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the kneelsit GLOSSARY Pg.8

medical and general terms relating to posture, sitting, musculoskeletal and back problems
ABBREVIATIONS:- Gr.= Greek; L.= Latin; Fr.= French; Ger = German; NA = Nomina Anatomica

N.

nervous system. A system of extremely delicate nerve cells, elaborately interlaced with each other. Made up collectively of the brain, cranial nerves, spinal cord, spinal nerves, autonomic ganglia, ganglionated trunks and nerves, maintaining the vital function of reception and response to stimuli. The nervous system regulates and coordinates body activities and brings about responses by which the body adjusts to changes of environment, either external or internal. These changes constitute stimuli that initiate impulses in receptors or sense organs. The principal organs of this group are the eye, ear, the organs of taste smell, and sensory receptors located in the skin, joints, muscles, and various parts of the body. The nervous system consists of two divisions: the central nervous system, which includes the brain and spinal cord; and the peripheral nervous system, which includes all the other neural elements. SEE: autonomic nervous system; central nervous system; parasympathetic nervous system; sympathetic nervous system.
autonomic nervous system. The part of the nervous system that is concerned with control of involuntary bodily functions. It regulates the function of glands, esp. the salivary, gastric, and sweat glands, and the adrenal medulla; smooth muscle tissue; and the heart. The autonomic nervous system may act on these tissues to reduce or slow activity or to initiate their function.
It is divided into the sympathetic or thoracolumbar system and the parasympathetic or craniosacral system. The sympathetic system is made up of the paired ganglionated sympathetic trunk; its connections (rami communicantes) with the thoracic and lumbar parts of the spinal nerve; the large and small splanchnic nerves; and certain ganglia in the abdomen (e.g., the mesenteric ganglia). The parasympathetic system consists of certain fibers of some cranial nerves, such as the motor fibers of the vagus, and of other fibers connected with the sacral part of the spinal cord.
FUNC: Stimulating sympathetic fibers usually produces vasoconstriction in the part supplied, general rise in blood pressure, erection of the hairs, gooseflesh, pupillary dilation, secretion of small quantities of thick saliva, depression of gastrointestinal activity, and acceleration of the heart. In general, these activities occur in emergencies such as fright and are associated with the expenditure of energy as a response to the need to flee, fight, or to be frightened. They are mediated through the release of a transmitter agent, norepinephrine.
Stimulating parasympathetic nerves generally produces vasodilation of the part supplied, general fall in the blood pressure, con traction of the pupil, copious secretion of thin saliva, increased gastrointestinal activity, and slowing of the heart. SEE: nervous system.

nervous tissue. Tissue that makes up the nervous system. Includes the nervous elements proper (neurons) and the interstitial tissue (neuroglia, neurilemma cells, and satellite cells).

neural (nural) [L. neuralis]. Pert. to nerves or connected with the nervous system.

neural crest. A band of cells extending longitudinally along the neural tube of an embryo from which cells forming cranial, spinal, and autonomic ganglia arise. They also give rise to cells (ectomesenchyme) that migrate into the forming facial region and become odontoblasts, which form the dentin of the tooth.

neuralgia (nu-ralge-a) [Gr. neuron, nerve, sinew, + algos, pain]. Severe sharp pain along the course of a nerve. SYN: neurodynia. SEE: sciatica.
ETIOL: Pressure on nerve trunks, faulty nerve nutrition, toxins, neuritis. Usually no morphologic changes can be detected.
n.. degenerative. Neuralgia caused by degenerative changes in the nerves or nerve cells; occurs in the elderly. n., facial. N., trigeminal,
n., facialls Vera. N., geniculate,
n., Fothergill's. N., trigeminal,
n., geniculate. Neuralgia characterized by pain over all or any part supplied by sensory fibers of facial nerve. Pain may be deep in facial muscles, within the ear, or in pharynx. SYN: n., Hunt's.
n., Hunt's. N., geniculate.
n., idiopathic. Neuralgia without structural lesion or pressure from a lesion.

neural spine. Spinous vertebral process.

neural tube. Tube formed from fusion of the neural folds from which the brain and spinal cord arise.

neurasthenia (nuras-thene-a) [+ astheneia, weakness]. A term previously used for persons with unexplained chronic fatigue and lassitude. Accompanying these symptoms were usually nervousness, irritability, anxiety, depression, headache, insomnia, and sexual disorders. Those individuals are now diagnosed according to their total condition, such as some form of psychiatric illness, esp. anxiety neurosis or tension state.

neurasthenic (nu-ras-thenik). 1. Individual suffering from neurasthenia. 2. Suffering from or concerning neurasthenia.

neurilernma (nuri'-lemma) [" + lemma, husk]. A thin membranous sheath enveloping a nerve fiber. SYN: neurolemma; sheath of Schwann. SEE: nerve fiber.

neurilemmitis (nuri-lem-mitis) [+ itis, inflammation]. Inflamed condition of a neurilemma.

neurilemmosarcoma (nuri-lemo-sar-koma). A malignant neurilemoma.

neurilemoma, neurilemmoma (nuri-lem-oma) [" + eilema, tight sheath, + oma, tumor]. A firm, encapsulated fibrillar tumor of peripheral nerves. SYN: neurinoma; neurofibroma, peripheral glioma, schwannoma

Neurimotility (nuri-mo-tili-te) [+ motilus, moving. ] Nervimotility,

neurimotor [" + L. motor, a mover]. Concerning a motor nerve. neuroarthritism (nuro-arthri-tizm) [ + arthron, joint, + -ismos, condition]. Tendency toward contraction of nervous and gouty disorders.

