| 释义 |
myelin
my·e·lin M0508100 (mī′ə-lĭn) also my·e·line (-lĭn, -lēn′)n. A white fatty material, composed chiefly of lipids and lipoproteins, that encloses certain axons and nerve fibers. Also called medulla.
my′e·lin′ic adj.myelin (ˈmaɪɪlɪn) or myelinen (Anatomy) a white tissue forming an insulating sheath (myelin sheath) around certain nerve fibres. Damage to the myelin sheath causes neurological disease, as in multiple sclerosis ˌmyeˈlinic adjmy•e•lin (ˈmaɪ ə lɪn)
n. a soft, white, fatty material in the membrane of Schwann cells and certain neuroglial cells of the nervous system: the substance of the myelin sheath. [1865–70] my`e•lin′ic, adj. my·e·lin (mī′ə-lĭn) A whitish, fatty substance that forms a sheath around many nerve fibers. Myelin insulates the nerves and permits nerve impulses to travel more rapidly. The white matter of the brain is composed of nerve fibers covered in myelin.myelinThe fatty white substance forming an insulating sheath around many nerve fibers.Thesaurus| Noun | 1. |  myelin - a white fatty substance that forms a medullary sheath around the axis cylinder of some nerve fibersmedulla, myelinemedullary sheath, myelin sheath - a layer of myelin encasing (and insulating) the axons of medullated nerve fibersfat - a soft greasy substance occurring in organic tissue and consisting of a mixture of lipids (mostly triglycerides); "pizza has too much fat" |
Translationsmyelin
myelin, myeline a white tissue forming an insulating sheath (myelin sheath) around certain nerve fibres. Damage to the myelin sheath causes neurological disease, as in multiple sclerosis myelin[′mī·ə·lən] (neuroscience) A soft, white fatty substance that forms a sheath around certain nerve fibers. myelin
myelin [mi´ĕ-lin] the lipid substance forming a sheath (the sheath" >myelin sheath) around the axons of certain nerve fibers; it is an electrical insulator that serves to speed the conduction of nerve impulses in these nerve fibers, which are called myelinated or medullated fibers. adj., adj myelin´ic.
Myelinated nerve fibers occur predominantly in the cranial and spinal nerves and compose the white matter of the brain and spinal cord. Unmyelinated fibers are abundant in the autonomic nervous system. The term gray matter refers to areas in the nervous system in which the nerve fibers are unmyelinated. In unmyelinated nerves impulses are conducted by the propagation of the action potential along the membrane of the axon. In myelinated nerves impulses are transmitted by an entirely different process, called saltatory conduction, in which the impulse jumps from one node of ranvier to the next. Impulses in myelinated nerves are transmitted hundreds of times faster and require much less energy than in unmyelinated nerves. Structure of a typical myelin sheath. From Applegate, 2000.my·e·lin (mī'ĕ-lin), 1. The lipoproteinaceous material, composed of regularly alternating membranes of lipid lamellae (for example, cholesterol, phospholipids, sphingolipids, and phosphatidates) and protein, of the myelin sheath. 2. Droplets of lipid formed during autolysis and postmortem decomposition. myelin (mī′ə-lĭn) also myeline (-lĭn, -lēn′)n. A white fatty material, composed chiefly of lipids and lipoproteins, that encloses certain axons and nerve fibers. Also called medulla.
my′e·lin′ic adj.my·e·lin (mī'ĕ-lin) 1. The lipoproteinaceous material of the myelin sheath, composed of alternating membranes of lipid and protein. 2. Droplets of lipid formed during autolysis and postmortem decomposition. myelin The fatty, white material forming a sheath around most nerve fibres and acting as an insulator. See also DEMYELINATION.myelin a white phospholipid. See MYELIN SHEATH.MyelinA whitish fatty substance that acts like an electrical insulator around certain nerves in the peripheral nervous system. It is thought that the loss of the myelin surrounding the vestibular nerves may influence the development of Ménière's disease.Mentioned in: Adrenoleukodystrophy, Charcot Marie Tooth Disease, Guillain-Barré Syndrome, Ménière's Disease, Multiple Sclerosis, Paralysis, Peripheral Neuropathy, Phenylketonuriamy·e·lin (mī'ĕ-lin) Lipoproteinaceous material, composed of regularly alternating membranes of lipid lamellae (e.g., cholesterol, phospholipids, sphingolipids, and phosphatidates) and protein, of the myelin sheath. Patient discussion about myelinQ. What is Myelin? A. As part of the nervous system, myelin lines nerve fibers to protect and insulate neurons. Myelin aids in the quick and accurate transmission of electrical current carrying data from one nerve cell to the next. When myelin becomes damaged, the process involves numerous health conditions, including multiple sclerosis.
Dysfunction in the myelin of nerve fibers causes the interruption of smooth delivery of information. Either nerve impulses can be slowed, such that we can't pull our hand away in time to avoid being burned, or mixed up, so we aren't able to determine if a pan is hot in the first place. This is akin to a pet chewing on a wire, causing the device to dysfunction. When problems arise in nerves of the PNS, neuropathy might result, and when injury affects the nerves of the CNS, multiple sclerosis is often diagnosed.
More discussions about myelinmyelin
Related to myelin: demyelination, Myelin basic proteinSynonyms for myelinnoun a white fatty substance that forms a medullary sheath around the axis cylinder of some nerve fibersSynonymsRelated Words- medullary sheath
- myelin sheath
- fat
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