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central nervous system |
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system /sys·tem/ (sis´tim) 1. a set or series of interconnected or interdependent parts or entities (objects, organs, or organisms) that act together in a common purpose or produce results impossible by action of one alone. 2. a school or method of practice based on a specific set of principles. alimentary system digestive s. auditory system the series of structures by which sounds are received from the environment and conveyed as signals to the central nervous system; it consists of the outer, middle, and inner ear and the tracts in the auditory pathways. autonomic nervous system the portion of the nervous system concerned with regulation of activity of cardiac muscle, smooth muscle, and glands, usually restricted to the sympathetic and parasympathetic nervous systems. Bethesda System a classification of cervical and vaginal cytology used in cytopathologic diagnosis. cardiovascular system the heart and blood vessels, by which blood is pumped and circulated through the body. CD system [c luster d esignation] a system for classifying cell surface markers expressed by lymphocytes based on a computer analysis grouping similar monoclonal antibodies raised against human leukocyte antigens. centimeter-gram-second system (CGS) (cgs) a system of measurements in which the units are based on the centimeter as the unit of length, the gram as the unit of mass, and the second as the unit of time. central nervous system (CNS) the brain and spinal cord. centrencephalic system the neurons in the central core of the brain stem from the thalamus to the medulla oblongata, connecting the two hemispheres. chromaffin system the chromaffin cells of the body considered collectively. circulatory system channels through which nutrient fluids of the body flow; often restricted to the vessels conveying blood. colloid system , colloidal system see colloid (2). conduction system of heart a system of specialized muscle fibers that generate and transmit cardiac impulses and coordinate contractions, comprising the sinoatrial and atrioventricular nodes, bundle of His and its bundle branches, and subendocardial branches of Purkinje fibers. digestive system the organs concerned with ingestion, digestion, and absorption of food or nutritional elements. endocrine system the glands and other structures that elaborate and secrete hormones that are released directly into the circulatory system, influencing metabolism and other body processes; included are the pituitary, thyroid, parathyroid, and adrenal glands, pineal body, gonads, pancreas, and paraganglia. enteric nervous system the enteric plexus, sometimes considered separately from the autonomic nervous system because it has independent local reflex activity. extrapyramidal system a functional, rather than anatomical, unit comprising the nuclei and fibers (excluding those of the pyramidal tract) involved in motor activities; they control and coordinate especially the postural, static, supporting, and locomotor mechanisms. It includes the corpus striatum, subthalamic nucleus, substantia nigra, and red nucleus, along with their interconnections with the reticular formation, cerebellum, and cerebrum. genitourinary system urogenital s. haversian system a haversian canal and its concentrically arranged lamellae, constituting the basic unit of structure in compact bone (osteon). heterogeneous system a system or structure made up of mechanically separable parts, as an emulsion or a suspension. His-Purkinje system a portion of the conducting system of the heart, usually referring specifically to the segment beginning with the bundle of His and ending at the terminus of the Purkinje fiber network within the ventricles. homogeneous system a system or structure made up of parts which cannot be mechanically separated, as a solution. hypophysioportal system , hypothalamo-hypophysial portal system the venules connecting the capillaries (gomitoli) in the median eminence of the hypothalamus with the sinusoidal capillaries of the adenohypophysis. immune system a complex system of cellular and molecular components having the primary functions of distinguishing self from not self and of defense against foreign organisms or substances. International System of Units see SI unit, under unit. keratinizing system the cells composing the bulk of the epithelium of the epidermis, which are of ectodermal origin and undergo keratinization and form the dead superficial layers of the skin. limbic system a group of brain structures (including the hippocampus, gyrus fornicatus, and amygdala) common to all mammals; it is associated with olfaction, autonomic functions, and certain aspects of emotion and behavior. locomotor system the structures in a living organism responsible for locomotion, in humans consisting of the muscles, joints, and ligaments of the lower limbs as well as the arteries and nerves that supply them. lymphatic system the lymphatic vessels and lymphoid tissue, considered collectively. lymphoid system the lymphoid tissue of the body, collectively; it consists of (a) a central component, including the bone marrow, thymus, and an unidentified portion called bursal equivalent tissue; and (b) a peripheral component consisting of lymph nodes, spleen, and gut-associated lymphoid tissue (tonsils, Peyer's patches). lymphoreticular system the tissues of the lymphoid and reticuloendothelial systems considered together as one system. masticatory system the bony and soft structures of the face and mouth involved in mastication, and the vessels and nerves supplying them. metric system a decimal system of weights and measures based on the meter. mononuclear phagocyte system (MPS) the set of cells consisting of macrophages and their precursors (blood monocytes and their precursor cells in bone marrow). The term has been proposed to replace reticuloendothelial system, which does not include all macrophages and does include other unrelated cell types. muscular system the muscles of the body considered collectively; generally restricted to the voluntary, skeletal muscles. nervous system the organ system which, along with the endocrine