Déplacement Moyenne Méthode Définition

Salinité Concentration de sels dissous dans un échantillon d'eau. Mesuré comme la quantité totale de sels dissous en parties pour mille. L'eau de mer a une salinité moyenne d'environ 34 parts pour mille. Salinisation Processus pédogénique qui concentre les sels à la surface du sol ou à proximité, car l'évapotranspiration dépasse largement les apports d'eau provenant des précipitations. Sel (1) Le chlorure de sodium minéral. (2) Composés qui sont produits à la suite d'un atome de métal remplaçant un atome d'hydrogène dans un acide. Salaison Transport de sédiments initié par le déplacement de l'air ou de l'eau où les particules se déplacent d'une surface de repos au milieu de transport en cycles continus répétés rapides. Marais salin Écosystème des zones humides côtières qui est inondé pendant une certaine période de temps par l'eau de mer. Les plantes qui existent dans cette communauté ont une adaptation spéciale pour survivre en présence de salinités élevées dans leur environnement immédiat. Généralement, trouvé vers le pôle de 30deg Nord et Sud latitude. Intrusion de l'eau de mer L'invasion de l'eau salée dans les aquifères d'eau douce dans les zones côtières et intérieures. Cette condition peut être causée par l'eau souterraine. Qui charge l'aquifère, est retiré plus rapidement qu'il est rechargé par la précipitation. Exemple Un échantillon est un groupe de sous-ensembles de données sélectionnées dans un groupe de population plus important. La plupart des échantillons sont tirés au hasard pour garantir une représentation égale dans les données. Sable Particule minérale d'une taille comprise entre 0,06 et 2,0 millimètres de diamètre. Voir aussi l'argile et le limon. Dune de sable Une colline ou une crête de dépôts de sable éolien avec une hauteur minimale de moins d'un mètre et une hauteur maximale d'environ 50 mètres. Trouvé dans les déserts chauds et le long des côtes sablonneuses. Sand Sea Une grande région de sable et de dunes de sable dans un désert. Commun aux déserts erg. Feuille de sable Dépôt de sable stratifié parfois moins bien trié qui ressemblent presque aux dunes. Commun dans le nord de l'Europe. Croyez-vous à la forme lorsque les matériaux soufflés par le vent s'installent sur des zones de neige ponctuée. Grès Un type de roche sédimentaire qui contient une grande quantité de grains de quartz altérés. Ondulations de sable Un autre terme utilisé pour les ondulations de vent. Sand Wedge Une forme de coin de glace qui contient des accumulations de sable soufflé par le vent dans de longues couches verticales. Forme de glace au sol périglaciaire. Vent de Santa Ana Un chinook chaud et sec comme le vent qui se produit dans le sud de la Californie. Originaire de l'est sur un plateau élevé en désert. Taux d'abandon adiabatique saturé (SALR) Taux de déclin de la température d'un paquet ascendant d'air après qu'il a atteint la saturation. Ce taux est inférieur au taux d'écoulement adiabatique sec (9,8 degrés Celsius par 1000 mètres) en raison de l'énergie calorifique ajoutée à la parcelle d'air ascendante par les procédés de condensation et de dépôt. Saturation Conditions atmosphériques où l'eau change sa phase en liquide ou en solide. A saturation, l'humidité relative est de 100, à moins qu'il y ait une pénurie de noyaux de dépôt ou de noyaux de condensation. Généralement, ce processus est causé par le refroidissement de l'atmosphère. Saturation Rapport de mélange Masse de vapeur d'eau qu'un kilogramme d'air sec peut contenir à saturation. Mesuré en grammes. Savane Une communauté de plantes tropicales ou subtropicales, caractérisée par des arbres et des arbustes disséminés parmi une couverture d'herbes et de plantes fourragères. Le climat d'une savane est tropical avec une saison sèche qui se produit dans la période de soleil faible de l'année. Échelle Taille ou étendue relative ou proportionnelle spécifique d'un phénomène mesuré dans l'espace et / ou le temps. Scarification Mouvements importants du sol. Sédiment. Et le matériel de roche causé par des humains. Scattering (atmosphérique) C'est un processus atmosphérique où les petites particules et les molécules de gaz diffusent une partie du rayonnement solaire entrant dans des directions aléatoires sans aucune altération de la longueur d'onde de l'énergie électromagnétique. Cependant, la diffusion réduit la quantité de rayonnement entrant atteignant la surface de la Terre. Une proportion importante des rayonnements solaires dispersés est redirigée vers l'espace. La quantité de diffusion qui se déroule dépend de deux facteurs: la longueur d'onde du rayonnement entrant et la taille de la particule de diffusion ou de la molécule de gaz. Dans l'atmosphère terrestre, la présence d'un grand nombre de particules d'une taille d'environ 0,5 micromètre donne des longueurs d'onde plus courtes préférentiellement dispersées. Ce facteur fait aussi que notre ciel paraisse bleu car cette couleur correspond aux longueurs d'onde les mieux diffusées. Scavenger Organisme hétérotrophe qui consomme principalement des animaux morts ou des parties d'animaux morts pour la nourriture. Ces organismes ne tuent pas leurs aliments. Des exemples de carnivores comprennent les mouches, les diverses espèces de vautours, les crabes et les hyènes. Voir aussi herbivore. Detritivore. Omnivore Et carnivore. Schiste Une roche métamorphique de grain moyen à grossier, avec des plans de litière bien développés dérivés de la recrystrallisation foliaire de minéraux comme le mica. Science La science est un moyen d'acquérir des connaissances. Pour faire de la science, il faut suivre une méthodologie universelle spécifique. Le thème central de cette méthodologie est le test d'hypothèses et la capacité de faire des prédictions. L'objectif général de la science est de mieux comprendre la nature et notre Univers. Méthode scientifique L'approche que la science utilise pour acquérir des connaissances. Cette méthode essaie d'être unbias et neutre. Implique le raisonnement inductif et déductif, le test d'hypothèse et la falsification. Et le test de modèle prédictif. Végétation sclérophylle Terme utilisé pour décrire la végétation résistante à la sécheresse, fréquente dans les climats méditerranéens. Quelques adaptations communes à ce type de végétation sont: les racines profondes, la surface foliaire réduite à l'atmosphère et les feuilles épaisses et cireuses avec des stomates de fermeture qui résistent à la perte d'eau. Scour (1) Se réfère à la puissance érosive de l'eau. (2) Effets abrasifs des roches et des sédiments incorporés dans la base de glace d'un glacier. Scree Une accumulation de fragments de roche altérés à la base d'une pente rocheuse abrupte ou d'une falaise. Mer (1) Corps d'eau salée trouvé sur la surface continentale de la Terre. (2) Une partie d'un océan qui est à proximité immédiate d'un continent. Sea Arch Un relief côtier composé d'une roche qui ressemble à un arc. Ces reliefs sont créés lorsque les vagues s'érodent à travers un bout mince des deux côtés. Sea Breeze Modèle local de circulation thermique trouvé à l'interface entre la terre et l'eau. Dans ce système de circulation, les vents de surface soufflent de l'eau à la terre pendant la journée. Épandage du plancher océanique Le processus de création de la croûte océanique et le mouvement du fond marin qui se produit au niveau de la crête mi-océanique. Sea-Level L'élévation de surface moyenne des océans des mondes. Pression au niveau de la mer Pression atmosphérique moyenne au niveau de la mer. Cette valeur est de 1013,2 millibars. Seamount Une montagne volcanique trouvée sur un bassin océanique qui a une origine non liée à une crête mi-océanique ou une zone de subduction tectonique. Fumée de mer Voir brouillard d'évaporation. Saisons Périodes de temps généralement basées sur les variations de l'intensité et de la durée de la lumière solaire reçues aux latitudes moyenne et élevée. Quatre saisons sont normalement reconnues: printemps été automne et hiver. La définition astronomique est plus précise et suggère les périodes suivantes pour les quatre saisons: Printemps - 22 mars au 21 juin Été - 22 juin au 22 septembre Automne - 23 septembre au 22 décembre et hiver - 23 décembre au 21 mars. Pile maritime A Pente raide de roche située dans l'océan à une courte distance de la côte. Ces reliefs sont créés lorsque les vagues s'érodent à travers un bout mince des deux côtés. Seaward Positionné ou situé loin de la terre, mais vers un océan ou la mer. Eau de mer Le mélange d'eau et de divers sels dissous trouvés dans