Nerve Center

the aggregation of nerve cells, or neurons, in the nervous system that continuously participate in the execution of reflexes and in the regulation of a particular function or some aspect of that function. The neurons that make up a nerve center are for the most part strictly localized.

The simplest nerve center consists of a few neurons that constitute an isolated ganglion. For example, in some crustaceans the cardiac ganglion, which comprises only nine neurons, controls the heartbeat. In highly organized animals nerve centers are part of the central nervous system (CNS), and may consist of thousands and even millions of neurons.

Each nerve center receives information by way of nerve fibers from the sense organs or from other nerve centers. This input is in the form of nerve impulses. The information is analyzed by those nerve center neurons whose outgrowths—or axons—do not extend beyond the center. The final link is made by the neurons whose outgrowths do leave the nerve center; command impulses from the center are delivered along these efferent pathways to the peripheral organs or to other nerve centers. The neurons that constitute a nerve center are linked together by excitatory and inhibitory synapses to form nerve nets (not to be confused with the term “nerve net” as applied to invertebrates). In addition to consisting of neurons that are excited only in response to incoming nerve signals or to the action of various serum chemical stimuli, a nerve center may also consist of pacemaker neurons, which are automatic. Pacemaker neurons have the capacity to generate periodic nerve impulses.

The concept of the nerve center implies that the various functions of the body are regulated by different segments of the nervous system. The location of a nerve center is experimentally determined by stimulation or destruction of certain parts of the brain and spinal cord. Ablation studies and studies involving discrete lesions are also used. If stimulation of a certain segment of the CNS elicits a physiological reaction or reflex that disappears when the affected portion of the CNS is removed or destroyed, then it is safe to assume that the experimenter is dealing with a nerve center that is actively involved in a particular physiological reaction or reflex.

The concept of localization of function in the nervous system is not universally agreed upon; at best, it is accepted with reservations. The objections are based on two lines of experimental evidence. The first underscores the plasticity of certain portions of the nervous system. It is this capacity for functional reconstruction that compensates, for example, for the loss of the medulla. The second line of evidence proves that structures that are located in different segments of the nervous system are interconnected and may affect the performance of a single function. This latter line of evidence has led some physiologists to completely reject the localization of function and others to broaden the concept of the nerve center to include all the structures that affect the performance of a given function. Modern neurophysiology has reconciled this difference of opinion by invoking the idea of a functional hierarchy in a nerve center. According to this conceptualization, the separate components of a single function are controlled by nerve centers located at different levels of the nervous system. The coordinated activity of the nerve centers that constitute this hierarchical system guarantees the uniform performance of a complex function. This is the basis for any given function’s adaptive character.

The concept of nerve center dominance, one of the most important principles underlying the activity of a nerve center, was formulated during the years 1911 to 1923 by A. A. Ukhtomskii.

REFERENCES

Obshchaia i chastnaia fiziologiia nervnoi sistemy. Leningrad, 1969.
Fiziologiia cheloveka, 2nd ed. Edited by E. B. Babskii. Moscow, 1972.

