Cerebellum

lectures of Neuroanatomy for second year Medical students by Dr. Noura El Tahawy

1. Cerebellum

By

Dr. Noura El Tahawy

2. Magnetic resonance images of the cerebellum of a 16-year-old
female. A, sagittal slice.

CEE TEL:

Moda tina —/ Formen mapın |

© Elsevier Ltd 2005. Standring: Gray's Anatomy 39e - www.graysanatomyonline.com

3. Magnetic resonance images of the cerebellum of a 16-year-old female.
coronal slice. C,

© Elsevier Ltd 2005. Standring: Gray's Anatomy 39e - www.graysanatomyonline.com

4. Cone

Sepals

Forte.

vei

focal tore

Elsevier Ltd 2005. Standring: Gray s Anatomy 396 - woew.qraysanat

tal cnt ay

Mode crab pasando

Pts tear bone

Sapos ort pal

Danae aes

Fat creel core,

Horizontal section through the cerebellum and brain stem.

5. Lobs

Three deep fissures

Primary fissure
Horizontal fissure

Posterolateral fissure
Three lobs

Flocculonodular lobe
flocculus and nodule

Anterior lobe

Posterior lobe

6. Lobs

Anterior lobe
d corpus of
Primary fissure Fi cerebellum

Posterior lobe

Flocculonodular lobe

LO hi

UE TD

7. _ Miebrain

Vermis Anterior lobe

Primary fissure

— Posterior lobe

Vallecula
‘Superior cerebellar peduncle

_ Middle cerebellar peduncle

Pyramis. \ Inferior cerebellar
peduncle

Tonsil Vallecula
© Elsevier FitzGerald et al: Clinical Neuroanatomy and Neuroscience Se - www.studentconsult.com

Cerebellum .A Viewed from above B Viewed from the position of the pons

8. Dentate nucieus
Primary fissure
—— Plane of section

Superior
cerebellar ——}

Pyramis
À peduncle

Tonsil

Dentate nucleus
© Elsevier. FitzGerald et al: Clinical Neuroanatomy and Neuroscience Se - www.studentconsult.com

A Sagittal section of hindbrain .B Oblique section of cerebellum

9. Internal

structure ¢

Gray matter

= Cerebellar cortex

= Cerebellar Medulla (White matter)
= Cerebellar nuclei

Dentate nucleus, Fastigial nucleus, Interposed
nucleus Emboliform nucleus

Globose nucleus

10. Internal structure

Cerebellar cortex b Fastigial nucleus

N Emboliform nucleus

Globose nuclei
medullary center

11. Cerebellar Cortex

Molecular Layer
Purkinje Cell Layer
Granular Layer

Corpus Medullare (Medullary Center)

Deep Cerebellar Nuclei

Fastigial Nuclei
Emboliform Nucleus
Globose Nucleus
Dentate Nucleus

13. The cerebellar cortex

Parallel fibre

urn
Granule cell cof folly
eas

+ Molecular layer

Purkinje cell

Granular layer

White matter

Climbing fibres from
I inferior olivary nucleus

Mossy firbre

Cerebellar nuclel

To brain stem and thalamus

Diagram shows afferent and efferent connections and their relationships to
the principal cells of the cerebellar cortex

14. A Cell layers B Afferent system

Molecular layer.
Piriform layer.

Granular layer

Mossy fiber.

Climbing fiber.