les mondes océans et mers. Carnivore secondaire Voir consommateur tertiaire. Secondary Consumer Organismes qui occupent le troisième niveau trophique dans la chaîne alimentaire du pâturage. Ces organismes sont des carnivores. Aussi connu comme un carnivore primaire. Polluant secondaire Polluants atmosphériques créés chimiquement dans l'atmosphère lorsque des polluants primaires et d'autres composants de l'air réagissent. Voir aussi le polluant primaire. Substance secondaire Produit chimique organique produit par une plante qui n'a aucune fonction directe dans son métabolisme. Beaucoup de ces produits chimiques sont toxiques et sont censés être créés par la plante pour réduire les dommages herbivores ou les effets négatifs de la concurrence par d'autres plantes. Succession secondaire Succession sur une surface préalablement végétalisée. Le sol ou le substrat sur cet emplacement contient une banque de semences active. Onde secondaire Voir onde S ou onde de cisaillement. Forêt de deuxième croissance Forêt de forêt qui est le résultat de la succession secondaire. Deuxième loi de la thermodynamique Cette loi stipule que la chaleur ne peut jamais passer spontanément d'un plus froid à un corps plus chaud. De ce fait, les processus naturels impliquant le transfert d'énergie doivent avoir une direction, et tous les processus naturels sont irréversibles. Cette loi prévoit également que l'entropie d'un système isolé augmente toujours avec le temps. Ségumérine Cette plante, semblable à l'herbe, est adaptée pour pousser dans des habitats humides. Sédiments Matières solides qui ont été ou sont érodées. Transportés. Et déposé. Le transport peut être dû au transport fluvial. Marins, glaciaires ou éoliens. Roches sédimentaires formées par le dépôt. La modification et / ou la compression et la lithisation de débris rocheux altérés, de précipités chimiques ou de sédiments organiques. Voir aussi les roches sédimentaires clastiques vs non-clastiques. Courbe d'estimation des sédiments Expression numérique ou courbe graphique qui décrit la relation quantitative entre la décharge de l'écoulement et le sédiment transporté par un ruisseau particulier. Semence Ovule fécondé d'une plante qui contient un embryon et des produits alimentaires pour la germination. Une fois germé, l'embryon peut devenir un individu mature. Seed Bank Collection de graines disponibles pour la germination dans le sol. Dispersion des semences Mouvement d'une graine de plante loin de la plante mère par un mécanisme passif ou actif. Seepage (1) Le mouvement progressif de l'eau dans la couche de sol. (2) mouvement lent de l'eau de sous-surface à la surface. Ce flux n'est pas assez grand pour l'appeler un ressort. Seepage Lake Un lac dont l'eau provient principalement de l'infiltration d'eau souterraine. Glace ségrégée Une forme de glace broyée periglaciaire qui se compose de glace presque pure qui existe souvent comme une couche horizontale étendue. La couche de glace se développe en raison de la migration active de l'eau autour de la caractéristique. Ces caractéristiques se trouvent juste au-dessous de la couche active. Seif (1) Une grande dune de sable qui est allongée dans la direction générale des vents dominants. (2) Une dune de sable formée par des vents de multiples directions. Secousses sismiques déplacement habituellement causé par un tremblement de terre. Vague sismique Déplacement successif de la roche ordinairement causé par un tremblement de terre. Sismographe Instrument qui mesure l'énergie contenue dans les ondes sismiques d'un tremblement de terre ou d'un autre type de déplacement du sol. Sismologie Une branche de la science s'est concentrée sur l'étude des séismes et de l'activité sismique. Autorégulation La capacité de certains systèmes à maintenir un équilibre à l'état d'équilibre grâce à des rétroactions positives et négatives. Marée semi-diurne marées qui ont deux haute et deux basses eaux par période de marée. Chaleur sensible Chaleur qui peut être mesurée par un thermomètre et ainsi détectée par les humains. Flux de chaleur sensible Processus dans lequel l'excès d'énergie thermique est transféré dans l'atmosphère. Le processus implique d'abord le déplacement de l'énergie thermique de la surface de la Terre vers l'atmosphère par conduction et convection. L'énergie thermique peut alors se déplacer horizontalement advection (circulation atmosphérique). Un de deux jours pendant une année où la déclinaison du Soleil est à l'équateur. L'équinoxe de septembre indique le premier jour de chute dans l'hémisphère nord. Dans l'hémisphère sud, cette date marque le premier jour du printemps. Durant l'équinoxe de septembre, tous les emplacements sur la Terre (sauf les pôles) sont égaux (12 heures) jour et nuit. L'équinoxe de septembre se produit soit le 22 ou le 23 septembre. Reproduction sexuelle Tout processus de reproduction qui implique la fusion des gamètes. Shale Roche sédimentaire à grains fins composée de particules d 'argile lithifiée. Stress de cisaillement Stress provoqué par des forces opérant parallèlement les unes aux autres mais dans des directions opposées. Onde de cisaillement Onde sismique qui crée un mouvement ressemblant à une onde perpendiculaire à la direction de propagation de l'énergie sismique. Également appelé S-wave. Flux de feuille Voir écoulement par terre. Feuille Une forme d'altération physique de la roche où les feuilles superficielles du matériau se cassent et s'éfolient en raison de la libération de pression. Voir aussi le dôme d'exfoliation. Sheetwash L'élimination des matériaux de surface lâche par écoulement terrestre. Processus d'érosion. Bouclier Une grande zone stable de roches ignées et métamorphiques exposées très anciennes (plus de 600 millions d'années) sur les continents. Cette roche forme le noyau des continents. Shield Volcano Volcano créé à partir de couches alternatives de coulées de lave. Les volcans de bouclier sont légèrement inclinés avec un gradient entre 6 et 12 degrés. Leur hauteur peut atteindre 9000 mètres. La chimie du magma de ces volcans est basaltique. Shore La zone de terre bordant un corps d'eau relativement grand comme un lac ou un océan. Shoreline Ligne qui sépare une surface terrestre d'un plan d'eau. Voir aussi le littoral. Onde courte Une petite vague dans le courant de jet polaire et les vents d'ouest qui s'étendent du milieu à la troposphère supérieure. Souvent associé à la formation d'un cyclone de latitude moyenne à la surface du sol. Contraste avec les vagues longues. Rayonnement à ondes courtes Rayonnement électromagnétique avec une longueur d'onde comprise entre 0,1 et 0,7 micromètre (microm). Couramment utilisé pour décrire le rayonnement émis par le Soleil. Arbuste Une plante ligneuse qui est plus petite qu'un arbre. Les arbustes n'ont généralement pas de coffre. Couche Sial La partie de la croûte qui forme les continents et est composée de roches granitiques relativement légères. Siberian High Système de haute pression qui se développe en hiver sur le nord de l'Asie centrale. Sidereal Day Temps qu'il faut pour achever une rotation de la Terre par rapport à la position d'une étoile fixe. Cette mesure dure 23 heures, 56 minutes et 4,09 secondes. Comparer avec le jour solaire moyen. Silice minérale qui est composé de dioxyde de silicium, SiO 2. Silicate Groupe de minéraux qui ont des structures cristallines à base d'un tétraèdre de silice (SiO 4). Silicate Magma Magma qui est felsic dans la composition. Silcrets S roche édifiante créée par la précipitation chimique de la silice. Sill Les plans horizontaux de la roche ignée qui fonctionnent parallèlement au grain des dépôts de roche originaux. Ils se forment quand le magma entre et refroidit dans les plans de lissage trouvés dans la croûte. Voir aussi la roche ignée intrusive. Silt Particule minérale de taille comprise entre 0,004 et 0,06 millimètres de diamètre. Voir aussi l'argile et le sable. Siltstone Roche sédimentaire à grains fins composée de particules de limon lithifié. Silurian période géologique qui a eu lieu environ 408 à 438 millions d'années. Pendant cette période, les premières espèces de plantes et d'insectes apparaissent. Sima Layer La partie de la croûte qui forme les bassins océaniques et les couches inférieures dans la croûte et est composée de roches basaltiques relativement lourdes. Évier (1) Site de stockage de certains matériaux. (2) Un autre nom pour sinkhole. Sinkhole Une fosse comme le trou trouvée dans les zones de karst. Ces caractéristiques sont causées par l'altération du calcaire ou de la dolomie par le drainage