Transcript The Cerebellum

The Cerebellum
SHANDONG UNIVERSITY
Liu Zhiyu
Position:


lies above and behind
the medulla oblongata
and pons;
occupies posterior
cranial fossa
Cerebellum
External features

Three peduncles
Inferior cerebellar
peduncle
connect with medulla and
spinal cord, contain both
afferent and efferent
fibers
External features

Three peduncles
Middle cerebellar
peduncle
connect with pons, contain
afferent fibers
Superior cerebellar
peduncle
connect with midbrain,
contain mostly efferent fibers
External features
Tonsil of cerebellum
two elevated masses
on inferior surface of
hemisphere, just
nearby foramen
magnum
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
Lobes
Anterior
lobe
Primary fissure
corpus of
Cerebellum
Posterior
lobe
Flocculus
Posterolateral fissure
nodule
Flocculonodular lobe
Ⅱ. Internal structures
Gray matter

Cerebellar cortex

Cerebellar nuclei
Dentate nucleus
Fastigial nucleus
Interposed nuclei
Emboliform nucleus
Globose nucleus
Ⅱ. Internal structures
White matter—
medullary center
Cerebellar cortex
Fastigial nucleus
Globose nucleus
Dentate nucleus
medullary center
Emboliform nucleus

Three functional divisions
Spinocerebellum
( paleocerebellum ) :
vermis and intermediate
zone
Vestibulocerebellum
( archicerebellum):
Flocculonodular lobe and
vestibular nuclei
lateral zone

intermediate zone
Cerebrocerebellum
(neocerebellum ):
lateral zone
vermis

Flocculonodular lobe
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.
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.
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.
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

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
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
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
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.