metric system (redirected from metric 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.

---

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.

---

metric system

n.

A decimal system of units based on the meter as a unit length, the kilogram as a unit mass, and the second as a unit time.

---

metric system,

a decimal system of measurement based on the meter (39.37 inches) as the unit of length, on the gram (15.432 grains) as the unit of weight or mass, and, as a derived unit, on the liter (0.908 U.S. dry quart or 1.0567 U.S. liquid quart) as the unit of volume.

---

metric [met´rik]

1. pertaining to measures or measurement.

2. having the meter as a basis.

metric system the system of units of measurement that is based on the meter, gram, and liter and in which new units are formed from the basic terms by prefixes denoting multiplication by a power of ten. See also si units.

---

system [sis´tem]

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. an organized set of principles or ideas. adj., adj systemat´ic, system´ic.

The parts of a system can be referred to as its elements or components; the environment of the system is defined as all of the factors that affect the system and are affected by it. A living system is capable of taking in matter, energy, and information from its environment (input), processing them in some way, and returning matter, energy, and information to its environment as output.

An open system is one in which there is an exchange of matter, energy, and information with the environment; in a closed system there is no such exchange. A living system cannot survive without this exchange, but in order to survive it must maintain pattern and organization in the midst of constant change. Control of self-regulation of an open system is achieved by dynamic interactions among its elements or components. The result of self-regulation is referred to as the steady state; that is, a state of equilibrium. homeostasis is an assemblage of organic regulations that act to maintain steady states of a living organism.

A system can be divided hierarchically into subsystems, which can be further subdivided into sub-subsystems and components. A system and its environment could be considered as a unified whole for purposes of study, or a subsystem could be studied as a system. For example, the collection of glands in the endocrine system can be thought of as a system, each endocrine gland could be viewed as a system, or even specific cells of a single gland could be studied as a system. It is also possible to think of the human body as a living system and the endocrine system as a subsystem. The division of a system into a subsystem and its environment is dependent on the perspective chosen by the person studying a particular phenomenon.

Systems, subsystems, and suprasystems. Within the environment there are suprasystems, such as human society, and systems within the suprasystem, such as the educational and industrial systems and the health care delivery system. Within the health care delivery system are subsystems, such as the patient, family members, the nurse, the physician, and allied health care professionals and paraprofessionals.

alimentary system digestive system.

apothecaries' system see apothecaries' system.

autonomic nervous system see autonomic nervous system.

avoirdupois system see avoirdupois system.

behavioral system in the behavioral system model of nursing, the patterned, repetitive, and purposeful behaviors of an individual.

cardiovascular system the heart and blood vessels, by which blood is pumped and circulated through the body; see also circulatory system.

CD system (cluster designation) a system for classifying cell-surface markers expressed by lymphocytes based on a computer analysis of monoclonal antibodies against hla antigens, with antibodies having similar specificity characteristics being grouped together and assigned a number (CD1, CD2, CD3, etc.); these CD numbers are also applied to the specific antigens recognized by the various groups of monoclonal antibodies. See also CD antigen.

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 see central nervous system.

centrencephalic system the neurons in the central core of the brainstem from the thalamus to the medulla oblongata, connecting the cerebral hemispheres.

circulatory system see circulatory system.

client system in the general systems framework and theory of goal attainment, the composite of physiological, psychological, sociocultural, and developmental variables that make up the total person.

colloid system (colloidal system) colloid (def. 3).

conduction system (conductive system (of heart)) the system of atypical cardiac muscle fibers, comprising the sinoatrial and atrioventricular nodes, internodal tracts, atrioventricular bundle, bundle branch, and terminal ramifications into the Purkinje network.

digestive system see digestive system.

Emergency Medical Services (EMS) system a comprehensive program designed to provide services to the patient in the prehospital setting. The system is activated when a call is made to the EMS operator, who then dispatches an ambulance to the patient. The patient receives critical interventions and is stabilized at the scene. A communication system allows the health care workers at the scene to contact a trauma center for information regarding further treatment and disposition of the patient, followed by transportation of the patient to the most appropriate facility for treatment.

endocrine system the system of ductless glands and other structures that produce internal secretions (hormones) that are released directly into the circulatory system, influencing metabolism and other body processes; see endocrine glands.

environmental control system environmental control unit.

expert system a set of computer programs designed to serve as an aid in decision making.

extrapyramidal system see extrapyramidal system.

gateway system a software interface between an online searcher and one or more search systems, facilitating the use of the system by searchers who are unfamiliar with it, or with online retrieval in general.

genitourinary system the organs concerned with production and excretion of urine, together with the reproductive organs. (See Plates.) Called also urogenital system.

haversian system a haversian canal and its concentrically arranged lamellae, constituting the basic unit of structure in compact bone (osteon).

Haversian system: Structures of compact and spongy bone with the central haversian canal surrounded by the lamellae. From Applegate, 2000.

health care system see health care system.

heterogeneous system a system or structure made up of mechanically separable parts, as an emulsion or suspension.

His-Purkinje system the intraventricular conduction system from the bundle of His to the distal Purkinje fibers, which carries the impulse to the ventricles.

