What is the process and function of myelination in the nervous system?

Answer 1

The function of myelination in the nervous system is to allow neural impulses to travel longer distances in axons quickly; the process is as follows: helper cells (glia) wrap either themselves (in the case of Schwann cells), or parts of themselves (in the case of oligodendrocytes), all along the length of a myelinated axon, with gaps between each wrapping, kind of like shis-kabobs; the wrapping insulates the axon, preventing ion leakage, such that the membrane potential at one gap (called a node of Ranvier) can directly affect the voltage-gated sodium ion pores at the next gap, thus moving the neural impulse more quickly than if the action potential were happening in all of the intervening spaces beneath the myelin sheaths. The action potential is re-triggered at each node, thus maintaining the strength of the impulse from start to finish along the whole length of the axon, while the electrotonic conduction under the myelin sheath provides the speed necessary for effective nervous system processing over longer distances.

Answer 2

Myelin is a fatty substance that surrounds the axons of nerves and is formed by oligodendrocytes (central nervous system) and Schwann cells (peripheral nervous system). The myelin sheath covers portions of the axon inhibiting the function of ion channels (such as Na+ and K+ gated channels) and pumps (Na+/K+) in the membrane, thus preventing an action potential to be propagated normally down the length of the axon. Gaps, called Nodes of Ranvier, do remain between sections of myelin sheath along the axon allowing for the conduction of an action potential to "jump" from node to node. This "jumping", referred to as saltatory conduction, allows for the action potential to reach the axon terminal faster than in an unmyelinated nerve, and is particularly useful on very long axons (such as from the spinal cord to the foot or arm, or even from the brain down the spinal cord). Multiple Sclerosis is an example of what happens when the myelin sheath is degraded in the central nervous system; movement along with other actions slows significantly as the series of nerve impulses takes longer to reach the musculature from the central nervous system.

Answer 3

Myelination is the process by which nerve fibers are covered with a fatty substance called myelin. This helps to insulate the nerve fibers and allows for faster and more efficient transmission of nerve impulses. Myelination is important for proper functioning of the nervous system, as it enhances signal conduction and helps maintain the integrity of the nerve fibers.