How Does Myelin Affect The Transmission Of Nerve Impulses? Identify The Cells Responsible For The Formation Of Myelin

1830 Words Nov 15th, 2016 8 Pages
Part Two: Diagnosis and Treatment
7. What is myelin and how does it affect the transmission of nerve impulses? Identify the cells responsible for the formation of myelin.
Covering some axons is a multilayered lipid and protein called myelin sheath, this helps to insulate the axon and speed up nerve impulses. (Tortora pg. 407) An axon that is surrounded by myelin sheath, whether in the central nervous system (CNS) or the peripheral nervous system (PNS), is said to be “myelinated”, while the bare axon is “unmyelinated”. Action potentials travel more rapidly and further in distance along a myelinated axon, this is because they travel by salutatory conduction. This is when the impulse at the first node generates currents that open gated channels at each following node. Since an unmyelinated axon does not have nodes of Ranvier it travels by continuous conduction, which means the currents flow across each adjacent segment of the axon. This makes the impulse travel much slower along the unmyelinated axon. During infancy, the myelin sheath begins to form and it develops as you mature. This is why babies are not as responsive as adults, because the myelin sheath is not fully developed. There are two types of neuroglia that are responsible for producing myelin. In the CNS, processes of the oligodendrocyte form the myelin sheath which can cover parts of many axons. In the PNS, the Schwan cell is responsible for forming the myelin sheath, and can only myelinate one axon at a time.…

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