Central nucleus —|

P:
Basket cell

D Efferent system
© Elsevier. FitzGerald et al: Clinical Neuroanatomy and Neuroscience Se - wwwstudentconsult.com

Parallel fiber from
granule cell

Climbing fiber

Stellate cell

Golgi cell

Cerebellar cortex .A Cell layers B Afferent system .C Internuncial neurons .D
Efferent system

15. Three Anatomical Divisions

16. Superior surface

[Anterior lobe |
Quadrangular lobule (H NV)
Primary fissure
Horizontal fissure
Dat Simple lobule (H VI)
vermis Posterior lobe
Postlunate fissure

‘Superior semilunar
(anseriform) lobule (H VILA)

Horizontal fissure

ferior semilunar.
Posterior cerebellar notch —— (caudal) lobule (H VII 8)

Centrallobule—_____ Inferior surface

Superior vermis of central lobule
Lingua ()—

= : 2 | as une

Flocculonodular lobe
4th ventricle

Inferior medullary velum
Nodule (X)

inferior) Uvula (x)
Biventer lobule (H VII)
Tuber (Vil 8) ——— = Secondary (postpyramidal

fissure

Posterior cerebellar notch ———— Horizontal fissure

Inferior semilunar
(caudal) lobule (H VII 8

17. Three functional divisions

18. Superior vermis

Primary Anterk
¿— Anterior lobe
fissure

7 Hemisphere

Posterior
lobe

Horizontal
fissure

— —

fissure

— Inferior vermis

Flocculus —/
|
Flocculonodular lobe
© Elsevier. Crossman & Neary: Neuroanatomy 3e - www.studentconsult.com

Schematic drawing of the cerebellum in which the peduncles have been cut and the surface flattened
out. The relationships between the anatomical and functional divisions of the cerebellum are shown.

(Green, archicerebellum; blue, paleocerebellum; pink, neocerebellum.)

19. Three functional divisions

The archicerebellum corresponds to the flocculonodular lobe and
fastigial nucleus. Its principal connections are with the vestibular and
reticular nuclei of the brain stem and it is concerned with the
maintenance of equilibrium.

The paleocerebellum corresponds to the vermis and paravermal area,
together with the globose and emboliform nuclei. It receives fibres
from the spinocerebellar tracts and projects to the red nucleus of the
midbrain.

The neocerebellum corresponds to most of the cerebellar hemisphere
and the dentate nucleus. It receives afferents from the pons and

projects to the ventral lateral nucleus of the thalamus .

20. Connections & functions of the

cerebellum

21. Vestibulocerebellum

22. Vestibular
Organ

VESTIBULAR

vestibulospinal
& Reticulospinal tradts
MLF

lower motor neuron

LMN

—
ss

ARCHICEREBELLUM

23. Connections of the
Vestibulocerebellum
(archi-cerebellum).

Fastigial
nucleus

Reticular

Vestibular
nerve

Vestibulospinal and
reticulospinal tracts

(Contralateral projections of the fastigial nucleus are not shown)

24. Connections and function of Vestibulocerebellum

The archicerebellum is primarily concerned with the maintenance of balance
(equilibrium),

It recieves afferents from the vestibular and reticular nuclei of the brain stem,
passing through the inferior cerebellar peduncle:

Vestibular information is then carried from the vestibular nuclei to the cortex of the
ipsilateral flocculonodular lobe. Cortical cerebellar efferent (Purkinje cell) fibres
project to the fastigial nucleus, which, in turn, projects back to the vestibular nuclei
and to the reticular formation

A significant proportion of fastigial efferents cross to the contralateral side of the
brain stem

The influence of the archicerebellum upon the lower motor system is, therefore,
bilateral and principally mediated by means of descending vestibulospinal and
reticulospinal projections (both end in AHCs of spinal cord).

Function: involved in eye movements and maintain balance

25. Spinocerebellum

26. ee of Main Connections of the

——

rubrospinal .
tract Inferior

Olivary
Nucleus

lower motor neuron
SPINAL CORD spinocerebellar

tracts

27. Connections of the
Spinocerebellum

(Paleocerebellum)

nucleus

Globose and

emboliform nuclei
Dorsal

spinocerebellar E Rubrospinal tract
tract

Ventral /
spinocerebellar tract —/

28. Connections and function of Spinocerebellum

(Paleocerebellum)
The paleocerebellum influences muscle tone and posture
Afferents consist principally of dorsal and ventral spinocerebellar tract neurones
that carry information from muscle, joint and cutaneous receptors and enter the
cerebellum through the inferior and superior cerebellar peduncles, respectively
Fibres terminate largely in the cortex of the ipsilateral vermis and paravermis.
Cerebellar cortical efferents from these areas pass to the globose and emboliform
nuclei and also to the fastigial nucleus.
The globose and emboliform nuclei project via the superior cerebellar peduncle to
the contralateral red nucleus of the midbrain, where they influence the activity of

cells giving rise to the descending rubrospinal tract .

