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Neuralgia - what is that? Neuralgia = pain at the nerve endings, usually induced by a disturbed "food" supply of a nerve
The Central Nervous SystemThe central nervous system is a network of specialized tissue that controls actions and reactions of the body, enabling it to adjust to its environment. The system functions by receiving signals from all parts of the body, relaying them to the brain and spinal cord, and then sending appropriate return signals to muscles and body organs.
Virtually all multicellular animals have at least a rudimentary nervous system; in vertebrates the system is most complex. The basic unit of the nervous system is the nerve cell (neuron). Of the billions of neurons in humans, half are in the brain. The neuron consists of a cell body, containing the cell nucleus; dendrites, branch like extensions that receive incoming signals; and the axon, the long cell extension that carries signals long distances. A neuron works by receiving chemical signals-some excitatory, some inhibitory-through its dendrites and sending electrical impulses along its axon. Chemicals (NEUROTRANSMITTERS) released at the terminal fibers of the axon diffuse across a junction called the synapse and bind to dendrites of recipient neurons. Dendrites and axons are called nerve fibers; a nerve is a bundle of nerve fibers. The nervous system has two divisions: the central nervous system and peripheral nervous system. The central nervous system, consisting of the brain and spinal cord, receives impulses from receptors in the skin and organs via sensory (afferent) nerve fibers; it returns impulses via motor (efferent) fibers to terminals in muscles and glands. Peripheral nerves mediate these pathways. The peripheral nervous system comprises cranial nerves, controlling face and neck; spinal nerves, radiating to other parts of the body; and autonomic nerves, which form a subsidiary system regulating the iris of the eye and muscles of heart, glands, lungs, stomach, and other visceral organs. The autonomic nervous system, in turn, comprises the sympathetic nervous system, which functions in response to short-term stress (e.g., increasing heart rate), and the parasympathetic nervous system, which acts in opposition to the sympathetic (e.g., lowering heart rate). With permission re-published from the The Concise Columbia Electronic Encyclopedia © Columbia University Press.
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