The cerebellum is located in the posterior fossa of the skull below the brain. It has three main lobes - the anterior, middle, and flocculonodular lobes. The cerebellum coordinates voluntary movement through connections with other parts of the brain and spinal cord. It has an outer gray matter cortex containing Purkinje cells and an inner white matter. The cerebellum receives sensory information and regulates motor movements to produce smooth, coordinated activity.

1. THE CEREBELLUM
(RABBIA YOUSAF)

2. DESCRIPTION
 The cerebellum, or “small brain”
 The adult human cerebellum weighs
approximately 150 g (10 percent of brain
weight).
 The cerebellum is somewhat ovoid in shape .

3. LOCATION
 The cerebellum is located in the posterior fossa of
the skull.
 It overlies the dorsal surfaces of the pons and
medulla oblongata and contributes to the formation
of the roof of the fourth ventricle.
 It consists of two cerebellar hemispheres joined by a
narrow median vermis.
 The cerebellum is connected to the posterior aspect
of the brainstem by three symmetrical bundles of
nerve fibers called the superior, middle, and
inferior cerebellar peduncles.

5. Gross Appearance of the
Cerebellum
The cerebellum is divided into three main lobes:
1. The anterior lobe
2. The middle lobe
3. The flocculonodular lobe

7. Fissures
 Primary fissure: separates anterior and posterior
lobes
 Horizontal fissure: separates posterior lobe from its
caudal lobules
 Posterolateral fissure: separates posterior and
flocculonodular lobes

9. The anterior lobe
 seen on the superior surface of the cerebellum and
is separated from the middle lobe by a wide V-
shaped fissure called the primary fissure.
The middle lobe (or posterior lobe)
 the largest part of the cerebellum, is situated
between the primary and posterolateral fissures.
The flocculonodular lobe
 situated posterior to the uvulonodular fissure.

12. Functional Areas of the
Cerebellar Cortex

13. Functional Areas of the
Cerebellar Cortex
Lobe Function
Vermis proximal musculature
of limbs
Intermediate
Hemisphere
Distal musculature
Lateral Hemisphere Motor Planning and
Conscious
Assessment of
movement errors

14. Structure of the Cerebellum
 The cerebellum is composed of an outer covering of
gray matter called the cortex and inner white matter.
 Embedded in the white matter of each hemisphere
are masses of gray matter forming the
intracerebellar nuclei.

15. Gray Matter Of cerebellum
 The gray matter of the cortex throughout its extent
has a uniform structure. It may be divided into three
layers:
1. an external layer, the molecular layer.
2. a middle layer, the Purkinje cell layer.
3. an internal layer, the granular layer.

16. Molecular Layer
It is the outermost layer and contains two types of
neurons: the outer stellate cell and the inner basket
cell as well as parallel fibers which are the axons of
granule cells. The extensive dendritic tree of the
Purkinjie cell extends into molecular layer.
Purkinje Cell Layer
 It is the middle and most important layer of the
cerebellar cortex.
 only axons of purkinje cells leave the cerebellar
cortex.
 A SINGLE AXON exits from each purkinje cell and
projects to one of the deep cerebellar nuclei or to
vestibular nucleus of brain stem

18. The granule cell layer
 Innermost layer of cerebellar cortex
 It contains Golgi cells, granule cells, granule cell is
the only excitatory neuron with in cerebellar cortex.

19. Name Target Transmitter Function
Purkinje cell Deep
Cerebellar
Nuclei,
Vestibular n
GABA Inhibitory
Granule cell Purkinje cell Glutamate Excitatory
Stellate cell Purkinje cell GABA Inhibitory
Basket cell Purkinje cell GABA Inhibitory
Golgi cell Granule cell GABA Inhibitory

20. Intracerebellar Nuclei
 From lateral to medial, these nuclei are
1. the dentate,
2. the emboliform,
3. the globose,
4. the fastigial.

22. White Matter
 The intrinsic fibers do not leave the cerebellum but
connect different regions of the organ.
 The afferent fibers form the greater part of the
white matter and proceed to the cerebellar cortex.
 They enter the cerebellum mainly through the
inferior and middle cerebellar peduncles.

24. FUNCTION OF CREBELLUM
 The cerebellum receives information from the
sensory systems, the spinal cord, and other
parts of the brain and then regulates motor
movements. The cerebellum coordinates
voluntary movements such as posture ,
balance, coordination, and speech , resulting
in smooth and balanced muscular activity.