system, correlates the adjustments and reactions of the organism to its internal and external environment, comprising the central and peripheral nervous systems. parasympathetic nervous system the craniosacral portion of the autonomic nervous system, its preganglionic fibers traveling with cranial nerves III, VII, IX, X, and XI, and with the second to fourth sacral ventral roots; it innervates the heart, smooth muscle and glands of the head and neck, and thoracic, abdominal, and pelvic viscera. peripheral nervous system all elements of the nervous system (nerves and ganglia) outside the brain and spinal cord. portal system an arrangement by which blood collected from one set of capillaries passes through a large vessel or vessels and another set of capillaries before returning to the systemic circulation, as in the pituitary gland and liver. Purkinje system a portion of the conducting system of the heart, usually referring specifically to the Purkinje network. respiratory system respiratory tract; the tubular and cavernous organs that allow atmospheric air to reach the membranes across which gases are exchanged with the blood. reticular activating system the system of cells of the reticular formation of the medulla oblongata that receive collaterals from the ascending sensory pathways and project to higher centers; they control the overall degree of central nervous system activity, including wakefulness, attentiveness, and sleep; abbreviated RAS. reticuloendothelial system (RES) a group of cells having the ability to take up and sequester inert particles and vital dyes, including macrophages and macrophage precursors, specialized endothelial cells lining the sinusoids of the liver, spleen, and bone marrow, and reticular cells of lymphatic tissue (macrophages) and bone marrow (fibroblasts). See also mononuclear phagocyte s. SI system see under unit. stomatognathic system structures of the mouth and jaws, considered collectively, as they subserve the functions of mastication, deglutition, respiration, and speech. sympathetic nervous system (SNS) the thoracolumbar part of the autonomic nervous system, the preganglionic fibers of which arise from cell bodies in the thoracic and first three lumbar segments of the spinal cord; postganglionic fibers are distributed to the heart, smooth muscle, and glands of the entire body. urinary system the organs and passageways concerned with the production and excretion of urine, including the kidneys, ureters, urinary bladder, and urethra. urogenital system the urinary system considered together with the organs of reproduction. vascular system circulatory s. visual system the series of structures by which visual sensations are received from the environment and conveyed as signals to the central nervous system; it consists of the photoreceptors in the retina and the afferent fibers in the optic nerve, chiasm, and tract.
Central nervous system (CNS) Part of the nervous system consisting of the brain, cranial nerves and spinal cord. The brain is the center of higher processes, such as thought and emotion and is responsible for the coordination and control of bodily activities and the interpretation of information from the senses. The cranial nerves and spinal cord link the brain to the peripheral nervous system, that is the nerves present in the rest of body. Mentioned in: Analgesics, Opioid, Antinausea Drugs, Antiparkinson Drugs, Barbiturates, Benzodiazepines, Brain Tumor, Caffeine, Central Nervous System Stimulants, Cocaine, Diabetic Neuropathy, Insecticide Poisoning, Monoamine Oxidase Inhibitors, Muscle Relaxants, Peripheral Neuropathy, Selective Serotonin Reuptake Inhibitors central nervous system (CNS) Etymology: Gk, kentron + L, nervus, nerve; Gk, systema one of the two main divisions of the nervous system, consisting of the brain and the spinal cord. The central nervous system processes information to and from the peripheral nervous system and is the main network of coordination and control for the entire body. The brain controls many functions and sensations, such as sleep, sexual activity, muscular movement, hunger, thirst, memory, and emotions. The spinal cord extends various types of nerve fibers from the brain and acts as a switching and relay terminal for the peripheral nervous system. The 12 pairs of cranial nerves emerge directly from the brain. Sensory nerves and motor nerves of the peripheral system leave the spinal cord separately between the vertebrae but unite to form 31 pairs of spinal nerves containing sensory fibers and motor fibers. More than 10 billion neurons constitute but one tenth of the brain cells; the other cells consist of neuroglia that support the neurons. The neurons and the neuroglia form the soft, jellylike substance of the brain, which is supported and protected by the skull. The brain and the spinal cord are composed of gray matter and white matter. The gray matter primarily contains nerve cells and associated processes; the white matter consists predominantly of bundles of myelinated nerve fibers. Compare peripheral nervous system. See also brain, spinal cord. central nervous system (CNS), n that portion of the nervous system consisting of the brain and spinal cord. The portion of the nervous system beyond the brain and cord is known as the peripheral nervous system. central pertaining to a center; located at the midpoint. central artery of the optic nerve, the source of the retinal artery. See also Table 9. central channel the fast-flowing channel through the capillary bed, the rate controlled by the metarterioles which exert a sphincter-like action on the system. central convulsions convulsions arising from stimulation of the central nervous system, as distinct from those caused by lesions elsewhere. central cord syndrome injury to the central portion of the cervical spinal cord resulting in disproportionately more weakness or paralysis in the forelimbs than in the hindlimbs; pathological change is caused by hemorrhage or edema. central diabetes insipidus see diabetes insipidus. central European tick-borne encephalitis see encephalitis. central layer central of the three layers of gray matter in the cerebellum; the principal cell type is piriform. central nervous system see central nervous