souterrain. Aussi appelé un lavabo ou doline. Projection sinusoïdale de la zone égale Projection cartographique qui représente les zones sous leur forme réelle sur une carte bidimensionnelle. Les distances ne sont correctes que le long des parallèles et du méridien central. Les formes deviennent plus distordues du méridien central et proches des pôles. Élimination Voir mouillage et séchage. Slate Une roche métamorphique à grain fin avec des plans de couchage bien développés dérivés de la légère recrystrallisation des schistes. Trémie Voir pellets de glace. Sling Psychromètre Psychromètre qui utilise une poignée tournante et un mouvement tourbillonnant pour ventiler son thermomètre à bulbe humide. Slip-Face Le côté lee d'une dune où le matériau s'accumule et glisse ou roule vers le bas. Slope Aspect Direction de la boussole (Nord, Nord Est, Est, Sud Est, Sud, Sud Ouest, Ouest et Nord Ouest). Échec de la pente Le mouvement descendant du sol et des sédiments par des processus de mouvement de masse. Slump Voir glissement de rotation. Petit cercle Un cercle sur la surface des globes qui ne coupe pas le centre de la Terre. Les parallèles de latitude sont des exemples de petits cercles. Smog Terme générique utilisé pour décrire les mélanges de polluants dans l'atmosphère. Voir aussi le smog industriel et le smog photochimique. Snout Avant d'un glacier. Aussi appelé le terminus. Neige Type de précipitation solide qui se forme dans les nuages ​​avec une température de l'air inférieure au point de congélation. La neige se forme lorsque la vapeur d'eau se dépose directement sous la forme d'un solide sur un noyau de dépôt. Les flocons de neige commencent leur vie sous la forme de très petits cristaux se développant sur des noyaux de dépôt hexagonal à six côtés. Le flocon de neige en développement, puis croît plus vite aux six points des noyaux que ces surfaces sont plus exposés à la vapeur d'eau atmosphères. Les chutes de neige sont plus fréquentes avec le soulèvement frontal associé à des cyclones de moyenne latitude pendant les mois d'automne, d'hiver et de printemps, lorsque la température de l'air est inférieure à zéro. Snowfield Zone d'accumulation permanente de neige. Généralement à haute altitude ou latitudes. Ligne de neige Altitude ou limite latitudinale séparant les zones où la neige ne fond pas pendant la saison estivale dans les zones où elle se trouve. Similaire à la notion de limite ferme, sauf qu'elle ne se limite pas aux glaciers. Neige fondue Conversion de la neige dans le ruissellement et l'écoulement des eaux souterraines avec l'apparition de températures plus chaudes. Pellets de neige Une forme de précipitation connue sous le nom de graupel. Les granules de neige sont des morceaux de glace blancs, sphériques, d'un diamètre maximal de 5 millimètres. Les pellets de neige se développent lorsque les gouttelettes surgelées gèlent sur les flocons de neige. Les granulés de neige tombent souvent pendant une brève période lorsque la précipitation se transforme des granulés de glace en neige. Les granulés de neige peuvent être facilement distingués des flocons de neige emballés car ils ont tendance à rebondir quand ils frappent le sol. Les flocons de neige emballés ne sont pas suffisamment denses pour les faire rebondir. Sol Couche de matière non consolidée trouvée à la surface de la Terre qui a été influencée par les facteurs formant le sol: le climat, le relief, le matériau parental, le temps et les organismes. Le sol se compose normalement de particules minérales altérées, de matières organiques mortes et vivantes. L'espace aérien et la solution du sol. Colloïdes du sol Très petites particules organiques et inorganiques se trouvant dans un sol. Les colloïdes inorganiques sont souvent des particules d'argile. Les colloïdes du sol portent une charge électrique négative et sont les principaux sites d'échange de cations. Les colloïdes du sol contiennent de grandes quantités d'éléments et de composés qui sont utilisés par les plantes pour la nutrition. Creep du sol Mouvement de masse lente du sol descendant. Se produit lorsque les contraintes sur le matériau de la pente sont trop petites pour créer une défaillance rapide. Erosion du sol Transport de particules minérales de sol et de matières organiques par le vent, l'eau courante, ou les deux. Les activités humaines qui perturbent la surface du sol ou enlèvent la végétation peuvent améliorer ce processus naturel. Fertilité du sol La capacité d'un sol à fournir des nutriments pour la croissance des plantes. Flux de chaleur du sol La vitesse d'écoulement de l'énergie thermique dans le sol, à partir du sol ou à travers celui-ci. Horizon du sol Couche dans un profil de sol qui diffère physiquement, biologiquement ou chimiquement des couches au-dessus ou au-dessous. Recharge de l'humidité du sol Processus de remplissage de l'espace poreux dans un sol (entreposage). Matière organique du sol Composants organiques du sol. Perméabilité du sol La vitesse à laquelle l'eau et l'air se déplacent verticalement à travers un sol. Porosité du sol Le volume d'eau qui peut être retenu dans un sol. Se réfère également au rapport entre le volume des vides et le volume total du sol. Profil du sol Disposition verticale des couches ou des horizons dans un sol. Soil Science L'étude des sols dans une perspective interdisciplinaire. Solution de sol Liquide aqueux trouvé dans un sol. Ce liquide contient normalement des ions libérés à partir de particules minérales, de matière organique ou de racines et de feuilles végétales. Structure du sol Terme général qui décrit comment les minéraux et les particules de matière organique sont organisés et regroupés dans un sol. Taxonomie des sols La classification d'un sol dans un système hiérarchique basé sur ses différentes propriétés. Le regroupement va du général au spécifique. Texture du sol Les quantités relatives des différents types et tailles de particules minérales dans un sol. Eau du sol L'eau trouvée occupant les espaces poreux entre les particules de sol. Altitude Solaire Hauteur du Soleil au-dessus de l'horizon du Nord Vert ou du Sud Vert. Solar Constant Terme utilisé pour décrire la quantité moyenne d'insolation solaire reçue par une surface horizontale au bord de l'atmosphère terrestre. Cette valeur est d'environ 1370 watts par mètre carré. Jour solaire Temps requis pour que la Terre accomplisse une rotation par rapport au Soleil. Énergie solaire Voir insolation. Solar Noon Point du temps pendant la journée où le Soleil est aligné avec le Nord Vrai et le Sud Vrai. Rayonnement solaire Rayonnement électromagnétique qui provient du Soleil. La plupart des rayons Suns sont émis à des longueurs d'onde entre 1,0 et 0,1 microns (microm). Voir aussi l'insolation. Rayonnement solaire direct. Et le rayonnement solaire diffus. Système solaire La collection de corps célestes qui orbitent autour du Soleil. Solar Wind Masse de gaz ionisé émis vers l'espace par le Soleil. Joue un rôle dans la formation des aurores. Année solaire Le temps qu'il faut à la Terre pour faire une orbite autour du Soleil. C'est environ 365.2422 jours. Solide Un état de la matière où les molécules où la masse de la substance n'a pas la propriété de l'écoulement. Solifluction Forme de mouvement de masse dans des environnements qui connaissent une action de gel-dégel. Il se caractérise par le mouvement lent de la pente vers le bas du sol et la formation de caractéristiques en forme de lobe. Voir aussi gelifluction. Solonetzic Terre Ordre du sol (type) du système canadien de classification des sols. Ce type de sol est associé à des habitats de prairies où des niveaux élevés d'évapotranspiration provoquent l'accumulation de sels à la surface du sol ou à proximité. Ces sols sont fréquents dans les régions sèches des Prairies où l'évapotranspiration dépasse de beaucoup les précipitations. Solstice Dates où la déclinaison du Soleil est à 23.5deg Nord ou Sud de l'équateur. Pour l'hémisphère Nord, cette date tombe le 21 ou le 22 juin (solstice d'été). Dans l'hémisphère sud, la date est le 21 ou 22 décembre (solstice d'hiver). Solum Partie du sol qui est capable de soutenir la vie. Solution (1) Forme de l'altération chimique où les roches et les minéraux sont dissous par l'eau. Les matériaux entrant dans le mélange peuvent altérer la nature chimique de la solution et peuvent augmenter la résistance de cet agent de vieillissement. Par exemple, le mélange de dioxyde de carbone et d'eau peut former de l'acide carbonique. (2) La dissolution d'une substance dans un liquide. Source Région Région où les masses