motor
cortex
Output Signals:
i. Same areas of motor cortex
ii. Red nucleus
iii. Reticular formation
Contd….6-Dec-17 Cerebellum | © Prof. Dr. Rashid Mahmood

19. Downloaded from: StudentConsult (on 17 December 2012 04:46 AM)
© 2005 Elsevier
Three peduncles:
Superior cerebellar
peduncle :Midbrain
Middle cerebellar
peduncle :Pons
Inferior cerebellar
peduncle :Medulla
Principal afferent tracts to the cerebellum.
6-Dec-17 Cerebellum | © Prof. Dr. Rashid Mahmood

20. Ventral organization
6-Dec-17 Cerebellum | © Prof. Dr. Rashid Mahmood

21. Principal afferent tracts to the cerebellum.
A. Input Pathways from Brain
Four main tracts/ pathways:
i) Cortico-Ponto-Cerebellar pathway
ii) Olivocerebellar Tract
iii) Vestibulocerebellar Tract
iv) Reticulocerebellar Tract
B. Input Pathways From Periphery
Four main tracts/ pathways
i) Two Doral spinocerebellar tracts
ii) Two Ventral Spinocerebellar tracts
Contd….6-Dec-17 Cerebellum | © Prof. Dr. Rashid Mahmood

22. Spinocerebellar tracts. Downloaded from: StudentConsult (on 17 December 2012 04:46 AM)
© 2005 Elsevier
6-Dec-17 Cerebellum | © Prof. Dr. Rashid Mahmood

23. Spinocerebellar Tracts
6-Dec-17 Cerebellum | © Prof. Dr. Rashid Mahmood

24. Assessment Q.2
•Name the input pathways of Cerebellum
that originate in the periphery
6-Dec-17 Cerebellum | © Prof. Dr. Rashid Mahmood

25. Outway Pathways From Cerebellum
All out put signal originate (pass through) in deep nuclei brain
6-Dec-17 Cerebellum | © Prof. Dr. Rashid Mahmood
Three Major
Output
Pathways

26. 6-Dec-17 Cerebellum | © Prof. Dr. Rashid Mahmood
Vermis Intermediate Zone Lateral Zone
Fastigial nuclei
Medulla & Pons
Interposed nucleus
Thalamus
Cerebral cortexBasal Ganglia
Red nucleus & reticular formation
Dentate nucleus
• Equilibrium
• Postural
attitudes
Coordination and
reciprocal
contractions of
agonist and
antagonist muscles
(esp. hands and
fingers)
Planning and
coordination of
sequential
movements

27. Cerebral and
cerebellar control of
voluntary
movements
Downloaded from: StudentConsult (on 17 December 2012 04:46 AM)
© 2005 Elsevier
Input & Output Pathways
6-Dec-17 Cerebellum | © Prof. Dr. Rashid Mahmood

28. Neuronal Circuit
30 Million functional units
Center: Single large Purkinje
cell
6-Dec-17 Cerebellum | © Prof. Dr. Rashid Mahmood

29. Left: basic neuronal circuit of the
cerebellum
excitatory neurons: red
Purkinje cell (an inhibitory
neuron): black Downloaded from: StudentConsult (on 17 December 2012 04:46 AM)
© 2005 Elsevier
Right: physical relationship of
the deep cerebellar nuclei to
the cerebellar cortex with its
three layers
6-Dec-17 Cerebellum | © Prof. Dr. Rashid Mahmood
1
2
3
6
5
4
7a 7b
8
9
10

30. 6-Dec-17 Cerebellum | © Prof. Dr. Rashid Mahmood

31. 6-Dec-17 Cerebellum | © Prof. Dr. Rashid Mahmood
Control of
deep
cerebellar
Nuclei

32. 6-Dec-17 Cerebellum | © Prof. Dr. Rashid Mahmood
Connections of
the Climbing
fibers with Deep
Nuclei

33. 6-Dec-17 Cerebellum | © Prof. Dr. Rashid Mahmood

34. Assessment-3
•Name the two types of Ascending
Fibers that supply to a deep nuclear cell
in a Cerebellum Unit.
6-Dec-17 Cerebellum | © Prof. Dr. Rashid Mahmood

