Cerebellum

The cerebellum is a part of the brain in humans and other animals. In Latin, the word cerebellum means "little brain." The cerebellum received its name because it is smaller than the cerebrum. The cerebellum is located near the brain stem at the back of the skull. This part of the brain is important for motor function in humans. The cerebellum also plays a part in other brain functions such as emotions. People who have damage to their cerebellum may have symptoms that include problems with fine motor function.

Background

The brain is the most important organ in humans. It allows humans to move, reason, and feel emotions. The human brain is extremely complex, and its different parts play different roles. Scientists have only just begun to understand the complexity of the human brain. The human brain is part of the central nervous system, which includes the brain, its cranial nerves, and the spinal cord. The brain is made up of proteins, and the brain of an adult human generally weighs about three pounds. The brain is one of the biggest organs in the human body. It includes approximately 100 billion nerve cells. These nerve cells, called neurons, allow the brain to function. The neurons collect signals that are sent along nerve fibers called axons and dendrites. The brain also has glial cells, which help provide support and nutrition to the brain. The brain has a number of different parts that help it function. The main parts of the brain are the brainstem, the cerebellum, the cerebrum, and the hypothalamus. The brain is protected by the bony cranium. Between the brain and cranium are three layers of tissue called the meninges. The meninges help protect the brain and spinal cord.

Overview

The cerebellum is one of the main parts of the brain. It is located at the back of the skull, underneath the occipital lobes of the cerebrum. It is attached to the brain stem. The cerebellum is the largest part of the hindbrain, which is a part of the brain stem and includes the cerebellum, pons, and medulla oblongata. The cerebellum is separated from the cerebrum by the tentorium, which is a fold in the membrane that surrounds and protects the brain. Although the cerebellum is only one-tenth the volume of the entire brain, it is the second-largest part after the cerebrum.

Although it is considerably smaller than the cerebrum, the cerebellum contains more neurons. It is covered in cortex, which is tightly folded gray matter. Underneath the gray matter is the white matter. The white matter of the cerebellum includes four cerebellar nuclei—the dentate nucleus, emboliform nucleus, globose nucleus, and fastigial nucleus. The cerebellum has two hemispheres, which are connected by a narrow structure called the vermis. The cerebellum is connected to the brain stem via three bundles of nerves. The superior cerebellar peduncle, or the superior brachium conjunctivum, is a bundle of nerves that connects that cerebellum to the midbrain. The middle cerebellar peduncle is the bundle of nerves that connects the cerebellum to the pons, which is part of the brainstem. The inferior cerebellar peduncle is the bundle of nerves that connects the cerebellum to the medulla oblongata, which is the lowest part of the brainstem, and partially to the pons.

One of the most important functions of the cerebellum is that it helps humans maintain posture and balance. The cerebellum directly connects to the brain stem and sends signals to motor neurons that help control movement. The cerebellum helps humans adjust their posture and maintain balance when loads shift or when bodies change position. Because of this, the cerebellum is considered a motor structure of the brain.

The cerebellum also plays an important role in other motor functions. It coordinates muscle groups that work together. Some movements that humans make require the use of multiple muscle systems. The cerebellum helps coordinate the groups so that the movements are fluid and the muscles work together. The cerebellum also helps humans learn new motor movements. For example, a person learning to hit a golf ball uses the cerebellum to fine-tune the new action. Although the cerebellum traditionally is considered a motor structure, it plays important roles other than motor function.

Injuries to the brain affect different aspects of people's lives. Injuries to the brain because of illness or other problems affect people differently based on where the injuries are located. Injuries to the cerebellum often create problems with motor function. Because the cerebellum is important for maintaining balance, people with cerebellum injuries often have balance disorders. If an individual has symptoms indicating cerebellum damage on only one side of the body, the damage to the cerebellum often is on the same side. For example, if an individual has impaired motor coordination on the right side, the cerebellum damage likely also is on the right side.

From the late 1800s, doctors and scientists realized that the cerebellum plays an important role in balance and movement. By the 1980s, they had realized that the cerebellum also plays an important role in other functions. From that time on, more brain functions have been attributed to being performed or assisted by the cerebellum. For that reason, the methods for identifying, classifying, and treating disorders of the cerebellum have changed over time. Furthermore, different types of disorders of the cerebellum may present different symptoms. However, a number of symptoms are common among cerebellum damage. Some of the most common symptoms relate to motor functions. People with damage to the cerebellum may have changes in muscle tone, impaired motor coordination, changes in gait and stance, changes in speech, and tremor. Since the late twentieth century, scientists have found that other symptoms are related to cerebellum damage, including changes in emotions and behavior.

Bibliography

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