What Is the Cerebellum?

It is easy to spot when examining the brain because it appears almost as a separate structure at the bottom, beneath the cerebral hemispheres. While the cerebrum has broad, irregular grooves, the cerebellum, in contrast, features parallel grooves that are finely spaced, lending this section much visual distinction.

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It has several parts including a folded layer of cortex, a fluid-filled ventricle, white matter, and nuclei that are embedded in the white matter. Other parts of the cerebellum are the nodulus, flocculonodular lobe, flocculus, horizontal fissure, primary fissure, posterior lobe, anterior lobe, and vermis. It also contains what the medical community dubs “microzones” that are mapped out with geometric precision.

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The cerebellum is integral when it comes to the body’s ability to maintain balance. Within it, tiny sensors detect movement and shifts in balance. They send out signals that trigger the body to adjust to these shifts to maintain balance. Scientists have learned much about this part of the brain and its role in balance by working with patients with injured cerebellums.

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For the body to move at will, multiple muscles must work in conjunction with one another, which requires considerable coordination. Cerebellums provides this coordination, controlling events such as the timing of muscle movement, a vital part of voluntary movements like walking, running, jumping, or grabbing. Various muscle groups receive signals from the brain regarding how they should act -- these signals stem from the cerebellum.

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Without a cerebellum, it would be impossible to learn how to ride a bike, play the piano, or perform a gymnastics routine. It is involved in how the brain learns muscle movement and how it hones those movements for improvement. As a ballet student develops into a ballerina or a piano novice grows into a professional pianist, they have their cerebellum to thank for its ability to fine-tune action and controlled movement.

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The cerebellum coordinates movement via its intricate neural network, which includes the eyes. A healthy cerebellum is essential for ocular motor functionality. Essentially, it allows the eyes to focus on objects that we wish to see more clearly. As such, an injury or disorder affecting it can greatly impede vision.

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Like much of the brain, the cerebellum’s inner workings and involvement in other functions like thinking and mood are not entirely understood. Scientists suspect it has a role to play in these functions, but not enough study has been conducted for them to understand precisely how the cerebellum supports these aspects of living. As scientists conduct more research on the brain, we are sure to learn more about the cerebellum and its workings.

Problems with muscle control are the most obvious signs of a cerebellum disorder. Injury to the cerebellum can result in reduced or lost muscle control, but various conditions can also affect this part of the brain. Stroke, genetic abnormalities, tumors, toxins, and infection can damage the cerebellum and cause malfunction. Other symptoms of a cerebellum disorder include blurred vision, changes in thinking, mood disturbances, trouble swallowing, loss of coordination, and slurred speech.

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As the body ages, the cerebellum may suffer a loss of neurons. Age-related conditions like dementia or Alzheimer’s disease can also affect performance, particularly its role in cognitive function. Research indicates this though researchers still are not sure of the exact role the cerebellum plays in processes like thinking. The death of neurons in the cerebellum can lead to reduced motor function and diminished coordination and balance.

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Supporting overall brain health is key to protecting the health of the cerebellum. Medical caregivers advise people to reduce their risk for conditions like stroke by ceasing to smoke and curbing alcohol intake. Exercise and a healthy diet can also support brain health. People should take care to avoid environmental or industrial toxins like lead. Wearing helmets or protective gear when playing sports and wearing a seatbelt in the car can also help protect the cerebellum from injury.

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