system. central peripheral neuropathy see Boxer progressive axonopathy. central progressive retinal atrophy see central progressive retinal atrophy. central projection law the laws of physics applied to the primary x-ray beam of photons, e.g. the closer the object being x-rayed is to the film the sharper will be its definition. central respiratory oscillator pool of nerve cells in the pons and medulla oblongata which are responsible for the rhythmic to-and-fro movements of respiration. central retinal degeneration see retinal. central sulcus fissure of Rolando. central tarsal bone the bone of the hock which lies between the proximal and distal rows of tarsal bones. central tendon of diaphragm see diaphragmatic tendon. central vein the centrally placed drainage vessel of each hepatic lobule, receiving blood from the hepatic sinusoids. central venous catheterization insertion of an indwelling catheter into a central vein for the purpose of administering fluid and medications and for the measurement of central venous pressure (see below). central venous pressure (CVP) the pressure of blood in the right atrium, measured by an in situ catheter in the right atrium, is a much better guide of the degree of vasogenic peripheral failure than is arterial blood pressure. The technique is used mainly in dogs and cats. nervous 1. pertaining to a nerve or nerves. 2. unduly excitable. nervous acetonemia in contrast to the more common form of this disease of cattle, the wasting form, this one is manifested by delirious signs of circling, head pushing, leaning, straddling, forceful licking including themselves, salivation and incoordination. There is a strong acetonuria and odor on the breath. autonomic nervous system the branch of the nervous system that works without conscious control. The voluntary nervous system governs the striated or skeletal muscles, whereas the autonomic governs the glands, the cardiac muscle, and the smooth muscles, such as those of the digestive system, the respiratory system and the skin. The autonomic nervous system is divided into two subsidiary systems, the sympathetic system and the parasympathetic system. It is also divided into central and peripheral sections. The core of the central section is the hypothalamus which receives afferent input from many other parts of the brain including the cerebral cortex. Its efferent output goes to many lower centers in the nervous system that have visceral control as their functions, e.g. the respiratory center in the medulla. The peripheral section consists of nonmedullated nerve fibers that leave the central nervous system in the craniosacral outflow (parasympathetic system) or the thoracolumbar outflow (sympathetic) system, and terminate in effector organs after passing through a ganglion, visible paravertebral ganglia in the sympathetic system, or ganglia embedded in the wall of the target organ in the parasympathetic system. central nervous system nervous dysfunction can occur in any of four ways: (1) Excitation or irritation, an increase in the number of electrical stimuli or facilitation in their passage. (2) Release phenomena, from the damping, modifying effects of higher centers; includes spasticity, exaggerated tendon jerks. (3) paralysis, due to reduction or cessation of transmission of nerve impulses. (4) Nervous shock, a temporary cessation of activity in the nervous system as a whole in response to an insult applied to a part of it. nervous excitation see nervous dysfunction (above). nervous paralysis see nervous dysfunction (above). peripheral nervous system the portion of the nervous system consisting of the nerves and ganglia outside the brain and spinal cord. nervous release phenomena see nervous dysfunction (above). nervous shock see nervous dysfunction (above). nervous system the organ system that along with the endocrine system, correlates the adjustments and reactions of an organism to internal and environmental conditions, comprising the central, peripheral and autonomic nervous systems. Patient discussion about Central nervous system agents. Q. Fibromyalgia deeply affect the CNS? Do fibromyalgia deeply affect the CNS (central nervous system)? A. Fibromyalgia is somewhat related to central nervous system. Fibromyalgia can ultimately disrupt the flow of neurotransmitters between the body and the brain. As a result, fibromyalgia can cause the patient to feel continuous pain, and create chronic muscle spasms. In addition, fibromyalgia patients are often subject to abnormally light a sleeping pattern which prevents the normal production of serotonin and growth hormone normally produced during stage 4 (deep) sleep. This inhibits the body’s ability to heal itself, and may contribute to the overwhelming fatigue and depression experienced by those with FMS. Q. Is fibromyalgia related to Central Nervous System? Is fibromyalgia related to Central Nervous System? Among men and women who is more prone to the symptoms of fibromyalgia? A. here is a quote from the National Fibromyalgia Association site: Read more or ask a question about Central nervous system agents"Little research has been conducted that measures the prevalence of fibromyalgia, and estimates vary widely as to the proportion of male versus female patients. A 1999 epidemiology study conducted in London found a female to male ratio of roughly three to one. However, a 2001 review of the research literature in Current Rheumatology Reports stated the ratio was nine to one." How to thank TFD for its existence? Tell a friend about us, add a link to this page, add the site to iGoogle, or visit webmaster's page for free fun content. |
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ASTA Medica AG is a 900 million dollar a year company with leading products in the fields of anticancer drugs, central nervous system agents, and respiratory therapies. ASTA Medica AG is a 900 million dollar a year company with leading products in the fields of anticancer drugs, central nervous system agents, and respiratory therapies. ASTA Medica AG is a billion dollar a year company with leading products in the fields of anticancer drugs, central nervous system agents, and respiratory therapies. |
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