neuron


neuron
neuronal /noor"euh nl, nyoor"-, noo rohn"l, nyoo-/, adj.
/noor"on, nyoor"-/, n.
Cell Biol. a specialized, impulse-conducting cell that is the functional unit of the nervous system, consisting of the cell body and its processes, the axon and dendrites.
Also called nerve cell. Also, esp. Brit., neurone /noor"ohn, nyoor"-/. Cf. synapse.
[1880-85; < Gk neûron sinew, cord, nerve]

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Any of the cells of the nervous system.

Sensory neurons relay information from sense organs, motor neurons carry impulses to muscles and glands, and interneurons transmit impulses between sensory and motor neurons. A typical neuron consists of dendrites (fibres that receive stimuli and conduct them inward), a cell body (a nucleated body that receives input from dendrites), and an axon (a fibre that relays the nerve impulse from the cell body outward to its terminals, the synaptic knobs). Both axons and dendrites may be referred to as nerve fibres. Impulses are conducted by neurotransmitter chemicals released by the axon's synaptic knobs across the synapses (junctions between neurons or between a neuron and an effector cell, such as a muscle cell) or, in some cases, pass directly from one neuron to the next. Most neurons are insulated by a myelin sheath formed by cells (Schwann cells) surrounding the axons. Bundles of fibres from neurons held together by connective tissue form nerves.

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also called  nerve cell 
  basic cell of the nervous system in vertebrates and most invertebrates from the level of the cnidarians (cnidarian) (e.g., corals, jellyfish) upward. A typical neuron has a cell body containing a nucleus and two or more long fibres. Impulses are carried along one or more of these fibres, called dendrites, to the cell body; in higher nervous systems, only one fibre, the axon, carries the impulse away from the cell body. Bundles of fibres from neurons are held together by connective tissue and form nerves. Some nerves in large vertebrates are several feet long. A sensory neuron transmits impulses from a receptor, such as those in the eye (eye, human) or ear (ear, human), to a more central location in the nervous system, such as the spinal cord or brain. A motor neuron transmits impulses from a central area of the nervous system to an effector, such as a muscle.

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Universalium. 2010.

Look at other dictionaries:

  • neuron — NEURÓN, neuroni, s.m. Element structural şi funcţional de bază al sistemului nervos compus dintr un corp celular protoplasmatic, care conţine un nucleu, şi din prelungiri protoplasmatice; neurocit. [pr.: ne u ] – Din fr. neurone. Trimis de… …   Dicționar Român

  • neuron — (n.) a nerve cell with appendages, 1891, from Ger. Neuron, from Gk. neuron (see NEURO (Cf. neuro )). Used earlier (1884) for the spinal cord and brain …   Etymology dictionary

  • neuron — UK [ˈnjʊərɒn] / US [ˈnʊˌrɑn] or neurone UK / US noun [countable] Word forms neuron : singular neuron plural neurons Word forms neurone : singular neurone plural neurones medical a cell that sends messages to your brain and receives messages from… …   English dictionary

  • neuron — (also neurone) ► NOUN ▪ a specialized cell transmitting nerve impulses. DERIVATIVES neuronal adjective. USAGE In scientific sources the standard spelling is neuron. The spelling neurone is found only in non technical sources. ORIGIN Greek neuron …   English terms dictionary

  • neuron — neùrōn m <G neuróna> DEFINICIJA anat. živčana stanica ETIMOLOGIJA grč. neȗron …   Hrvatski jezični portal

  • neuron — [noo′rōn΄, nyo͞o′rōn΄noor′än΄, nyoor′än] n. [ModL < Gr neuron, NERVE] the structural and functional unit of the nervous system, consisting of the nerve cell body and all its processes, including an axon and one or more dendrites: also neurone… …   English World dictionary

  • Neuron — Neu ron, n.; pl. {Neura}. [NL., from Gr. ney^ron nerve.] (Anat.) 1. The brain and spinal cord; the cerebro spinal axis; myelencephalon. [obsolete] B. G. Wilder. [1913 Webster] 2. (Cell Biology) The characteristic specialized cell that is part of… …   The Collaborative International Dictionary of English

  • neuron — neuron. См. нервная клетка. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) …   Молекулярная биология и генетика. Толковый словарь.

  • Neuron — (v. gr.), Nerv. Neuronŏsos, Nervenkrankheit. Neuropăthie, Nervenleiden …   Pierer's Universal-Lexikon

  • Neurōn — (griech), nach Waldeyer Bezeichnung der unser Nervensystem bildenden Einheiten. Der N. besteht aus der Ganglienzelle, ihren Cytoplasmafortsätzen (Dendriten) und dem Achsenzylinderfortsatz (Neuriten). Jeder Achsenzylinder gehört einem N. zu. Die… …   Meyers Großes Konversations-Lexikon

  • Neuron — Neurōn (grch.), Nerv; nach Waldeyer die zuerst von Forel aufgestellte anatom. und physiol. Einheit des Nervensystems, bestehend aus Nervenzelle, zugehöriger Nervenfaser und deren Endverästelungen [Tafel: Nervensystem II, 15 u. 16.]. Die einzelnen …   Kleines Konversations-Lexikon


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