1. The morphological and functional unit of the nervous system, consisting of the nerve cell body, the dendrites, and the axon.nerve cell, neurocyte, neurone; 2. Obsolete term for axon. [G. neuron, a nerve]
autonomic motor n. See motor n.
bipolar n. a n. that has two processes arising from opposite poles of the cell body.
gamma motor n.'s gamma loop
ganglionic motor n. See motor n.
Golgi type I n. nerve cells whose long axons leave the gray matter of which they form a part.
Golgi type II n. nerve cells with short axons which ramify in the gray matter.
intercalary n. internuncial n
internuncial n. a n. interposed between and connecting two other n.'s.intercalary n;
lower motor n. clinical term used to indicate the final motor n.'s that innervate the skeletal muscles; distinguished from upper motor n.'s of the motor cortex that contribute to the pyramidal or corticospinal tract. See also motor n.
motor n. a nerve cell in the spinal cord, rhombencephalon, or mesencephalon characterized by having an axon that leaves the central nervous system to establish a functional connection with an effector (muscle or glandular) tissue; somatic motor n.'s directly synapse with striated muscle fibers by motor endplates; visceral motor n.'s or autonomic motor n.'s (preganglionic m. n.'s), by contrast, innervate smooth muscle fibers or glands only by the intermediary of a second, peripheral, n. (postganglionic or ganglionic m. n.) located in an autonomic ganglion. See also motor endplate, autonomic nervous system.anterior horn cell, motoneuron;
multipolar n. a n. with several processes, usually an axon and three or more dendrites.
NANC n. abbreviation for non-adrenergic, non-cholinergic n.
non-adrenergic, non-cholinergic n. (NANC n.) autonomic efferent neuron whose transmission is not blocked by blocking adrenergic and cholinergic transmission. Nitric oxide may be the transmitter in some cases.
polymorphic n. occurring in many shapes. See also multipolar cell.
postganglionic motor n. See motor n.
preganglionic motor n. See motor n.
pseudounipolar n. unipolar n
sensory n. a n. conveying information originating from sensory receptors or nerve endings; afferent neuron, may be general or special sensory.
somatic motor n. See motor n.
unipolar n. a n. whose cell body emits a single axonal process resulting from the fusion of two polar processes during development; at a variable distance from the cell body, the process divides into a peripheral axon branch extending outward as a peripheral afferent (sensory) nerve fiber, and a central axon branch that enters into synaptic contact with n.'s in the spinal cord or brainstem. With the single known exception of the n.'s composing the mesencephalic nucleus of the trigeminus, unipolar n.'s are the exclusive neural elements of the sensory ganglia. The lack of dendritic processes of these primary sensory n.'s is only apparent: the dendritic pole of the unipolar n. is represented by the unmyelinated terminal ramifications of the peripheral axon branch.pseudounipolar cell, pseudounipolar n., unipolar cell;
upper motor n. clinical term indicating those n.'s of the motor cortex that contribute to the formation of the pyramidal or corticospinal and corticobulbar tracts, as distinguished from the lower motor n.'s innervating the skeletal muscles. Although not motor n.'s in the strict sense, these cortical n.'s became colloquially classified as motor n.'s because their stimulation produces movement and their destruction causes severe disorders of movement. See also motor n., motor cortex.
visceral motor n. See motor n.
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