Myelin sheaths are located around the nerve cells. In central as well as peripheral nervous system.
Your question is not complete. There is not enough information. What are you referring to as "they". Some nerve fibers have thick myelin sheaths and some don't.
By myelin sheath.
In a typical neuron, sheaths of fatty tissue are called the Myelin sheath. The myelin sheath surrounds parts of the axon of a nerve cell which speeds up neurotransmitters.
Oligodendrocyte; processes of the oligodendrocytes form the myelin sheaths around the CNS nerve fibers
Building myelin sheaths and cell membranes requires an adequate supply of essential nutrients, particularly fatty acids like omega-3 and omega-6. Phospholipids are also crucial for membrane structure and function. Additionally, the presence of certain proteins, such as myelin basic protein, is necessary for the formation and maintenance of myelin sheaths.
myelin sheaths
No, they form myelin sheaths on axons in the CNS while schwann cells form myelin sheaths in the PNS. Hope this answers your question.
No, myelin sheaths actually speed up nerve impulses by increasing the speed of signal transmission along the nerve fibers. This is due to the insulation effect of myelin, which helps to prevent signal loss or leakage.
MS
No. It does not. It can not. It neither affect the neurons also.
Schwann cells in the peripheral nervous system form myelin sheaths around axons, which helps to speed up the transmission of nerve impulses. These myelin sheaths act as insulating layers that ensure efficient communication between neurons.
the myelin sheaths. The disease is classified as demyelinating , which is also known as the degeneration of the myelin structures in the neuron.