Home Health Care Classification system see home health care classification system.

homogeneous system a system or structure made up of parts that cannot be mechanically separated, as a solution.

hypophyseoportal system (hypophysioportal system) (hypothalamo-hypophysial portal system) the venules connecting the hypothalamus with the sinusoidal capillaries of the anterior lobe of the pituitary gland; they carry releasing substances to the pituitary.

immune system see immune system.

interpersonal system in the general systems framework and theory of goal attainment, two or more individuals interacting in a given situation.

lay health system a system comprising an informal referral network and sources of treatment outside the formal biomedical sources of health care; it includes individual consultation and information-seeking through significant others and peers concerning health behaviors, symptoms, and evaluation of treatment before, during, and after consultation with health care professionals.

legal system in the omaha system, anything connected with law or its administration; it includes legal aid, attorney, courts, or Child Protective Services (CPS), and many other agencies and officials.

limbic system a system of brain structures common to the brains of all mammals, comprising the phylogenetically old cortex (archipallium and paleopallium) and its primarily related nuclei. It is associated with olfaction, autonomic functions, and certain aspects of emotion and behavior.

lymphatic system see lymphatic system.

lymphoid system the lymphoid tissue of the body, collectively; it consists of primary (or central) lymphoid tissues, the bone marrow, and thymus, and secondary (or peripheral) tissues, the lymph nodes, spleen, and gut-associated lymphoid tissue (tonsils, Peyer's patches).

lymphoreticular system the lymphoid and reticuloendothelial systems considered together; see also lymphoreticular disorders.

metric system see metric system.

mononuclear phagocyte system the group of highly phagocytic cells that have a common origin from stem cells of the bone marrow and develop circulating monocytes and tissue macrophages, which develop from monocytes that have migrated to connective tissue of the liver (kupffer's cells), lung, spleen, and lymph nodes. The term has been proposed to replace reticuloendothelial system, which includes some cells of different origin and does not include all macrophages.

nervous system see nervous system.

nursing system in the self-care model of nursing, all the actions and interactions of nurses and patients in nursing practice situations; nursing systems fall into three categories: wholly compensatory, partly compensatory, and supportive-educative.

Omaha system see omaha system.

oxygen delivery system a device that delivers oxygen through the upper airways to the lungs at concentrations above that of ambient air. There are two general types: the fixed performance or high flow type, which can supply all of the needs of a patient for inspired gas at a given fractional inspired oxygen; and the variable performance or low flow type, which cannot supply all of the patient's needs for oxygen and delivers fractional inspired oxygen that varies with ventilatory demand.

parasympathetic nervous system see parasympathetic nervous system.

peripheral nervous system the portion of the nervous system consisting of the nerves and ganglia outside the brain and spinal cord.

personal system in the general systems framework and theory of goal attainment, the unified self, a complex whole that is rational, conscious, and feeling and that sets goals and decides on the means of achieving them.

pituitary portal system hypothalamo-hypophysial portal system.

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 (the hypothalamo-hypophysial portal system) or the liver (the hepatic portal circulation).

renin-angiotensin-aldosterone system see renin-angiotensin-aldosterone system.

respiratory system the group of specialized organs whose specific function is to provide for the transfer of oxygen from the air to the blood and of waste carbon dioxide from the blood to the air. The organs of the system include the nose, the pharynx, the larynx, the trachea, the bronchi, and the lungs. See also respiration and Plates 7 and 8.

reticular activating system see reticular activating system.

reticuloendothelial system see reticuloendothelial system.

safety system see safety system.

SI system see SI units.

skeletal system see skeletal system.

social system in the general systems framework and theory of goal attainment, an organized boundary system of social roles, behaviors, and practices developed to maintain balance for growth, development, and performance, which involves an exchange of energy and information between the person and the environment for regulation and control of stressors.

support system in the omaha system, the circle of friends, family, and associates that provide love, care, and need gratification; it may include church, school, workplace, or other groupings.

sympathetic nervous system see sympathetic nervous system.

Unified Medical Language system see unified medical language system.

Unified Nursing Language system see unified nursing language system.

unit dose system a method of delivery of patient medications directly to the patient care unit. Following review by a nurse, a copy of the physician's original order is sent to the pharmacy, where the pharmacist reviews it again. The pharmacist then fills the order and delivers the medication to the patient care unit, usually in a 24-hour supply. Each patient has an individual supply of medications prepared and labeled by the pharmacist.

urinary system the system formed in the body by the kidneys, ureters, urinary bladder, and urethra, the organs concerned in the production and excretion of urine.

urogenital system genitourinary system.

vascular system circulatory system.

vasomotor system the part of the nervous system that controls the caliber of the blood vessels.

---

metric system,

n See system, metric.

---

metric

1. of or pertaining to the metric system.

2. pertaining to measures or measurement.

3. having the meter as a basis.

---

metric system

the system of units of measurement that is based on the meter, gram and liter, and in which new units are formed by prefixes denoting multiplication by a power of ten. See also Tables 4.1-4.6.