| nervous system n. The system of cells, tissues, and organs that regulates the body's responses to internal and external stimuli. In vertebrates it consists of the brain, spinal cord, nerves, ganglia, and parts of the receptor and effector organs. |
nervous system
n
(Life Sciences & Allied Applications / Physiology) the sensory and control apparatus of all multicellular animals above the level of sponges, consisting of a network of nerve cells (see neurone) See also central nervous system
nervous system (nûr v s) The system of neurons and tissues that regulates the actions and responses of vertebrates and many invertebrates. The nervous system of vertebrates is a complex information-processing system that consists mainly of the brain, spinal cord, and peripheral and autonomic nerves. It receives chemical information from hormones in the circulating blood and can also regulate secretions of the endocrine system by the action of neurohormones. The nervous systems of invertebrates vary from a simple network of nerves to a complex nerve network under the control of a primitive brain. See also autonomic nervous systemcentral nervous systemperipheral nervous system |
ThesaurusLegend: Synonyms Related Words Antonyms
| Noun | 1. |  nervous system - the sensory and control apparatus consisting of a network of nerve cellsbody, organic structure, physical structure - the entire structure of an organism (an animal, plant, or human being); "he felt as if his whole body were on fire" system - a group of physiologically or anatomically related organs or parts; "the body has a system of organs for digestion" nerve tissue, nervous tissue - tissue composed of neurons ganglion - an encapsulated neural structure consisting of a collection of cell bodies or neurons nerve cell, neuron - a cell that is specialized to conduct nerve impulses central nervous system, CNS, systema nervosum centrale - the portion of the vertebrate nervous system consisting of the brain and spinal cord neural net, neural network - any network of neurons or nuclei that function together to perform some function in the body peripheral nervous system, systema nervosum periphericum - the section of the nervous system lying outside the brain and spinal cord ANS, autonomic nervous system - the part of the nervous system of vertebrates that controls involuntary actions of the smooth muscles and heart and glands sympathetic 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 vessels parasympathetic, 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 |
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