d'air proviennent et viennent à posséder leurs caractéristiques d'humidité et de température. Southeast Trade Winds Voir les alizés. Oscillation australe Inversion de la circulation atmosphérique dans l'océan Pacifique tropical qui déclenche le développement d'un El Nio. Emplacement du pôle magnétique sud dans l'hémisphère sud où les lignes de force du champ magnétique terrestre sont verticales. Ce point sur la Terre change graduellement sa position avec le temps. Pôle Sud Position de surface définie par l'intersection de l'axe polaire avec la surface terrestre dans l'hémisphère sud. Cet emplacement a une latitude de 90deg Sud. Espace (1) Une distance, une zone ou un volume. (2) Une zone tridimensionnelle infinie dans laquelle les objets ont des coordonnées relatives les uns aux autres. (3) La région au-delà des limites extérieures de l'atmosphère terrestre. Analyse spatiale L'examen du modèle spatial des phénomènes naturels et des phénomènes anthropiques à l'aide de l'analyse numérique et des statistiques. Isolation spatiale Isolation reproductive de deux populations ou plus d'une espèce par la distance ou des barrières physiques. Pendant de longues périodes, l'isolement géographique conduit à la spéciation par une évolution divergente en raison de l'hétérogénéité de l'environnement. Également appelé isolement géographique. Tradition spatiale Tradition académique dans la géographie moderne qui étudie les phénomènes géographiques dans une perspective strictement spatiale. Espèces spécialisées Espèces ayant une niche écologique relativement étroite. Ces espèces peuvent être capables de vivre dans un seul type d'habitat, ne tolérer que des conditions environnementales spécifiques ou utiliser seulement quelques types d'aliments. Spécification Processus par lequel de nouvelles espèces proviennent de mutations. sélection naturelle . Et l'évolution. Espèces (1) Les différents types d'organismes trouvés sur la Terre tels que définis par classification taxonomique ou phylogénique. (2) Groupe d'organismes de croisement qui ne se reproduisent habituellement pas avec des membres d'autres groupes. Association des espèces Un groupe particulier d'espèces dans une zone. Espèce Diversité Nombre d'espèces différentes dans une région donnée. Densité Le rapport de la masse d'un corps à la masse d'un volume d'eau identique à une température spécifique. Chaleur spécifique La capacité calorifique d'une masse unitaire d'une substance ou d'une chaleur nécessaire pour élever la température de 1 gramme (g) d'une substance 1 degré Celsius. Humidité spécifique Mesure de l'humidité atmosphérique. L'humidité spécifique est la masse de vapeur d'eau dans une masse d'air donnée. Normalement exprimé en grammes de vapeur d'eau par kilogramme d'air à une température spécifique. Spectrum Est un graphique qui décrit la quantité de rayonnement qui est émise par un corps à des longueurs d'onde particulières. Vitesse de la lumière Vitesse de la lumière dans le vide. Cette vitesse est d'environ 3 x 10 8 mètres par seconde. Il prend la lumière du soleil 8 minutes et 20 secondes pour atteindre la Terre. Métallisation sphéroïdale Type d'intempéries chimiques sous terre, où les angles des roches jointes deviennent arrondis au fil du temps. La roche change de forme rectangulaire à plus ronde. Spit Une accumulation longue et étroite de sable et / ou de gravier qui se projette dans un corps d'eau océanique. Ces caractéristiques résultent du dépôt de sédiments par la dérive de la côte. Spodosols Ordre du sol (type) du Système de classification des sols du Service de conservation des ressources naturelles des États-Unis. Un sol spodosol a des couches prononcées d'illuviation caractérisé par des accumulations d'oxydes de fer et d'aluminium dans l'horizon B. Ces sols se forment dans des climats humides et frais. Permafrost sporadique Forme du pergélisol qui existe sous forme de petites îles de sol gelé dans des sols et des sédiments autrement dégelés. SPOT (Centre National dEtudes Spatiales) Série de satellites développés par l'Agence Spatiale Française, avec la collaboration de la Belgique et de la Suède pour le suivi à distance des ressources sur Terre. Le premier satellite SPOT a été lancé en 1986. Voir le site Web suivant pour plus d'informations - SPOT Image. Printemps (1) Saison entre l'hiver et l'été. Astronomiquement c'est la période de l'équinoxe vernal au solstice d'été dans l'hémisphère Nord. (2) Un écoulement naturel de l'eau de la sous-surface à la surface. Il se produit généralement lorsque la nappe phréatique intersecte la surface terrestre. Spring Tide Tide qui se produit tous les 14 à 15 jours et coïncide avec la nouvelle et la pleine lune. Cette marée a une grande marée, car les forces gravitationnelles de la lune et du Soleil sont complémentaires les unes des autres. Contraste avec la marée neap. Squall Line Une bande de développement d'orage se trouve devant un front froid. Stabilité La capacité d'un système à tolérer ou à se remettre d'une perturbation ou d'un stress environnemental. Atmosphère stable Condition dans l'atmosphère où les parcelles d'air isolées ont tendance à couler. Les parcelles d'air ont tendance à être plus fraîches que l'air qui les entoure. Equilibre stable Dans un équilibre stable, le système affiche des tendances à revenir au même équilibre après perturbation. Moraine stadiale Voir la moraine rénale. Étape L'élévation de la surface de l'eau dans un cours d'eau. Pression atmosphérique standard Pression de 101,32 kilopascals ou 1013,2 millibars. Écart-type Mesure statistique de la dispersion des valeurs d'observation dans un ensemble de données. Calculé en déterminant la racine carrée de la variance. Star Un corps céleste grand et très massif, auto-lumineux, qui illumine par le rayonnement provenant de sa source d'énergie interne. Amidon Complexe hydrate de carbone composé de milliers d'unités de glucose. Composé principal que les plantes utilisent pour stocker leur énergie alimentaire. État de la question Forme de la question. La matière peut exister sous trois formes différentes de gaz. liquide . Et solide. Équilibre statique L'équilibre statique se produit lorsque la force et la réaction sont équilibrées et que les propriétés du système restent inchangées au cours du temps. Front stationnaire Une zone de transition dans l'atmosphère où il ya peu de mouvement de masses d'air opposées et les vents soufflent vers l'avant à partir de directions opposées. Equilibre à l'état d'équilibre Dans ce type d'équilibre, l'état moyen du système reste inchangé dans le temps. Brouillard de vapeur Voir brouillard d'évaporation. Stemflow Est le processus qui dirige la précipitation vers le bas des branches des plantes et des tiges. La redirection de l'eau par ce processus provoque la surface du sol autour de la tige des plantes pour recevoir une humidité supplémentaire. La quantité de tige est déterminée par la forme des feuilles et l'architecture des tiges et des branches. En général, les arbres à feuilles caduques ont plus de tige que de conifères. Stefan-Boltzmann Law Cette loi de rayonnement suggère que la quantité de rayonnement émis par un corps est proportionnelle à la 4e puissance de sa température mesurée en unités Kelvin. Cette loi peut être exprimée par l'équation simple suivante: E s T 4 où E est la quantité de rayonnement émis par le corps en Watts par mètre carré, s est une constante égale à 0,0000000567 et T est la température du corps à Kelvins . Steppe Terme russe pour les prairies de latitudes moyennes. Stoma (pl. Stomata) Petite ouverture à la surface d'une plante qui est utilisée pour l'échange gazeux. Storm Surge Relativement rapide montée de la hauteur de l'océan le long d'un littoral. Souvent causé par les vents d'orage poussant l'eau vers la terre. Storm Track Le chemin emprunté par une tempête (orage, cyclone à moyenne latitude ou ouragan) ou le chemin moyen pris par les tempêtes. Stoss Côté d'une pente qui fait face à la direction de l'écoulement de la glace, du vent ou de l'eau. En face de lee. Dérive stratifiée Type de dérive glaciaire qui a été partiellement triée par l'eau de fonte glaciofluviale. Strates Les couches ou les lits trouvés dans la roche sédimentaire. Stratigraphie Sous-discipline de la géologie qui étudie la séquence, l'espacement, la composition et la répartition spatiale des dépôts sédimentaires et des roches. Nuages ​​de stratocumulus Nuage de couleur grise à basse altitude composé de gouttelettes d'eau qui ont une apparence inégale. Chaque nuage est constitué d'une masse arrondie. Ce nuage a une