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ansenUK
ans (ænz) pl nthings that might have happened, but which did notThesaurusNoun | 1. | ANS - the part of the nervous system of vertebrates that controls involuntary actions of the smooth muscles and heart and glandsautonomic nervous systemautonomic ganglion - any of the ganglia of the autonomic system whose unmyelinated fibers innervate the internal organsnervous system, systema nervosum - the sensory and control apparatus consisting of a network of nerve cellsneural structure - a structure that is part of the nervous systemsympathetic nervous system - originates in the thoracic regions of the spinal cord; opposes physiological effects of the parasympathetic: reduces digestive secretions; speeds the heart; contracts blood vesselsparasympathetic, parasympathetic nervous system - originates in the brain stem and lower part of the spinal cord; opposes physiological effects of the sympathetic nervous system: stimulates digestive secretions; slows the heart; constricts the pupils; dilates blood vessels | IdiomsSeeanANS
ANS Abbrev. for Astronomical Netherlands Satellite.ANSAmerican National StandardANS(ANS Communications, Inc, Purchase, NY) An ISP, Internet backbone and provider of private data network services, founded in 1990 as Advanced Network & Services, Inc., by IBM, MCI and Merit (consortium of Michigan universities). The original ANS was formed as a non-profit network services provider for NFSnet, but later added commercial customers through its for-profit ANS CO+RE (COmmercial REsearch) subsidiary.
In 1995, ANS CO+RE was acquired by AOL and changed its name to ANS Communications. The non-profit arm of Advanced Network & Services (www.advanced.org) moved into Internet-based education. In 1997, WorldCom acquired ANS from AOL and completely absorbed it into its UUNET Internet subsidiary. In 2004, WorldCom emerged from bankruptcy as MCI.ANS
ANSAbbreviation for autonomic nervous system.ANS American Nimodipine Study. A clinical trial that assessed nimodipine’s effect on mortality in post-acute stroke patients. Conclusions Nimodipine has no effect on patients at 48 hours, but may be beneficial at 18 hours.ANS Abbreviation for autonomic nervous system. autonomic nervous system, ANS AUTONOMIC NERVOUS SYSTEMThe parts of the nervous system that control unconscious, involuntary, and visceral body functions. The autonomic nervous system reflexively balances the body's smooth muscle tone, blood pressure, temperature, fluid composition, state of digestion, metabolic activity, and sexual activation. In the central nervous system (CNS), the activities of the autonomic nervous system (ANS) are coordinated in the brainstem (especially in the nucleus of the tractus solitarius) and in the hypothalamus. In the peripheral nervous system (PNS), the ANS comprises the visceral motor axons, the visceral sensory axons, and the enteric nervous system (a neural net within the walls of the gastrointestinal tract). Compared to peripheral somatic axons, the peripheral autonomic axons tend to be small (less than 3 µm in diameter), slowly conducting, and sparsely myelinated. The autonomic motor circuits also differ from somatic motor pathways. Peripheral somatic motor pathways, i.e., the circuitry sending signals to skeletal muscles, are only one axon long; axons of somatic motor neurons in the spinal cord and brainstem synapse directly on the effector cell, a muscle cell. In contrast, peripheral autonomic motor pathways are two axons long. First, an axon (a preganglionic axon) of a visceral motor neuron in the spinal cord or brainstem synapses on a neuron in a peripheral ganglion. Second, the axon (a postganglionic axon) of the ganglion neuron synapses on the effector cell, a smooth muscle cell, a cardiac muscle cell, or a secretory cell. This autonomic motor circuitry is further subdivided into two parallel subsystems; the sympathetic and the parasympathetic. The subsystems differ in two major ways: 1. In the sympathetic system, the central (preganglionic) neurons are located only in the thoracic and lumbar segments of the spinal cord; in the parasympathetic system, the central neurons are located only in the brainstem and in a short segment of the caudal end of the spinal cord. 2. In the sympathetic system, norepinephrine is the characteristic neurotransmitter of the postganglionic axons; in the parasympathetic system, acetylcholine is the characteristic neurotransmitter of the postganglionic axons. In both the sympathetic and parasympathetic systems, the characteristic neurotransmitter of the preganglionic axons is acetylcholine.Besides their characteristic neurotransmitters, autonomic nerves influence surrounding tissues through the release of other active chemicals including ATP, nitric oxide, and a range of peptides, e.g., substance P and vasoactive intestinal peptide. As a result of their different final transmitters, the effects of the two subsystems differ. Sympathetic stimulation readies an animal for interaction with the outside world and prepares the animal for "fight or flight"; e.g., activation of sympathetic axons increases heart rate and decreases gastrointestinal peristalsis. On the other hand, parasympathetic stimulation relaxes and quiets an animal; e.g., activation of parasympathetic axons decreases heart rate and increases gastrointestinal peristalsis. The accompanying table compares the effects of sympathetic and parasympathetic stimulation on specific tissues. See: parasympathetic nervous system; sympathetic nervous system; illustrationtable PathologyThe ANS is distributed throughout the body, and autonomic dysfunction can produce a wide range of symptoms, such as bladder malfunction, blood pressure abnormalities, breathing difficulty, gastrointestinal motility problems, heart arrhythmias, impotence, nasal congestion, sweating disorders, syncope, and visual symptoms. Drugs that act on or mimic autonomic neurotransmitters are commonly used to alleviate these symptoms as well as other conditions, such as glaucoma, heart failure, shock, and thyroid storm. To assess the overall functioning of the ANS, physicians often begin with simple measurements of the reflexive responses of the cardiovascular system; specifically, they measure the changes of blood pressure and heart rate as a person stands from sitting and exercises. Tissue: | Effects: |
