Also found in: Dictionary, Thesaurus, Encyclopedia.
association neuronInterneuron, internuncial neuron A nerve cell confined to the CNS, which conveys impulses in an arc from sensory to motor neurons
McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.
neuron(noo'ron?) [Gr. neuron, nerve, sinew]
A nerve cell, the structural and functional unit of the nervous system. A neuron consists of a cell body (perikaryon) and its processes, an axon and one or more dendrites. Neurons function in the initiation and conduction of impulses. They transmit impulses to other neurons or cells by releasing neurotransmitters at synapses. Alternatively, a neuron may release neurohormones into the bloodstream. Synonym: nerve cell See: illustrationneuronal (noor''on-al), adjective
A neuron that conducts sensory impulses toward the brain or spinal cord.Synonym: sensory neuron
A neuron that mediates impulses between a sensory and a motor neuron.
1. A neuron that bears two processes.
2. A neuron of the retina that receives impulses from the rods and cones and transmits them to a ganglion neuron. See: retina for illus.
A neuron confined entirely to the central nervous system.
A neuron whose axon crosses to the opposite side of the brain or spinal cord.
A neuron whose axon carries motor impulses away from the brain or spinal cord.
gamma motor neuron
A small nerve originating in the anterior horns of the spinal cord that transmits impulses through type A gamma fibers to intrafusal fibers of the muscle spindle for muscle control.
A neuron of the retina that receives impulses from bipolar neurons. Axons of ganglion neurons converge at the optic disk to form the optic nerve.See: retina for illus.
lower motor neuron
A peripheral motor neuron that originates in the ventral horns of the gray matter of the spinal cord and terminates in skeletal muscles. Lesions of these neurons produce flaccid paralysis of the muscles they innervate. Synonym: lower motoneuron
Any of a group of neurons that become active both when an animal moves in a certain way and when the animal observes others performing the same action. Learning by simulation or imitation is thought to be a function of the system of mirror neurons in the brain.
A neuron that carries impulses from the central nervous system either to muscle tissue to stimulate contraction or to glandular tissue to stimulate secretion.
A neuron with one axon and many dendrites.
A neuron whose process constitutes a part of the peripheral nervous system (cranial, spinal, or autonomic nerves).
peripheral motor neuron
A motor neuron that transmits impulses to skeletal muscle. Synonym: peripheral motoneuron
A neuron of the autonomic nervous system whose cell body lies in an autonomic ganglion and whose axon terminates in a visceral effector (smooth or cardiac muscle or glands).
A neuron of the autonomic nervous system whose cell body lies in the central nervous system and whose axon terminates in a peripheral ganglion, synapsing with postganglionic neurons.
sensory neuronAfferent neuron.
A nerve cell that uses serotonin as its neurotransmitter.
A neuron whose cell body bears one process.
upper motor neuron
A motor neuron (actually an interneuron) found completely within the central nervous system that synapses with or regulates the actions of lower motor neurons in the spinal cord and cranial nerves. Lesions of these neurons produce spastic paralysis in the muscles they innervate. Synonym: upper motoneuron
Medical Dictionary, © 2009 Farlex and Partners