| UMN | upper motor neuron |
|---|---|
| UMNL | upper motor neuron lesion |
| UMNS | upper motor neuron syndrome |
| MEP | maximum expiratory pressure; mean effective pressure; mepiridine; mitochondrial encephalopathy; moto... |
| SMA | sequential multiple analysis or analyzer; sequential multichannel autoanalyzer; simultaneous multich... |
| neuron | An excitable cell specialised for the transmission of electrical signals over long distances. Neurons receive input from sensory cells or other neurons and send output to muscles or other neurons. Neurons with sensory input are called sensory neurons, neurons with muscle outputs are called motoneurons, neurons that connect only with other neurons are called interneurons. Neurons connect with each other via synapses. Neurons can be the longest cells known, a single axon can be several metres in length. Although signals are usually sent via action potentials, some neurons are nonspiking. (18 Nov 1997) |
|---|---|
| nonadrenergic, noncholinergic neuron | Autonomic efferent neuron whose transmission is not blocked by blocking adrenergic and cholinergic transmission. Nitric oxide may be the transmitter in some cases. (05 Mar 2000) |
| nonspiking neuron | <physiology> A neuron that can convey information without generating action potentials. As passive electrical potentials are attenuated over distances greater than the space constant for a neuron (typically 1mm), this implies that most nonspiking neurons are involved in signalling over relatively short distances. Typical examples are invertebrate stretch receptors and interneurons in the central nervous system. (12 Mar 1998) |
| intercalary neuron | A neuron interposed between and connecting two other neuron's. Synonym: intercalary neuron. (05 Mar 2000) |
| internuncial neuron | A neuron interposed between and connecting two other neuron's. Synonym: intercalary neuron. (05 Mar 2000) |
| facilitator neuron | <physiology> A neuron whose firing enhances the effect of a second neuron on a third. This allows the effects of neuronal activity to be modulated. (18 Nov 1997) |
| unipolar neuron | A neuron 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 fibre, and a central axon branch that enters into synaptic contact with neuron's in the spinal cord or brainstem. With the single known exception of the neuron's composing the mesencephalic nucleus of the trigeminus, unipolar neuron's are the exclusive neural elements of the sensory ganglia. The lack of dendritic processes of these primary sensory neuron's is only apparent: the dendritic pole of the unipolar neuron is represented by the unmyelinated terminal ramifications of the peripheral axon branch. Synonym: pseudounipolar cell, pseudounipolar neuron, unipolar cell. (05 Mar 2000) |
| asymmetric motor neuropathy | Neuropathy in which the loss of function is more marked in the extremities of one side of the body, old term for diabetic polyradiculopathy. (05 Mar 2000) |
| autonomic motor neurons | (preganglionic neuron's), by contrast, innervate smooth muscle fibres or glands only by the intermediary of a second, peripheral, neuron (postganglionic or ganglionic m. Neuron) located in an autonomic ganglion. See: motor endplate, autonomic nervous system. Synonym: anterior horn cell, motoneuron. (05 Mar 2000) |
| Bender Visual Motor Gestalt test | <psychology> A psychological test used by neurologists and clinical psychologists to measure a person's ability to visually copy a set of geometric designs. It consists of nine geometric designs on cards. The subject is asked to redraw them from memory after each one is presented individually. It is useful for measuring visuospatial and visuomotor coordination to detect brain damage. Synonym: Bender Visual Motor Gestalt test. (14 Aug 2000) |
| gamma motor neurons | The reflex arc consisting of small anterior horn cells and neuroma, their small fibres projecting to the intrafusal bundle producing its contraction, which initiates the afferent impulses that pass through the posterior root to the anterior horn cells, inducing a stretch reflex. Synonym: gamma motor neurons, gamma motor system, Granit's loop. (05 Mar 2000) |
| gamma motor system | The reflex arc consisting of small anterior horn cells and neuroma, their small fibres projecting to the intrafusal bundle producing its contraction, which initiates the afferent impulses that pass through the posterior root to the anterior horn cells, inducing a stretch reflex. Synonym: gamma motor neurons, gamma motor system, Granit's loop. (05 Mar 2000) |
| major motor seizure | A grand mal seizure or other convulsive seizure. (05 Mar 2000) |
| minor motor seizure | Old term for nonconvulsive seizure seen in patients with secondary generalised epilepsies. (05 Mar 2000) |
| motor | <neurology, physiology> A muscle, nerve or centre that effects or produces movement. (18 Nov 1997) |