29. Neocerebellum

30. CEREB THALAMUS
CORTEX LV nucleus

Red nucleus
pyramidal
tract
Pontine

Nucleus

lower motor neuron

31. Connections of the Neocerebellum.

Ventral lateral
nucleus of
thalamus

nucleus
Pontine nuclei

32. Connections and function of Neocerebellum

The neocerebellum is concemed with muscular coordination, including the trajectory, speed and force of movements
The principal afferent pathway consists of pontocerebellar fibers . (These originate in the pontine nuclei of the basal
portion of the pons and cross to the opposite side, entering the cerebellum through middle cerebellar peduncle
peduncle

Pontocerebellar neurons are influenced by widespread regions of the cerebral cortex involved in the planning and
execution of movement. Pontocerebellar fibres terminate predominantly in the lateral parts of the cerebellar
hemisphere

Output from the neocerebellar cortex is directed to the dentate nucleus. The dentate nucleus, in turn, projects to the
contralateral red nucleus and ventral lateral nucleus of the thalamus. The dentate is the largest of the cerebellar nuclei
and its efferents form a major part of the superior cerebellar peduncle

The fibres decussate in the caudal midbrain just before reaching the red nucleus. Some relay in the red nucleus with
rubrothalamic cells but most bypass the red nucleus and pass directly to the ventral lateral thalamus,

The ventral lateral nucleus of the thalamus projects to the cerebral cortex, particularly the motor cortex of the frontal
lobe

The neocerebellum thus exerts its coordinating role in movement primarily through an action on cerebral cortical

areas, giving rise to descending corticospinal and corticobulbar pathways

33. Principal cerebellar efferents.

Motor cortex —|

Thalamus

Ventral lateral nucleus
of thalamus

Midbrain
Red nucleus

[Superior cerebellar. Central tegmental tra
penduncle

Reticular formation
Cerebellum____2

Dentate nucleus — =
Interposed nur — VE
East tel uous inferior olivary nucleus

Vestibular nucleus.

© Etes FitzGerald tal: Clica! Neuroanatomy and Neuroscience Se - wm tudentconsul.com

Arrows indicate directions of impulse conduction

34. mn
bellum and Automatic Motor Control,

Motor Cortex
Red Nucleus

ae Vestibular
—

Lower Motor Neuron (LMN)

35. Functions of the cerebellum

< Maintenance of Equilibrium
- balance, posture, eye movement

< Coordination of half-automatic movement of
walking and posture maintenance
- posture, gait

< Adjustment of Muscle Tone

« Motor Learning — Motor Skills

“ Cognitive Function

36. Functions of the cerebellum

Balance

37. Functions of the cerebellum
Motor Skills

38. From this information the cerebellum

to produce steady volitional movements and
steady volitional postures.

is the main feature of cerebellar dysfunction. An
easy way to remember a cerebellar syndrome is to imagine a drunken
person who cannot coordinate any volitional movement. He sways when
standing, reels when walking, slurs words when talking and has jerky

eye movements when looking.

In addition, the muscles are loose and floppy

Thus, are the four
major clinical signs of the cerebellar syndrome.

39. Posture
Gait - Ataxia
Tremor

41. Cerebellar
Medulloblastoma

Cerebellar tumors on vermis
- Truncal Ataxia
- Frequent Falling

The child in this picture:

- would not try to stand
unsupported

- would not let go of the bed rail
if she was stood on the floor.