base un peu uniforme et couvre normalement tout le ciel. Entre les patchs ciel bleu peut être vu. Trouvé dans une gamme d'altitude de la surface à 3.000 mètres. Stratopause La stratopause est une couche de transition atmosphérique relativement mince trouvée entre la stratosphère et la mésosphère. La hauteur de cette couche est d'environ 50 kilomètres au-dessus de la surface de la Terre. Stratosphere Atmospheric layer found at an average altitude of 11 to 50 kilometers above the Earths surface. Within the stratosphere exists the ozone layer . Ozone s absorption of ultraviolet sunlight causes air temperature within the stratosphere to increase with altitude. Stratovolcano See composite volcano . Stratus Clouds Low altitude gray colored cloud composed of water droplets. This cloud has a uniform base and normally covers the entire sky. It is also quite thick and can obscure the Sun. Light precipitation is often found falling from it. Found in an altitude range from the surface to 3,000 meters. Stream A long narrow channel of water that flows as a function of gravity and elevation across the Earths surface. Many streams empty into lakes . seas or oceans . Stream Bank Sides of the stream channel . Stream Bed Bottom of the stream channel . Stream Channel Long trough-like depression that is normally occupied by the water in a stream . Stream Discharge A river or streams rate of flow over a particular period of time. Usually measured by a current meter and expressed in cubic meters per second. Stream discharge depends on the volume and velocity of the flow. Stream Flow The flow of water in a river or stream channel . Stream Gradient The change in elevation from a stream s headwaters to its mouth expressed in degrees, percentage, or as a distance ratio (riserun). Stream Load Refers to the material or sediment carried by a stream . In normally consists of three components: bed load (pebbles and sand which move along the stream bed without being permanently suspend in the flowing water), suspended load ( silts and clays in suspension ) and dissolved load (material in solution ). Stream Order The relative position, or rank, of a stream channel segment in a drainage network . Stream Long Profile Vertical and horizontal profile of the stream . Most streams have a profile that is concave shaped. Striations Grooves of scratches found in surface rock that are the result of glacial abrasion . Strike One of the directional properties of a geologic structure such as a fold or a fault . Strike is the horizontal directional taken by an imaginary line drawn on the plane of the formation. Also see dip . Strike-Slip Fault Fault that primarily displays horizontal displacement. Structural Landform Is a landform created by massive Earth movements due to plate tectonics . This includes landforms with some of the following geomorphic features: fold mountains, rift valleys, and volcanoes. Subatomic Particles Extremely small particles that make up the internal structure of atoms . Subduction ( Tectonic ) Process of plate tectonics where one lithospheric plate is pushed below another into the asthenosphere . Subduction Zone Linear area where tectonic subduction takes place. Sublimation Process where ice changes into water vapor without first becoming liquid. This process requires approximately 680 calories of heat energy for each gram of water converted. Submarine Canyon V-shaped canyons cut into the continental slope to a deep of up to 1200 meters. These features are normally associated with major rivers. Subpolar Glacier Glacier in which the ice found from the its surface to base has a temperature as cold as -30deg Celsius throughout the year. This is well below the pressure melting point . However, melting does occur in the accumulation zone in the summer. One of the three types of glaciers: cold glacier temperate glacier and subpolar glacier . Subpolar Lows Surface zone of atmospheric low pressure located at about 60deg North and South latitude. These low pressure systems are produced by the frontal lifting of subtropical air masses over polar air. Subsea Permafrost Form of permafrost that exists beneath the sea in ocean sediments. Subsidence Lowering or sinking of the Earths surface. Subsolar Point The location on the Earth where the Sun is directly overhead. Also see declination . Subtropical High Pressure Zone Surface zone of atmospheric high pressure located at about 30deg North and South latitude. These high pressure systems produced by vertically descending air currents from the Hadley cell . Subtropical Jet Stream Relatively fast uniform winds concentrated within the upper atmosphere in a narrow band. The subtropical jet stream exists in the subtropics at an altitude of approximately 13 kilometers. This jet stream flows from west to east and has a speed that is somewhat slower that the polar jet stream . Also see jet stream . Succession Directional cumulative change in the types plant species that occupy a given area, through time. Succulent Vegetation Group of plants that have the ability to survive in deserts and other dry climates by having no leaves. Instead their branches and stems that are photosynthetic . This adaptation reduces the surface area for evaporation thus reducing the loss of scarce water. Sugar Type of carbohydrate chemically based on carbon, oxygen, and hydrogen. Sulfur Dioxide A gas produced from volcanic eruptions, ocean spray, organic decomposition and the burning of fossil fuels . Sulfur dioxide is a component in the creation of acid precipitation . This colorless gas has the chemical formula SO 2 . Sulfate Aerosol Type of solid compound commonly found in the atmosphere . These particles play an important role in reflecting . absorbing . and scattering incoming insolation . The source of these compounds is both natural and human-made. Most of the human-made particles come from the combustion of fossil fuels . Sulfuric Acid Acid with the chemical formula H 2 SO 4 . Summer Season between spring and fall . Astronomically it is the period from the summer solstice to the autumnal equinox in the Northern Hemisphere. Summer Solstice The summer solstice denotes the first day of the summer season. For the Northern Hemisphere, the date of summer solstice is either on June 21 or 22 (changes yearly). December 21 or 22 is the date of the summer solstice for the Southern Hemisphere. During the summer solstice, locations in their respective hemispheres experience the longest day of the year. Sun Luminous star around which the Earth and other planets revolve around. The Sun emits 63,000,000 Watts per square meter of electromagnetic radiation . The Sun has an average distance from the Earth of about 150,000,000 kilometers. The Earths orbit is not circular but elliptical. Sunrise Moment of time when the Sun s edge first appears above the Earths horizon . Sunset Moment of time when the Sun s edge completely disappears below the Earths horizon . Sunspot Dark colored region on the Sun that represents an area of cooler temperatures and extremely high magnetic fields. Supercooled Water Cooling of water below 0deg Celsius without freezing. Common in clouds where there is a deficiency of condensation nuclei . Super-Saturation Atmospheric condition where saturation occurs at a relative humidity greater than 100 because of a shortage of deposition or condensation nuclei . Surface Heat Flux Process where heat energy is transferred into land and ocean surfaces on the Earth. Much of this transfer takes place when solar radiation absorbed at the land or ocean surface is converted into heat energy. On land surfaces, surface heat is transfered down into the ground by conduction . Heat energy is transfered to greater depths in ocean surfaces because liquids have the ability mix by convection . Heat energy stored in ocean waters can also move quickly over large horizontal distances in a poleward direction through ocean currents . Surface Creep The sliding and rolling movement of soil particles on the Earths surface because of wind . Eolian process of soil particle movement. Surface Tension Tension of a liquid s surface. Due to the forces of attraction between molecules . Surface Wave Type of seismic wave that travels across the Earths surface. These earthquake generated waves cause the Earths surface to roll or sway like waves on the ocean. Surge A large, destructive ocean wave caused by very low atmospheric pressure and strong winds. Hurricanes often cause a surge of the ocean surface. Suspended Load Portion of the stream load that is carried almost permanently