peripheral nervous system (redirected from peripheral nervous systems)

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.

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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.

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peripheral nervous system

n.

The part of the vertebrate nervous system constituting the nerves outside the central nervous system and including the cranial nerves, the spinal nerves, and the sympathetic and parasympathetic nervous systems.

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Peripheral nervous system (PNS)

One of the two major divisions of the nervous system. PNS nerves link the central nervous system with sensory organs, muscles, blood vessels, and glands.

Mentioned in: Diabetic Neuropathy, Numbness and Tingling, Peripheral Neuropathy, Spinal Cord Injury

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peripheral nervous system,

the motor and sensory nerves and ganglia outside the brain and spinal cord. The system consists of 12 pairs of cranial nerves, 31 pairs of spinal nerves, and their various branches in body organs. Sensory, or afferent, peripheral nerves transmitting information to the central nervous system and motor, or efferent, peripheral nerves carrying impulses from the brain usually travel together but separate at the cord level into a posterior sensory root and an anterior motor root. Fibers innervating the body wall are designated somatic. Those supplying internal organs are termed visceral. The autonomic system includes the peripheral nerves involved in regulating cardiovascular, respiratory, endocrine, and other automatic body functions. Nerves in the sympathetic or thoracolumbar division of the autonomic system secrete norepinephrine and cause peripheral vasoconstriction, cardiac acceleration, coronary artery dilation, bronchodilation, and inhibition of peristalsis. Parasympathetic nerves, which constitute the craniosacral division of the autonomic system, secrete acetylcholine; cause peripheral vasodilation, cardiac inhibition, and bronchoconstriction; and stimulate peristalsis. Injury to a peripheral nerve results in loss of movement and sensation in the area innervated distal to the lesion.

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peripheral nervous system,

n the motor and sensory nerves and ganglia outside the brain and spinal cord.

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nervous

1. pertaining to a nerve or nerves.

2. unduly excitable.

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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

the portion of the nervous system consisting of the brain and spinal cord. See also nervous, brain, cerebral.

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.

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peripheral

pertaining to or situated at or near the periphery.

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peripheral circulatory failure

see circulatory failure.

peripheral gangrenous ergotism

gangrene of the tips of the ears and tail and of the lower limbs caused by rye ergot poisoning; see also rye ergot.

peripheral giant cell granuloma

see giant-cell epulis.

peripheral lymphatics

see lymphatic.

peripheral nerve

see peripheral nerve.

peripheral nerve degeneration

see axonal degeneration, wallerian degeneration.

peripheral nerve paralysis

see peripheral nerve.

peripheral nervous system

see peripheral nervous system.

peripheral proteins

see membrane proteins.

peripheral sinus

the peripheral lymph space just beneath the capsule of a lymph node.