Search results
Results from the WOW.Com Content Network
Myelin (/ ˈ m aɪ. ə l ɪ n / MY-ə-lin) is a lipid-rich material that surrounds nerve cell axons to insulate them and increase the rate at which electrical impulses (called action potentials) pass along the axon. [1] [2] The myelinated axon can be likened to an electrical wire (the axon) with insulating material (myelin) around it. However ...
White matter is the tissue through which messages pass between different areas of grey matter within the central nervous system. The white matter is white because of the fatty substance (myelin) that surrounds the nerve fibers (axons). This myelin is found in almost all long nerve fibers, and acts as an electrical insulation.
It fully encases the fat droplet in an additional bilayer of phospholipids. The milk fat globule thus released into the glandular lumen, measuring 3-6 μm in average diameter, is surrounded by a phospholipid trilayer containing associated proteins, carbohydrates, and lipids derived primarily from the membrane of the secreting lactocyte.
A well-developed Schwann cell is shaped like a rolled-up sheet of paper, with layers of myelin between each coil. The inner layers of the wrapping, which are predominantly membrane material, form the myelin sheath, while the outermost layer of nucleated cytoplasm forms the neurilemma. Only a small volume of residual cytoplasm allows ...
To be specific, myelin wraps multiple times around the axonal segment, forming a thick fatty layer that prevents ions from entering or escaping the axon. This insulation prevents significant signal decay as well as ensuring faster signal speed. This insulation, however, has the restriction that no channels can be present on the surface of the axon.
This creates a challenge for supplying new proteins to axon endings that can be a meter or more away from the soma. Axons contain microtubule-associated motor proteins that transport protein-containing vesicles between the soma and the synapses at the axon terminals. Such transport of molecules towards and away from the soma maintains critical ...
The optimal ratio of axon diameter divided by the total fiber diameter (which includes the myelin) is 0.6. [24] Oligodendrocytes in rat cerebellum stained with antibody to myelin basic protein in red and for DNA in blue. Two oligodendrocyte cell bodies are clearly visible as well as several myelinated axons.
A very important type of glial cell (oligodendrocytes in the central nervous system, and Schwann cells in the peripheral nervous system) generates layers of a fatty substance called myelin that wraps around axons and provides electrical insulation which allows them to transmit action potentials much more rapidly and efficiently. Recent findings ...