1. The Cerebellum SHANDONG UNIVERSITY Liu Zhiyu

2. Position: lies above and behind the medulla oblongata and pons;
occupies posterior cranial fossa
Cerebellum

3. External features Three peduncles Inferior cerebellar peduncle
connect with medulla and spinal cord, contain both afferent and efferent fibers

4. External features Three peduncles Middle cerebellar peduncle
connect with pons, contain afferent fibers
Superior cerebellar peduncle
connect with midbrain, contain mostly efferent fibers

5. External features Tonsil of cerebellum
two elevated masses on inferior surface of hemisphere, just nearby foramen magnum

6. Lobes of cerebellum Two deep fissures Primary fissure
Posterolateral fissure
Three lobs
1. Flocculonodular lobe
flocculus and nodule
2. Anterior lobe
3. Posterior lobe
corpus of cerebellar

7. Lobes Anterior lobe corpus of Cerebellum Primary fissure
Posterior lobe
nodule
Flocculus
Flocculonodular lobe
Posterolateral fissure

8. Ⅱ. Internal structures Gray matter Cerebellar cortex Cerebellar nuclei
Dentate nucleus
Fastigial nucleus
Interposed nuclei
Emboliform nucleus
Globose nucleus

9. Ⅱ. Internal structures White matter— medullary center
Cerebellar cortex
Fastigial nucleus
Globose nucleus
Dentate nucleus
Emboliform nucleus
medullary center

10. Three functional divisions
Spinocerebellum ( paleocerebellum ) :
vermis and intermediate zone
Cerebrocerebellum (neocerebellum ):
lateral zone
Vestibulocerebellum ( archicerebellum): Flocculonodular lobe and vestibular nuclei
vermis
intermediate zone
lateral zone
Flocculonodular lobe

11. Middle cerebellar peduncle
Ⅲ. Connections and peduncles of cerebellum
Middle cerebellar peduncle
is composed of fibres which arises in the opposite side of the pontine nuclei and pass to the erebellum, transmit impulses which reach the the pons from the cerebral cortex.

12. inferior cerebellar peduncle
Ⅲ. Connections and peduncles of cerebellum
inferior cerebellar peduncle
This peduncle consists mainly of afferent fibres to the cerebellum，inlude
posterior spinocerebellar tract；
the fibers from the inferior olivary nucleus,
the fibers from vestibular
nuclei and nerve.
It also transmits efferent fibres to the medulla oblongata.

13. superior cerebellar peduncle
Ⅲ. Connections and peduncles of cerebellum
superior cerebellar peduncle
This is the principal efferent pathway from the cerebellum, its fibres arises mainly from the dentate nucleus, and passes anterosuperiorly to the opposite thalamus and red nucleus of the midbrain.

14. IV. Connections and function of cerebellum
Vestibulocerebellum
Afferents fibers receive input from vestibular nuclei and vestibular n..
Efferents fibers :
to the vestibular nucleus
→ vestibulospinal tract → anterior horn.of spinal cord.
→ medial longitudinal fasciculus → motor nuclei asociated with movement of eyeball。
Function: involved in eyeball movements and maintain the balance of the body

15. IV. Connections and function of cerebellum
Spinocerebellum
Afferent fibers:
receive somatic sensory information via spinocerebellar tracts.
Efferent fibers:
to the fastigial nucleus→ vestibular nuclei → vestibulospinal tract → motor neurons of anterior horn

16. IV. Connections and function of cerebellum
Spinocerebellum
Efferent fibers:
to the interposed nuclei中间① contralateral red nucleus → rubrospinal tract →motor neurons of anterior horn of spinal cord
② contralateral thalamus→cerebral cortex

17. IV. Connections and function of cerebellum
Spinocerebellum
Function:
play an important role in control of muscle tone and coordination of muscle movement on the same side of the body

18. IV. Connections and function of cerebellum
Cerebrocerebellum
Afferents: receives input from the cerebral cortex via the pontine nuclei middle cerebellar peduncle
Efferents: to dentate nucleus → contralateral thalamus → primary motor cortex → corticospinal tract → motor neurons of anterior horn
Function: coordination of muscle movement of limbs.