neuroarthropathy (nuro-ar-thropath-e) [ " + pathos, disease, suffering). Disease of a joint combined with disease of the central nervous system.

neurocanal (nuro-ka-nal) [ + L, canalis, passage]. The central canal of the spinal cord,

neurocele (nu'ro-sel) [" + koilia, cavity]. Ventricles and cavities in the cerebrospinal axis.

neurocentral (nuro-sentrall) [" + kentron, center]. Pert. to the centrum of a vertebra and the neural arch.

neurocentrum (nuro-centrum). The body of a vertebra.

neurocoele (nuro-sel) [ + koilia, cavity]. System of cavities in cerebrospinal axis. SYN: neurocele.

neurocyte (nuro-sit) [ + kytos, cell]. A nerve cell. SYN: neuron.

neurocytolysis (nuro-si-toli-sis) [ + kytos, cell, + lysis, dissolution]. Dissolution or destruction of nerve cells.

neurocytoma (nuro-si-toma) [ + oma, tumor]. A tumor formed of cells, usually ganglionic, of nervous origin. SEE: neuroma

neurohumor (nu-ro-humor). A chemical substance liberated at a nerve ending that excites or activates an adjacent structure (neuron or muscle fiber). Ex.: acetylcholine, epinephrine, norepinephrine. These substances are essential for transmission of impulses across synapses or myoneural junctions.

neurology (nu-rolo-je) [" + logos, word, reason]. The branch of medicine that deals with the nervous system and its diseases. SEE: psychiatry and neurology, words pert. to.
n., clinical The branch of medicine that is concerned with study and treatment of diseases of the nervous system.

neuroma (nu-roma) [ + oma, tumor]. Former term for any type of tumor composed of nerve cells. New growth of nerves is now categorized with respect to the specific portion of the nerve involved. SEE: ganglianeuroma; neurilemoma.
n., acoustic. A benign tumor of the eighth cranial nerve. The symptoms may include hearing loss, balance disturbances, pain, headache, and tinnitis.
n., amputation. Neuroma occurring on a stump after amputation.
n., cystic. Neuroma with cystic formations.
n., false. Tumor arising from connective tissue of nerves, including the myelin sheath. SYN: neurofibroma; pseudoneuroma .
n., ganglionated. Neuroma composed of true nerve cells.
n., multiple. Neurofibromatosis.
n., myelinic. Neuroma composed of medullated nerve fibers.

neuromuscular (nuro-musku-lar) [" + L. musculus, a muscle]. Concerning both nerves and muscles.

neurornyasthenia (nuro-mias-thene-a) [" + mys, muscle, + astheneia, weakness]. Muscular weakness usually due to an emotional disorder.

neuromyelitis (nuro-mi-el-itis) [ + myelos, marrow, + itis, inflammation]. Inflammation of nerves and the spinal cord.

neurormyopathic (nuro-mio-pathik) [ + mys, muscle, + pathos, disease, suffering]. Pert. to pathological conditions involving both muscles and nerves.

neurormyositis (nuro-mio-sitis) [" + itis, inflammation]. Neuritis complicated by inflammation of muscles that come in contact with affected nerves.

neuron (nuron) [Gr. neuron, nerve, sinew]. A nerve cell, the structural and functional unit of the nervous system. A neuron consists of a cell body or perikaryon and its processes, an axon, and one or more dendrites. Neurons function in initiation and conduction of impulses. SEE: nerve; nervous system.
n., afferent. Neuron that conducts impulses toward the brain or spinal cord.
n., associative. Neuron that mediates impulses between a sensory and a motor neuron.
n., bipolar. Neuron that bears two processes.
n., central. Neuron confined entirely to central nervous system.
n., commissural. Neuron whose axon crosses to opposite side of the brain or spinal cord.
n., efferent. Neuron that conducts impulses away from the brain or spinal cord.
n., motor. Neuron that conveys impulses initiating muscle contraction.
n., motor, lower. Neuron whose cell body lies in anterior gray column of spinal cord. Its axon innervates striated muscle fibers.
n., motor, upper. Neuron whose cell body lies in motor area of cerebral cortex. Its axon passes down spinal cord and synapses with lower motor neurons.
n., multipolar. Neuron with one axon and many dendrites.
n., peripheral. Neuron whose process constitutes a part of the peripheral nervous system (cranial, spinal, or sympathetic nerves).
n., postganglionic. Neuron whose body lies in an autonomic ganglion and whose axon terminates in an effector organ (smooth or cardiac muscle or glands).
n., preganglionic. Neuron of autonomic nervous system whose cell body lies in central nervous system and axon terminates in peripheral ganglia.
n., sensory. An afferent neuron that conveys impulses that give rise to sensations.

nuclear magnetic resonance imaging. ABBR: NMRI. When certain atomic nuclei with an odd number of protons or neutrons or both are subjected to a strong magnetic field, they absorb and re-emit electromagnetic energy. Analysis of the net magnetization vector's deflection by application of a radiofrequency pulse provides image information. This technique is valuable in providing images of the heart, large blood vessels, brain, and soft tissues. It does not involve exposure to ionizing radiation, nor is there need to inject a contrast medium. Nevertheless, it is expensive and necessitates keeping the patient immobile for a lengthy period. It is contraindicated in patients with cardiac pacemakers or ferromagnetic aneurysmal clips in place. SYN: magnetic resonance imaging.

nuclear medicine. That branch of medicine concerned with the diagnostic, therapeutic, and investigative use of radionuclides, q.v.