42. Cerebellar Peduncles

43. Midbrain

‘Middle cerebellar peduncle

Superior cerebellar peduncle

Cerebellar hemisphere

Inferior cerebotar peduncle

© Elsevier. Crossman & Neary: Neuroanatomy 3e - www.studentconsult.com

Lateral aspect of the brain stem and cerebellum, showing the cerebellar
peduncles .Parts of the anterior, posterior and flocculonodular lobes have been
removed to display the peduncles more clearly

44. >

© Elsevier. Crossman & Neary: Neuroanatomy 3e - www.studentconsult.com«

Anteroinferior aspect of the cerebellum, Showing the three cerebellar peduncles

45. Superior cerebellar
peduncle —

Middle cerebellar

peduncle

Posterolateral / y
fissure ——/ \
A—Nodule '— Flocculus

Inferior cerebellar |

peduncle
LL posterior lobe Flocculonodular
lobe

Anteroinferior aspect of the cerebellum., Showing the three cerebellar peduncles

46. Cerebral peduncle

¡ Superior carebellar peduncle
Tigeminal ‚Interior cerebellar
a peduncle

4 idée oerebielar

peduncle

Vestibulo-
cochigarnerve | Inferior cerebelar peduncte

© Elsevier Ltd 2005. Standring: Gray's Anatomy 39e - www.graysanatomyonline.co!

Dissection of the left cerebellar hemisphere and its peduncles.

47. Toms

[Super ante pende

fare ol ctr
[craw tes cesta
sgl mete

puts
roue

Fstgosina ae
ree ar cores

Red meus

Diosa
‘per cueca pasaras

Sacar atte caduco

Par cl
era pre

Cares ches 1 a

ose receta ac Arte pra et

Elsevier Ltd 2005. Standring: Grey's Anatomy 39e - www graysanatomyonine.com

potato
reste to

\— ner crenata
race

Ab

do. wire grotte we

Diagram illustrating the composition of the cerebellar peduncles. A, dorsal

view.-B, lateral view.

48. Tractology of the cerebellum

(Cerebellar Peduncles)

Inferior cerebellar Middle cerebellar | Superior cerebellar
peduncles peduncles peduncles

Afferents + Posterior 1. Pontocerebellar | 1. Anterior
spinocerebellar spinocerebellar
Cuneo-cerebellar 2. Tecto-cerebellar
(posterior external
actuate fibers)
Olivo-cerebellar
Parolivo-cerebellar
Vestibulo-cerebellar
Reticulo-cerebellar
Anterior external
ate fibers

Efferents e a 1. Cerebello- Dentato-rubral
bello-vestibular pontine Dentato-thalamic
Cerebello-reticular (LVN)
Dentato-olivary
Dentato-reticular

49. Blood Supply of the cerebellum

The posterior inferior cerebellar artery (from
vertebral artery) supplies the cerebellum &the

side of the medulla
The anterior inferior cerebellar and superior
cerebellar arteries (both arise from basilar

artery) supply the cerebellum& side of the pons

50. Anterior communicating artery

Anterior choroidal artery

Posterior communicating artery

>osterior cerebral artery —

Basilar artery —

Vertebral artery
‘Anterior spinal artery —

‘Anterior cerebral artery

Optic nerve
Middle cerebral artery

Internal carotid
artery
Oculomotor nerve

F
Superior cerebeliar
artery

Trigeminal nerve

Anterior inferior
cerebellar artery

Posterior inferior
cerebellar artery

© Elsevier. Crossman & Neary: Neuroanatomy 3e - www.studentconsult.com

51. Opticnenves
Ss

ise cerebral

Otrebellr ar

Postenor

Labintine artery ~

Posterior inferior
erebalar artery

© Elsevier Ltd 2005. Standring: Gray's Anatomy 39e - www.graysanatomyonline.com

The arteries on the base of the brain.

52. Thanks

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