body, organic structure, physical structure - the entire physical structure of an organism (especially an animal 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

fasciculus, fiber bundle, fibre bundle, fascicle - a bundle of fibers (especially nerve fibers)

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