Anatomy of the Cerebellum and its Function

In Latin, the word cerebellum means little brain. The cerebellum is the area of the hindbrain that controls movement coordination, balance, equilibrium and muscle tone. Like the cerebral cortex, the cerebellum is comprised of white matter and a thin, outer layer of densely folded gray matter. The folded outer layer of the cerebellum (cerebellar cortex) has smaller and more compact folds than those of the cerebral cortex. The cerebellum contains hundreds of millions of neurons for processing data. It relays information between body muscles and areas of the cerebral cortex that are involved in motor control.

Cerebellum Lobes

The cerebellum can be subdivided into three lobes that coordinate information received from the spinal cord and from different areas of the brain. The anterior lobe receives input primarily from the spinal cord. The posterior lobe receives input primarily from the brainstem and cerebral cortex. The flocculonodular lobe receives input from the cranial nuclei of the vestibular nerve. The vestibular nerve is a component of the vestibulocochlear cranial nerve. The transmission of nerve input and output signals from the cerebellum occurs through bundles of nerve fibers called cerebral peduncles. These nerve bundles run through the midbrain connecting the forebrain and hindbrain.

Cerebellum Function

The cerebellum is involved in several functions including:

• Fine movement coordination
• Balance and equilibrium
• Muscle tone
• Sense of body position

The cerebellum processes information from the brain and peripheral nervous system for balance and body control. Activities such as walking, hitting a ball and playing a video game all involve the cerebellum. The cerebellum helps us to have fine motor control while inhibiting involuntary movement. It coordinates and interprets sensory information in order to produce fine motor movements. It also calculates and corrects informational discrepancies in order to produce the desired movement.

Cerebellum Location

Directionally, the cerebellum is situated at the base of the skull, above the brainstem and beneath the occipital lobes of the cerebral cortex.

Cerebellum Damage

Damage to the cerebellum may result in difficulty with motor control. Individuals may have problems maintaining balance, tremors, lack of muscle tone, speech difficulties, lack of control over eye movement, difficulty in standing upright, and an inability to perform accurate movements. The cerebellum may become damaged due to a number of factors. Toxins including alcohol, drugs, or heavy metals can cause damage to nerves in the cerebellum that lead to a condition called ataxia. Ataxia involves the loss of muscle control or coordination of movement. Damage to the cerebellum may also occur as a result of stroke, head injury, cancer, cerebral palsy, viral infection, or nervous system degenerative diseases.

Divisions of the Brain: Hindbrain

The cerebellum is included in the division of the brain called the hindbrain. The hindbrain is divided into two subregions called the metencephalon and myelencephalon. The cerebellum and pons are located in the upper region of the hindbrain known as the metencephalon. Sagittally, the pons is anterior to the cerebellum and relays sensory information between the cerebrum and cerebellum.