D. A. SAKHAROV

nerve center

center

[sen´ter] 1. a point from which a process starts, especially a plexus or ganglion giving off nerves that control a function.2. nerve center.3. an agency or other site where services are offered to the public.accelerating center the vasomotor center in the brainstem involved in acceleration of heart action.apneustic center a nerve center in the brainstem controlling normal respiration.Broca's center Broca's motor speech area.cardioinhibitory center a vasomotor center in the medulla oblongata that exerts an inhibitory influence on the heart.cardiovascular control c's vasomotor centers.community mental health center (CMHC) a mental health facility or group of affiliated agencies that provide services to a designated catchment area.coughing center a nerve center in the medulla oblongata, situated above the respiratory center, which controls the act of coughing.deglutition center a nerve center in the medulla oblongata that controls swallowing.detente center a residential care center of the kinlein type, using the esca theory of moving as the basis for the staff's actions to maintain the independence of residents who are experiencing lessened physical or mental capacity.C's for Disease Control and Prevention (CDC) an agency of the United States Department of Health and Human Services whose headquarters is in Atlanta, Georgia. It is concerned with all phases of control of communicable, vector-borne, and occupational diseases and with the prevention of disease, injury, and disability. Its responsibilities include epidemiology, surveillance, detection, laboratory science, ecological investigations, training, disease control methods, chronic disease prevention, health promotion, and injury prevention and control. Its major tasks include the licensing of qualified clinical laboratories for interstate commerce, maintenance of laboratories as reference centers for microorganisms and infectious diseases, and operation of extensive research programs in the prevention, detection and control of disease. The CDC's name has changed several times to reflect its expanding role; it has been called the Communicable Disease Center (1946), the Center for Disease Control (1970), and the Centers for Disease Control (1980). The latest name change, enacted by Congress in 1992, reflects the expansion of the scope of the CDC's mission to include health promotion and education. Because of the widespread recognition of the acronym CDC, that acronym continues to be used by the agency. The mailing address of the CDC is Centers for Disease Control and Prevention, 1600 Clifton Rd. NE, Atlanta, GA 30333, and the website is http://www.cdc.gov.ejaculation center a reflex center in the lumbar spinal cord that regulates ejaculation of semen during sexual stimulation.erection center a reflex center in the sacral spinal cord that regulates erection of the penis or clitoris. Called also genital center.feeding center a group of cells in the lateral hypothalamus that when stimulated cause a sensation of hunger; called also hunger center.genital center erection center.germinal center the area in the center of a lymph node containing aggregations of actively proliferating lymphocytes.health center 1. a community health organization providing ambulatory health care and referrals to appropriate service agencies, and coordinating the efforts of all health agencies.2. an educational complex consisting of a medical college, nursing college, and various allied health professional schools.heat-regulating c's thermoregulatory centers.hunger center feeding center.medullary respiratory center the nerve center in the medulla oblongata that coordinates respiratory movements.micturition c's a nerve center controlling the bladder and inhibiting the tension of the vesical sphincter, situated in the lumbar enlargement.nerve center a collection of nerve cells in the central nervous system that are associated together in the performance of some particular function, such as a area" >primary area or an area" >association area.nursing center a site where public health or primary care services, including patient education, assessment, and screening and preventive services are provided and managed by registered nurses.center of ossification any point in bones at which ossification begins.pneumotaxic center a nerve center in the upper pons that rhythmically inhibits inhalation.poison center (poison control center) see poison control center.rectovesical center a reflex center in the spinal cord that regulates the rectum and bladder.reflex center any nerve center at which afferent sensory impressions are converted into efferent motor impulses.respiratory c's a series of nerve centers (the apneustic, pneumotaxic, and medullary respiratory centers) in the medulla and pons that coordinate respiratory movements.satiety center a group of cells in the ventromedial hypothalamus that when stimulated suppress the desire for food.senior center a program supported by Title XX funding, providing recreational activities and lunch for a small fee for older adults in need of socialization. Health assessments and education may also be provided.sudorific center 1. a nerve center in the anterior hypothalamus controlling sweating.2. any of several nerve centers in the medulla oblongata or spinal cord that exercise parasympathetic control over sweating. Called also sweat center.swallowing center deglutition center.sweat center sudorific center.thermoregulatory c's nerve centers in the hypothalamus that regulate the conservation and dissipation of heat.thirst center a group of cells in the lateral hypothalamus that when stimulated cause a sensation of thirst.trauma center an institution officially designated as a site to which catastrophically injured patients can be brought quickly to receive specialized care. Trauma centers are classified as Level I, II, or III according to criteria developed by the Committee on Trauma of the American College of Surgeons, with Level I facilities having the equipment and personnel necessary to care for the most seriously injured patients.vasoconstrictor center a nerve center in the medulla oblongata and lower pons that controls contraction of the blood vessels.vasodilator center a nerve center in the medulla oblongata that causes dilation of blood vessels by repressing the activity of the vasoconstrictor center.vasomotor c's nerve centers in the medulla oblongata and the lower pons that regulate the caliber of the blood vessels and increase or decrease the heart rate and contractility. See also vasoconstrictor c. and vasodilator c. Called also cardiovascular control c's.vomiting center a center in the lower central region of the medulla oblongata; its stimulation causes vomiting.word center, auditory Wernicke's area.

nerve center

n.1. A group of closely connected nerve cells that perform a specific function.2. A source of power or control: Our Boston office is the nerve center of the corporation.

nerve center

An area in the central nervous system or in a ganglion that is responsible for certain functions; examples include the motor areas in the frontal lobes of the cerebrum.See also: center

nerve center

nerve center

nerve′ cen`ter

Nerve Center

Nerve Center

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nerve center

center

nerve center

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nerve center

Synonyms for nerve center

noun a center that provides information and control

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noun a cluster of nerve cells governing a specific bodily process

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