suspended in flowing water. Suspension Erosional movement of sediment continually held in the transport medium of air, water or ice. Sustainable Development Forms of economic growth and other human activities that meet the requirements of the present without jeopardizing the ability of future generations of individuals to meet their own needs. Swash A thin sheet of water that moves up the beach face after a wave of water breaks on the shore . S-Wave A seismic wave that moves material it encounters perpendicular to its direction of travel. This type of seismic wave causes shear stress in the material it moves through. Also called a secondary wave or a shear wave . Swell A relatively smooth ocean wave that travels some distance from the area of its generation. Symbiotic Mutual relationship between two organisms which is necessary for either to survive. Symbiotic Mutualism Mutualistic interaction where the species interact physically and their relationship is biologically essential for survival . Syncline A fold in rock layers that forms a trough-like bend. Synoptic Scale Scale of geographic coverage used on daily weather maps to describe large scale atmospheric phenomenon (for example, mid-latitude cyclone . air masses . fronts . and hurricanes ). System A system is a set of interrelated components working together towards some kind of process. System Attribute A system attribute is the perceived characteristic of a system element . For example, number, size, color, volume, and temperature may be some of the perceived characteristics of clouds in the atmospheric system. System Boundary Outer edge of system . Zone between one system and another system. System Element System elements are the kinds of things or substances composing the system . They may be atoms or molecules, or larger bodies of matter-sand grains, rain drops, plants, or cows. System Relationship Is the association that exist between the elements and attributes of a system based on cause and effect. System State Current value of a systems elements . attributes . andor relationships. Definition Pain is an unpleasant feeling that is conveyed to the brain by sensory neurons. The discomfort signals actual or potential injury to the body. However, pain is more than a sensation, or the physical awareness of pain it also includes perception, the subjective interpretation of the discomfort. Perception gives information on the painx0027s location, intensity, and something about its nature. The various conscious and unconscious responses to both sensation and perception, including the emotional response, add further definition to the overall concept of pain. Description Pain arises from any number of situations. Injury is a major cause, but pain may also arise from an illness. It may accompany a psychological condition, such as depression, or may even occur in the absence of a recognizable trigger. Acute pain Acute pain often results from tissue damage, such as a skin burn or broken bone. Acute pain can also be associated with headaches or muscle cramps. This type of pain usually goes away as the injury heals or the cause of the pain (stimulus) is removed. To understand acute pain, it is necessary to understand the nerves that support it. Nerve cells, or neurons, perform many functions in the body. Although their general purpose, providing an interface between the brain and the body, remains constant, their capabilities vary widely. Certain types of neurons are capable of transmitting a pain signal to the brain. As a group, these pain-sensing neurons are called nociceptors, and virtually every surface and organ of the body is wired with them. The central part of these cells is located in the spine, and they send threadlike projections to every part of the body. Nociceptors are classified according to the stimulus that prompts them to transmit a pain signal. Thermoreceptive nociceptors are stimulated by temperatures that are potentially tissue damaging. Mechanoreceptive nociceptors respond to a pressure stimulus that may cause injury. Polymodal nociceptors are the most sensitive and can respond to temperature and pressure. Polymodal nociceptors also respond to chemicals released by the cells in the area from which the pain originates. Nerve cell endings, or receptors, are at the front end of pain sensation. A stimulus at this part of the nociceptor unleashes a cascade of neurotransmitters (chemicals that transmit information within the nervous system) in the spine. Each neurotransmitter has a purpose. For example, substance P relays the pain message to nerves leading to the spinal cord and brain. These neurotransmitters may also stimulate nerves leading back to the site of the injury. This response prompts cells in the injured area to release chemicals that not only trigger an immune response, but also influence the intensity and duration of the pain. Chronic and abnormal pain Chronic pain refers to pain that persists after an injury heals, cancer pain, pain related to a persistent or degenerative disease, and long-term pain from an unidentifiable cause. It is estimated that one in three people in the United States will experience chronic pain at some point in their lives. Of these people, approximately 50 million are either partially or completely disabled. Chronic pain may be caused by the bodyx0027s response to acute pain. In the presence of continued stimulation of nociceptors, changes occur within the nervous system. Changes at the molecular level are dramatic and may include alterations in genetic transcription of neurotransmitters and receptors. These changes may also occur in the absence of an identifiable cause one of the frustrating aspects of chronic pain is that the stimulus may be unknown. For example, the stimulus cannot be identified in as many as 85 of individuals suffering lower back pain. Scientists have long recognized a relationship between depression and chronic pain. In 2004, a survey of California adults diagnosed with major depressive disorder revealed that more than one-half of them also suffered from chronic pain. Other types of abnormal pain include allodynia, hyperalgesia, and phantom limb pain. These types of pain often arise from some damage to the nervous system (neuropathic). Allodynia refers to a feeling of pain in response to a normally harmless stimulus. For example, some individuals who have suffered nerve damage as a result of viral infection experience unbearable pain from just the light weight of their clothing. Hyperalgesia is somewhat related to allodynia in that the response to a painful stimulus is extreme. In this case, a mild pain stimulus, such as a pin prick, causes a maximum pain response. Phantom limb pain occurs after a limb is amputated although an individual may be missing the limb, the nervous system continues to perceive pain originating from the area. Causes and symptoms Pain is the most common symptom of injury and disease, and descriptions can range in intensity from a mere ache to unbearable agony. Nociceptors have the ability to convey information to the brain that indicates the location, nature, and intensity of the pain. For example, stepping on a nail sends an information-packed message to the brain: the foot has experienced a puncture wound that hurts a lot. Pain perception also varies depending on the location of the pain. The kinds of stimuli that cause a pain response on the skin include pricking, cutting, crushing, burning, and freezing. These same stimuli would not generate much of a response in the intestine. Intestinal pain arises from stimuli such as swelling, inflammation, and distension. Pain is considered in view of other symptoms and individual experiences. An observable injury, such as a broken bone, may be a clear indicator of the type of pain a person is suffering. Determining the specific cause of internal pain is more difficult. Other symptoms, such as fever or nausea, help narrow down the possibilities. In some cases, such as lower back pain, a specific cause may not be identifiable. Diagnosis of the disease causing a specific pain is further complicated by the fact that pain can be referred to (felt at) a skin site that does not seem to be connected to the site of the painx0027s origin. For example, pain arising from fluid accumulating at the base of the lung may be referred to the shoulder. Since pain is a subjective experience, it may be very difficult to communicate its exact quality and intensity to other people. There are no diagnostic tests that can determine the quality or