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Most nerve fibers are surrounded by an insulating, fatty sheath called myelin, which acts to speed up impulses. The myelin sheath contains periodic breaks called nodes of Ranvier.
By jumping from node to node, the impulse can travel much more quickly than if it had to travel along the entire length of the nerve fiber. Myelinated nerves can transmit a signal at speeds as high as 100 meters per second. If the myelin sheath surrounding nerve fibers is damaged or destroyed, transmission of nerve impulses is slowed or blocked. The impulse now has to flow continuously along the whole nerve fiber -- a process that is much slower than jumping from node to node. Loss of myelin can also lead to 'short-circuiting' of nerve impulses.
An area where myelin has been destroyed is called a lesion or plaque. This slowing and 'short-circuiting' of nerve impulses by lesions leads to a variety of symptoms related to nervous system activity. Symptoms can include sensory impairment, such as blurred vision, difficulties in controlling movement, and problems with bodily functions, such as failure to control urination. Demyelinating disease may result in vision or hearing loss, headaches, seizures, muscle spasms and weakness, loss of coordination, paralysis, and loss of sensation.
What else can I help you with?
What facilitates the rate of myelination?
Childhood experiences affect the rate of myelination in a child's brain. Myelination is the development of fatty sheaths around neurons, which help neurons communicate better and facilitates learning.
In what part of the brain does myelination occur last?
forebrain
What does gray matter lack that white matter has?
Myelination
What structure is responsible for myelination of the nerve fibers?
In the peripheral nervous system the cell that myelinates an axon is called a Schwann cell. In the central nervous system myelination is carried out by oligodendrocytes.
How long does full myelination take?
Full myelination of the central nervous system typically occurs by early adulthood. However, the process can vary depending on the specific region of the brain and individual factors.
A process called myelination increases how fast you process information?
True
What does terminal zones of myelination result on MRI in a child indicate?
Terminal zones of myelination on MRI in a child typically indicate the completion of myelination in specific brain regions, often reflecting normal developmental milestones. These zones can be seen as areas where myelin formation is nearing its final stages, which is expected in young children as their nervous systems mature. However, variations in myelination patterns may also raise considerations for developmental disorders or neurological conditions, and should be interpreted in the context of the child's overall clinical picture.
Does the the autonomic nervous system typically have thin fibers with little or no myelination?
yes.
Is myelination of the nerve fibers in the Central Nervous System the job of the oligodendrocyte?
True
Which two characteristics of axons increases the speed of nerve impulse?
diameter and presence of myelination.....
What are oligodendrocytes responsible for?
myelination of the axons and the dendrites are responsible for connection between the cell body and myelin
What does terminal zones of myelination result on mri in an adult indicate?
Terminal zones of myelination on an MRI in an adult typically indicate normal developmental myelination pattern seen in the brain. These are areas where myelin tracks end, resulting in a "tramline" appearance on imaging. It is a common finding in adults and does not usually indicate any pathology.
