Sensory neuron

Sensory neuron

Sensory neurons are neurons that are activated by sensory input (vision, touch, hearing, etc.), and send projections into the central nervous system that convey sensory information to the brain or spinal cord. Unlike neurons of the central nervous system, whose inputs come from other neurons, sensory neurons are activated by physical modalities such as light, sound, temperature, chemical stimulation, etc.

In complex organisms, sensory neurons relay their information to the central nervous system or in less complex organisms, such as the hydra, directly to motor neurons and sensory neurons also transmit information to the brain, where it can be further processed and acted upon. For example, olfactory sensory neurons make synapses with neurons of the olfactory bulb, where the sense of olfaction (smell) is processed.

At the molecular level, sensory receptors located on the cell membrane of sensory neurons are responsible for the conversion of stimuli into electrical impulses. The type of receptor employed by a given sensory neuron determines the type of stimulus it will be sensitive to. For example, neurons containing mechanoreceptors are sensitive to tactile stimuli, while olfactory receptors make a cell sensitive to odors.

Fiber types

Peripheral nerve fibers can be classified based on axonal conduction velocity, mylenation, fiber size etc. For example, there are slow-conducting unmyelinated C fibers and faster-conducting myelinated Aδ fibers.

ee also

* Sensory nerves
* Afferent nerve
* Pseudounipolar neuron
* Efferent nerve

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Look at other dictionaries:

  • sensory neuron — n a neuron that transmits nerve impulses from a sense organ towards the central nervous system compare INTERNEURON, MOTOR NEURON * * * any neuron with a sensory function; an afferent neuron conveying sensory impulses. Cf. primary sensory n. and… …   Medical dictionary

  • sensory neuron — n. a type of neuron that carries impulses from a sense organ to the brain or spinal cord …   English World dictionary

  • sensory neuron — noun a neuron conducting impulses inwards to the brain or spinal cord • Syn: ↑afferent neuron • Hypernyms: ↑nerve cell, ↑neuron • Part Holonyms: ↑sensory nerve, ↑afferent nerve, ↑afferent …   Useful english dictionary

  • sensory neuron — (1) A neuron that receives input from sensory cells. (2) Sensory cells such as cutaneous mechanoreceptors and muscle receptors …   Dictionary of molecular biology

  • sensory neuron — A neuron that acts as a receptor or receives excitation directly from a receptor that is not a neuron; an axonic connection usually to the central nervous system …   Dictionary of invertebrate zoology

  • sensory neuron — Biol. a nerve cell that conducts impulses from a sense organ to the central nervous system. * * * …   Universalium

  • sensory neuron — sen′sory neu ron (or nerve ) n. phl a nerve cell that conducts impulses from the periphery of the body to the central nervous system …   From formal English to slang

  • primary sensory neuron — a sensory neuron that is the first in an afferent pathway, beginning at the receptor and ending at a synapse with a secondary sensory neuron, often within a nucleus of the central nervous system. One common type is the pseudounipolar neuron …   Medical dictionary

  • secondary sensory neuron — a sensory neuron that is the second in an afferent pathway, being stimulated at a synapse by a primary sensory neuron and often extending some distance into the central nervous system …   Medical dictionary

  • peripheral sensory neuron — in a reflex arc, a sensory neuron whose fibers end at synapses with interneurons. Cf. peripheral motoneuron …   Medical dictionary

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