35. Functions of Cerebellum
1. Timing of motor activities
Turn-On Turn-Off Signal
2. Rapid, smooth progression from one movement to
next
3. Intensity of muscle contraction when muscle load
changes. (Basal Ganglia: Relative intensities of
separate movements)
4. Interplay between agonist and antagonist muscle
groups (Basal Ganglia: Plan and control
complex pattern of muscle movements)6-Dec-17 Cerebellum | © Prof. Dr. Rashid Mahmood

36. Functions of Vestibulocerebellum
6-Dec-17 Cerebellum | © Prof. Dr. Rashid Mahmood
1. Equilibrium
2. Postural movements
3. Rapid movements
4. Movements that involve rapid changes
in direction
5. Calculates where body parts will be after
next few milliseconds
From:
1. Position of different parts
2. Speed of movement
3. Direction of movement

37. Functions of Spinocerebellum
1. Coordination and reciprocal contraction of agonist and
antagonist muscles Turn-on Turn-off signals
Spinocerebellum receives three types of information when a
movement is performed: COMPARES
i) Direct information from motor cortex & Red nucleus, telling
cerebellum about intended movement
(Cortico-Ponto-Cerebellar Tract)
ii) From Sensory Relay Neurons: Tells cerebellum that signals have
arrived
(Ventral Spinocerebellar Tract)
iii) From Sensory Receptors: Tells that Actual Movement has occurred
Contd….6-Dec-17 Cerebellum | © Prof. Dr. Rashid Mahmood

38. Functions of Spinocerebellum (Contd…)
6-Dec-17 Cerebellum | © Prof. Dr. Rashid Mahmood
2. Damping function:
Pendulous / overshoot If not stopped at intended point.
3. Control of ballistic movements:
Most rapidly occurring movements e.g. Typing,
Preplanned
Cerebellum Removed:
i. Movements slow to develop
ii. Force development is weak
iii. Slow to Turn-off
iv. Loss of Automatism

39. Functions of Cerebro Cerebellum:
• No direct input from peripheral body parts
• Two-way communication with cerebral cortex and
basal ganglia
1. Planning & coordination of sequential movements
Smooth Progression Orderly sequence
2. Timing Function
Time the sequential movements when to start and stop
3. Extramotor predictive function
Can predict from changing visual scenes how rapidly a person
is approaching an object.
6-Dec-17 Cerebellum | © Prof. Dr. Rashid Mahmood

40. Learning Resources
6-Dec-17 Cerebellum | © Prof. Dr. Rashid Mahmood
• Guyton and Hall (Text book of physiology), 13th
Edition
• Ganong (Text book of physiology), 25th Edition
• Lecture Notes Neurophysiology by Prof. Dr.
Muhammad Tariq 2nd Edition, Reprint (Co-
Author: Prof. Dr. Rashid Mahmood)
• Neurophysiology for Medical Students by Prof.
Dr. Masood Ahmed Khan 2nd Edition (Co-Author:
Prof. Dr. Rashid Mahmood)

41. Summary of functions of Cerebellum
6-Dec-17 Cerebellum | © Prof. Dr. Rashid Mahmood
•Provides precise timing and appropriate
patterns of skeletal muscle contraction
•Programming ballistic movements
•Acts as comparator for movements
•Correction of ongoing movements
•Coordinating body & eye movement
•Maintaining balance
•Motor learning

42. Take Home Points
•Equilibrium & Posture
•Vestibulocerebellum
•Distal limb movement control by feedback
•Spinocerebellum
•Plan, sequence & times complex movement
•Cerebrocerebellum
6-Dec-17 Cerebellum | © Prof. Dr. Rashid Mahmood

43. Assessment Q.4
•What is the main function of
Spinocerebellum?
6-Dec-17 Cerebellum | © Prof. Dr. Rashid Mahmood

44. The End
Questions ?
Comments ?
drrashid62@gmail.com
rashid.mahmood@rmi.edu.pk
ppt also available at
https://www.slideshare.net
Cerebellum | © Prof. Dr. Rashid6-Dec-17

45. Thank You
6-Dec-17 Cerebellum | © Prof. Dr. Rashid Mahmood