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| Sympathetic Stimulation | Parasympathetic Stimulation |
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adipose tissue | lipolysis | adrenal cortex | | | secretion (corticoids) | increase | | adrenal medulla | | | secretion (adrenaline) | increase | | arteries | | | abdominal organs | constriction | | coronary | dilation | | skin and mucosa | constriction | | bladder | | | wall (detrusor) muscle | relaxation | contraction | sphincter | contraction | relaxation | gall bladder | | | wall muscle | relaxation | contraction | duct | dilation | constriction | heart | | | AV node (conduction velocity) | increase | decrease | SA node (rate) | increase | decrease | atrial muscle (contractility) | increase | decrease | ventricular muscle (contractility) | increase | | intestine | wall muscle (tone and motility) | decrease | increase | secretion | decrease | increase | rectal sphincter muscle | contraction | relaxation | kidney | | | secretion (renin) | increase | | lacrimal gland | | | secretion (tears) | | increase | liver | | | metabolism | glycogenolysis, gluconeogenesis | glycogen synthesis | bile secretion | decrease | increase | lung | | | airways | dilation | constriction | secretion (airway glands) | | increase | nasopharynx | | | secretion (mucosal glands) | | increase | pancreas | | | secretion (enzymes and insulin) | decrease | increase | secretion (glucagon) | increase | | pineal gland | | | melatonin synthesis | stimulation | | pupil | dilation | constriction | reproductive tract | | | muscles | contractions | blood vessels | constriction | dilation, erection | salivary gland | | | secretion | decrease | increase | skeletal muscle | increase contractility, glycogenolysis | | skin | | | pilomotor muscle | contraction | | secretion (sweat) | increase | | spleen | | | capsule | contraction | | stomach | | | wall muscle (tone and motility) | decrease | increase | secretion | decrease | increase | uterus | | | pregnant | contraction | | nonpregnant | relaxation | |
Autonomic nervous system (ANS)The part of the nervous system that supplies nerve endings in the blood vessels, heart, intestines, glands, and smooth muscles, and governs their involuntary functioning. The autonomic nervous system is responsible for the biochemical changes involved in experiences of anxiety.Mentioned in: AnxietyANS Abbreviation for autonomic nervous system.LegalSeeAnFinancialSeeANANS
Acronym | Definition |
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ANS➣Answer | ANS➣American Nuclear Society | ANS➣Advanced Networking Services | ANS➣Answer (logging abbreviation) | ANS➣American National Standard | ANS➣Aquatic Nuisance Species | ANS➣Autonomic Nervous System | ANS➣Ammonium Nitrate Solution | ANS➣Air Navigation Service | ANS➣American Numismatic Society | ANS➣Anna Nicole Smith | ANS➣Army Nursing Service | ANS➣Agência Nacional de Saúde (National Agency of Suplemental Health; Brazil) | ANS➣Academy of Natural Sciences | ANS➣Ansvarlig Selskap | ANS➣Algemene Nederlandse Spraakkunst (Dutch grammar book) | ANS➣Advanced Networking Software | ANS➣Answer Message | ANS➣Advances in Nursing Science | ANS➣Advanced Network and Services | ANS➣Advanced Neuromodulation Systems | ANS➣Air Navigation System | ANS➣Advanced Network Solutions | ANS➣AirNet Systems (Columbus, OH) | ANS➣American Name Society | ANS➣Alaskan North Slope | ANS➣Advanced Neutron Source | ANS➣Autonomous Navigation System | ANS➣Answer Tone | ANS➣Alaska Native Sisterhood | ANS➣Anthocyanidin Synthase | ANS➣Applied Natural Sciences, Inc. (Hamilton, OH; est. 1993) | ANS➣Authoritative Name Server | ANS➣Application Networking Service (Cisco) | ANS➣Acuerdo de Nivel de Servicio (Spanish: Service Level Agreement) | ANS➣Astronomical Netherlands Satellite | ANS➣American Neurotology Society | ANS➣Advanced Networks and Services | ANS➣Apple Network Server (Apple Computers) | ANS➣Azerbaijan News Service | ANS➣Acorn News Service (mailing list) | ANS➣Alcatel Network Systems | ANS➣Associação Nacional de Sargentos (Portugal - Sargeants National Association) | ANS➣Agentia Nationala pentru Sport (Romania) | ANS➣ATM Name Service | ANS➣Artificial Neural System | ANS➣Adaptive Noise Shaping (DSP, psychoacoustics) | ANS➣Atlantic Nuclear Services Ltd. | ANS➣Area Navigation System | ANS➣Astro-Inertial Navigation System | ANS➣Alternative News Source | ANS➣Archbishop Neale School (Charles County, Maryland) | ANS➣Action Nord Sud Handicap International | ANS➣Actiefront Nationale Socialisten | ANS➣Automatic Notification System | ANS➣Anglican News Service | ANS➣Advanced Narrowband System | ANS➣Anilinonaphthalene Sulfonates | ANS➣Active Network Service | ANS➣American National School | ANS➣Arkansas Numismatic Society | ANS➣Advanced Navigation School | ANS➣Automatic Network Synchronization | ANS➣Aeromedical Neuropsychiatric Standards | ANS➣Anti-Navy Supersonic | ANS➣Async Network Survivability | ANS➣Applications Network Software | ANS➣Ameritech Network Services |
ANS
Synonyms for ANSnoun the part of the nervous system of vertebrates that controls involuntary actions of the smooth muscles and heart and glandsSynonymsRelated Words- autonomic ganglion
- nervous system
- systema nervosum
- neural structure
- sympathetic nervous system
- parasympathetic
- parasympathetic nervous system
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