intensity of an individualx0027s pain. Therefore, a medical examination will include a lot of questions about where the pain is located, its intensity, and its nature. Questions are also directed at what kinds of things increase or relieve the pain, how long it has lasted, and whether there are any variations in it. An individual may be asked to use a pain scale to describe the pain. One such scale assigns a number to the pain intensity for example, 0 may indicate no pain, and 10 may indicate the worst pain the person has ever experienced. Scales are modified for infants and children to accommodate their level of comprehension. There are many drugs aimed at preventing or treating pain. Nonopioid analgesics. narcotic analgesics, anticonvulsant drugs, and tricyclic antidepressants work by blocking the production, release, or uptake of neurotransmitters. Drugs from different classes may be combined to handle certain types of pain. Nonopioid analgesics include common over-the-counter medications such as aspirin. acetaminophen (Tylenol), and ibuprofen (Advil). These are most often used for minor pain, but there are some prescription-strength medications in this class. Narcotic analgesics are only available with a doctorx0027s prescription and are used for more severe pain, such as cancer pain. These drugs include codeine, morphine, and methadone. Addiction to these painkillers is not as common as once thought. Many people who genuinely need these drugs for pain control typically do not become addicted. However, narcotic use should be limited to patients thought to have a short life span (such as people with terminal cancer) or patients whose pain is only expected to last for a short time (such as people recovering from surgery). In August 2004, the Drug Enforcement Administration (DEA) issued new guidelines to help physicians prescribe narcotics appropriately without fear of being arrested for prescribing the drugs beyond the scope of their medical practice. DEA is trying to work with physicians to ensure that those who need to drugs receive them but to ensure opioids are not abused. Anticonvulsants, as well as antidepressant drugs. were initially developed to treat seizures and depression, respectively. However, it was discovered that these drugs also have pain-killing applications. Furthermore, since in cases of chronic or extreme pain, it is not unusual for an individual to suffer some degree of depression antidepressants may serve a dual role. Commonly prescribed anticonvulsants for pain include phenytoin, carbamazepine, and clonazepam. Tricyclic antidepressants include doxepin, amitriptyline, and imipramine. Intractable (unrelenting) pain may be treated by injections directly into or near the nerve that is transmitting the pain signal. These root blocks may also be useful in determining the site of pain generation. As the underlying mechanisms of abnormal pain are uncovered, other pain medications are being developed. Drugs are not always effective in controlling pain. Surgical methods are used as a last resort if drugs and local anesthetics fail. The least destructive surgical procedure involves implanting a device that emits electrical signals. These signals disrupt the nerve and prevent it from transmitting the pain message. However, this method may not completely control pain and is not used frequently. Other surgical techniques involve destroying or severing the nerve, but the use of this technique is limited by side effects, including unpleasant numbness. Alternative treatment Both physical and psychological aspects of pain can be dealt with through alternative treatment. Some of the most popular treatment options include acupressure and acupuncture. massage, chiropractic, and relaxation techniques such as yoga. hypnosis, and meditation. Herbal therapies are gaining increased recognition as viable options for example, capsaicin, the component that makes cayenne peppers spicy, is used in ointments to relieve the joint pain associated with arthritis. Contrast hydrotherapy can also be very beneficial for pain relief. Lifestyles can be changed to incorporate a healthier diet and regular exercise. Regular exercise, aside from relieving stress. has been shown to increase endorphins, painkillers naturally produced in the body. Successful pain treatment is highly dependent on successful resolution of the painx0027s cause. Acute pain will stop when an injury heals or when an underlying problem is treated successfully. Chronic pain and abnormal pain are more difficult to treat, and it may take longer to find a successful resolution. Some pain is intractable and will require extreme measures for relief. Prevention Pain is generally preventable only to the degree that the cause of the pain is preventable. For example, improved surgical procedures, such as those done through a thin tube called a laparascope, minimize post-operative pain. Anesthesia techniques for surgeries also continuously improve. Some disease and injuries are often unavoidable. However, pain from some surgeries and other medical procedures and continuing pain are preventable through drug treatments and alternative therapies. Periodicals x0022Advances in Pain Management, New Focus Greatly Easing Postoperative Care. x0022 Medical Devices x0026 Surgical Technology Week September 26, 2004: 260. Finn, Robert. x0022More than Half of Patients With Major Depression Have Chronic Pain. x0022 Family Practice News October 15, 2004: 38. x0022New Guidelines Set for Better Pain Treatment. x0022 Medical Letter on the CDC x0026 FDA September 5, 2004: 95. Organizations American Chronic Pain Association. P. O. Box 850, Rocklin, CA 95677-0850. (916) 632-0922. x2329members. tripodx223CwiddyACPA. htmlx232A. American Pain Society. 4700 W. Lake Ave. Glenview, IL 60025. (847) 375-4715. ampainsoc. org . Acute pain mdash Pain in response to injury or another stimulus that resolves when the injury heals or the stimulus is removed. Chronic pain mdash Pain that lasts beyond the term of an injury or painful stimulus. Can also refer to cancer pain, pain from a chronic or degenerative disease, and pain from an unidentified cause. Neuron mdash A nerve cell. Neurotransmitters mdash Chemicals within the nervous system that transmit information from or between nerve cells. Nociceptor mdash A neuron that is capable of sensing pain. Referred pain mdash Pain felt at a site different from the location of the injured or diseased part of the body. Referred pain is due to the fact that nerve signals from several areas of the body may x0022feedx0022 the same nerve pathway leading to the spinal cord and brain. Stimulus mdash A factor capable of eliciting a response in a nerve. a feeling of distress, suffering, or agony, caused by stimulation of specialized nerve endings. Its purpose is chiefly protective it acts as a warning that tissues are being damaged and induces the sufferer to remove or withdraw from the source. The North American Nursing Diagnosis Association has accepted pain as a nursing diagnosis. defining it as a state in which an individual experiences and reports severe discomfort or an uncomfortable sensation the reporting of pain may be either by direct verbal communication or by encoded descriptors. Pain Receptors and Stimuli. All receptors for pain stimuli are free nerve endings of groups of myelinated or unmyelinated neural fibers abundantly distributed in the superficial layers of the skin and in certain deeper tissues such as the periosteum, surfaces of the joints, arterial walls, and the falx and tentorium of the cranial cavity. The distribution of pain receptors in the gastrointestinal mucosa apparently is similar to that in the skin thus, the mucosa is quite sensitive to irritation and other painful stimuli. Although the parenchyma of the liver and the alveoli of the lungs are almost entirely insensitive to pain, the liver and bile ducts are extremely sensitive, as are the bronchi and parietal pleura. Some pain receptors are selective in their response to stimuli, but most are sensitive to more than one of the following types of excitation: (1) mechanical stress of trauma (2) extremes of heat and cold and (3) chemical substances, such as histamine, potassium ions, acids, prostaglandins, bradykinin, and acetylcholine. Pain receptors, unlike other sensory receptors in the body, do not adapt or become less sensitive to repeated stimulation. Under certain conditions the receptors become more sensitive over a period of time. This accounts for the fact that as long as a traumatic stimulus