Makes up 11% of the brain’s mass
Cerebellum (“little brain”)—two smaller
hemispheres located at the lower back
of the brain beneath the occipital lobes,
which coordinates body movements.
The outer layer, or cortex, of the
cerebellum consists of fine folds called
folia. As in the cerebrum, the outer layer
of gray matter surrounds the structure.
The cerebellum is at the back of the brain,
below the cerebrum. It's a lot smaller than
the cerebrum at only 1/8 of its size.
Because of your cerebellum, you can stand
upright, keep your balance, and move
around. Think about a surfer riding the
waves on his board. What does he need
most to stay balanced? The best surfboard?
The coolest wetsuit? Nope — he needs his
It is located behind the brain stem
right at the bottom of the brain. It
has a large mass of cerebral cortex
above and a portion of the brain
Cerebellum is divided into two
hemisphere, and has a cortex that
surrounds these hemispheres.
The Cerebellum consists of two
cerebellar hemisphere united in the
midline by the vermis
Three fiber bundles called cerebellar peduncles connect
the cerebellum to the three parts of the brain stem—
the midbrain, the pons, and the medulla oblongata.
The Three Peduncles
medulla and the
The cerebellum coordinates
voluntary movements by fine-
tuning commands from the
motor cortex in the cerebrum.
The cerebellum also maintains
position and balance by
controlling muscle tone and
sensing the position of the
limbs. All motor activity, from
hitting a baseball to fingering
a violin, depends on the
If there is any traumatic brain injury or brain cancer, the
function of cerebellum may go out of order. It causes slow
and uncoordinated movements in the body. Therefore,
people with cerebellum injuries sway and stagger while they
walk. The damage to cerebellum may lead to many problems
in an individual.
What happens when the part doesn’t
Asynergia: This is loss of coordination of motor movement.
Dysmetria: The person finds it difficult to judge distance and
when to stop.
Adiadochokinesia: This is a condition where the person is unable
to perform rapid alternating movements.
Intention tremor: The patient may tremor while carrying out
Ataxic gait: Staggering and swaying while walking.
Hypotonia: A person develops weak muscles.
Ataxic dysarthria: Development of slurred speech.
Nystagmus: Abnormal eye movements.
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structures and their implications for cerebellar
function". Annu. Rev. Neurosci. 31: 1–24.
Houk JC, Buckingham JT, Barto AG (1996). "Models of
the cerebellum and motor learning". Behav. Brain
Sci. 19 (3): 368–383.