neuron, neurone

The functional unit of the nervous system. A neurone is a single cell having a very long, fibre-like extension, called an axon, and one or many short extensions called dendrites. The axon may be 100,000 times as long as the diameter of the cell body-some are as long as 1 m. Nerve impulses are moving zones of electrical depolarization and these travel outwards along the axon from the cell body. Incoming impulses travel to the cell body along the dendrites. Neurones interconnect with each other at specialized junctions called SYNAPSES, situated mainly between the end of an axon of one neurone and the cell body or the dendrites of another. Many neurones receive as many as 15,000 synapses, some more. Most synapses are interneurones connecting with other nerve cells, rather than with muscles or glands.

Fig. 228 Neuron . A vertebrate motor nerve cell.

neuron, neurone

nerve cell

the structural unit of the nervous system, usually consisting of the cell body and cytoplasmic extensions. Long single extensions are known as AXONS and these carry impulses from the cell body to other nerve cells or effectors. Short multiple extensions known as DENDRITES receive impulses. Axons may be myelinated (with MYELIN SHEATHS) or nonmyelinated, but in the former the transmission of impulses is quicker as action potentials jump from one node of Ranvier to another.

单词	neuron, neurone
释义	DictionarySeenerve cellSee nerve cell See nerve cell neuron, neurone neuron, neurone The functional unit of the nervous system. A neurone is a single cell having a very long, fibre-like extension, called an axon, and one or many short extensions called dendrites. The axon may be 100,000 times as long as the diameter of the cell body-some are as long as 1 m. Nerve impulses are moving zones of electrical depolarization and these travel outwards along the axon from the cell body. Incoming impulses travel to the cell body along the dendrites. Neurones interconnect with each other at specialized junctions called SYNAPSES, situated mainly between the end of an axon of one neurone and the cell body or the dendrites of another. Many neurones receive as many as 15,000 synapses, some more. Most synapses are interneurones connecting with other nerve cells, rather than with muscles or glands. Fig. 228 Neuron . A vertebrate motor nerve cell. neuron, neurone or nerve cell the structural unit of the nervous system, usually consisting of the cell body and cytoplasmic extensions. Long single extensions are known as AXONS and these carry impulses from the cell body to other nerve cells or effectors. Short multiple extensions known as DENDRITES receive impulses. Axons may be myelinated (with MYELIN SHEATHS) or nonmyelinated, but in the former the transmission of impulses is quicker as action potentials jump from one node of Ranvier to another.
随便看	asian pacific interdisciplinary research in accounting conference asian pacific internet backbone asian & pacific islander american health forum asian pacific islander caucus asian/pacific islander coalition on hiv/aids asian pacific islander community aids project asian pacific islander faculty staff association asian/pacific islander/native american employment program asian pacific islander queer sisters asian pacific islanders for human rights asian & pacific islander tobacco education network asian/pacific islander youth violence prevention center asian pacific journal of cancer prevention asian pacific journal of tropical biomedicine asian-pacific law and policy journal asian-pacific le mans series asian-pacific operations research society asian pacific organization for cancer prevention asian-pacific parliamentarians' union asian pacific partners for empowerment and leadership asian pacific postal union asian-pacific regional international astronomical union meeting asian pacific society of atherosclerosis and vascular diseases asian pacific society of nephrology asian-pacific society of nuclear cardiology