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Aging changes in the nervous system
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| Aging changes in the nervous system |
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Information:
Although normal changes occur with age in the brain and nervous system, many people have misconceptions about the nature and extent of these changes. A common mistaken belief is the idea that all elderly people become senile. Many people blame increased confusion on "getting old" when it may, in fact, be caused by an illness. The nervous system has two divisions. The central nervous system consists of the brain and spinal cord. It processes nerve messages and controls movement, thought and behavior. The peripheral nervous system is made up of the nerves coming to and from the spine (spinal nerves) and the nerves in the body. This portion of the nervous system carries sensory and movement messages to and from the central nervous system. Text Continues Below
PHYSICAL CHANGES OF AGING
As people age, nerve cell mass is lost. This causes atrophy of the brain and spinal cord. Brain weight may decrease significantly from the maximum weight of young adulthood. The number of nerve cells decreases, and each cell has fewer branches (dendrites). Some nerve cells lose their coating in a process called demyelinization. These changes slow the speed of message transmission. After a nerve carries a message, there is a short time when it must rest and cannot carry another message (called the latency period). Aging increases the latency period. Waste products from atrophied nerve cells may collect in the brain tissue, causing plaques and tangles. Lipofuscin (a fatty brown pigment) may also accumulate in nervous tissue. These changes are not consistent in everyone. Some people have many physical changes in their nerves and brain tissue, others have few. Some will have atrophy and plaques, some will have plaques and tangles, and some will have other changes.
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