persists the person will continue to be aware that damage to the tissues is occurring. The body is able to recognize tissue damage because when cells are destroyed they release the chemical substances previously mentioned. These substances can stimulate pain receptors or cause direct damage to the nerve endings themselves. A lack of oxygen supply to the tissues can also produce pain by causing the release of chemicals from ischemic tissue. Muscle spasm is another cause of pain, probably because it has the indirect effect of causing ischemia and stimulation of chemosensitive pain receptors. Transmission and Recognition of Pain. When superficial pain receptors are excited the impulses are transmitted from these surface receptors to synapses in the gray matter ( substantia gelatinosa ) of the dorsal horns of the spinal cord. They then travel upward along the sensory pathways to the thalamus, which is the main sensory relay station of the brain. The dorsomedial nucleus of the thalamus projects to the prefrontal cortex of the brain. The conscious perception of pain probably takes place in the thalamus and lower centers interpretation of the quality of pain is probably the role of the cerebral cortex. The perception of pain by an individual is highly complex and individualized, and is subject to a variety of external and internal influences. The cerebral cortex is concerned with the appreciation of pain and its quality, location, type, and intensity thus, an intact sensory cortex is essential to the perception of pain. In addition to neural influences that transmit and modulate sensory input, the perception of pain is affected by psychological and cultural responses to pain-related stimuli. A person can be unaware of pain at the time of an acute injury or other very stressful situation, when in a state of depression, or when experiencing an emotional crisis. Cultural influences also precondition the perception of and response to painful stimuli. The reaction to similar circumstances can range from complete stoicism to histrionic behavior. Pain Control. There are several theories related to the physiologic control of pain but none has been completely verified. One of the best known is that of Mellzak and Wall, the gate control theory, which proposed that pain impulses were mediated in the substantia gelatinosa of the spinal cord with the dorsal horns acting as ldquogatesrdquo that controlled entry of pain signals into the central pain pathways. Also, pain signals would compete with tactile signals with the two constantly balanced against each other. Since this theory was first proposed, researchers have shown that the neuronal circuitry it hypothesizes is not precisely correct. Nevertheless, there are internal systems that are now known to occur naturally in the body for controlling and mediating pain. One such system, the opioid system, involves the production of morphinelike substances called enkephalins and endorphins. Both are naturally occurring analgesics found in various parts of the brain and spinal cord that are concerned with pain perception and the transmission of pain signals. Signals arising from stimulation of neurons in the gray matter of the brain stem travel downward to the dorsal horns of the spinal cord where incoming pain impulses from the periphery terminate. The descending signals block or significantly reduce the transmission of pain signals upward along the spinal cord to the brain where pain is perceived by releasing these substances. In addition to the brains opioid system for controlling the transmission of pain impulses along the spinal cord, there is another mechanism for the control of pain. The stimulation of large sensory fibers extending from the tactile receptors in the skin can suppress the transmission of pain signals from thinner nerve fibers. It is as if the nerve pathways to the brain can accommodate only one type of signal at a time, and when two kinds of impulses simultaneously arrive at the dorsal horns, the tactile sensation takes precedence over the sensation of pain. The discovery of endorphins and the inhibition of pain transmission by tactile signals has provided a scientific explanation for the effectiveness of such techniques as relaxation, massage, application of liniments, and acupuncture in the control of pain and discomfort. Assessment of Pain. Pain is a subjective phenomenon that is present when the person who is experiencing it says it is. The person reporting personal discomfort or pain is the most reliable source of information about its location, quality, intensity, onset, precipitating or aggravating factors, and measures that bring relief. Objective signs of pain can help verify what a patient says about pain, but such data are not used to prove or disprove whether it is present. Physiologic signs of moderate and superficial pain are responses of the sympathetic nervous system. They include rapid, shallow, or guarded respiratory movements, pallor, diaphoresis, increased pulse rate, elevated blood pressure, dilated pupils, and tenseness of the skeletal muscles. Pain that is severe or located deep in body cavities acts as a stimulant to parasympathetic neurons and is evidenced by a drop in blood pressure, slowing of pulse, pallor, nausea and vomiting, weakness, and sometimes a loss of consciousness. Behavioral signs of pain include crying, moaning, tossing about in bed, pacing the floor, lying quietly but tensely in one position, drawing the knees upward toward the abdomen, rubbing the painful part, and a pinched facial expression or grimacing. The person in pain also may have difficulty concentrating and remembering and may be totally self-centered and preoccupied with the pain. Psychosocial aspects of tolerance for pain and reactions to it are less easily identifiable and more complex than physiologic responses. An individuals reaction to pain is subject to a variety of psychologic and cultural influences. These include previous experience with pain, training in regard to how one should respond to pain and discomfort, state of health, and the presence of fatigue or physical weakness. Ones degree of attention to and distraction from painful stimuli can also affect ones perception of the intensity of pain. A thorough assessment of pain takes into consideration all of these psychosocial factors. Management of Pain. Among the measures employed to provide relief from pain, administration of analgesic drugs is probably the one that is most often misunderstood and abused. When an analgesic drug has been ordered ldquoas needed, rdquo the patient should know that the drug is truly available when needed and that it will be given promptly when asked for. If the patient is forced to wait until someone else decides when an analgesic is needed, the patient may become angry, resentful, and tense, thus diminishing or completely negating the desired effect of the drug. Studies have shown that when analgesics are left at the bedside of terminally ill cancer patients to be taken at their discretion, fewer doses are taken than when they must rely on someone else to make the drug available. Habituation and addiction to analgesics probably result as much from not using other measures along with analgesics for pain control as from giving prescribed analgesics when they are ordered. Patient-controlled analgesia has been used safely and effectively. When analgesics are not appropriate or sufficient or when there is a real danger of addiction, there are noninvasive techniques that can be used as alternatives or adjuncts to analgesic therapy. The selection of a particular technique for the management of pain depends on the cause of the pain, its intensity and duration, whether it is acute or chronic, and whether the patient perceives the technique as effective. Distraction techniques provide a kind of sensory shielding to make the person less aware of discomfort. Distraction can be effective in the relief of brief periods of acute pain, such as that associated with minor surgical procedures under local anesthesia, wound deacutebridement, and venipuncture. Massage and gentle pressure activate the thick-fiber impulses and produce a preponderance of tactile signals to compete with pain signals. It is interesting that stimulation of the large sensory fibers leading from superficial sensory receptors in the skin can relieve pain at a site distant from the area being rubbed or otherwise stimulated. Since ischemia and muscle spasm can both produce discomfort, massage to improve circulation and frequent repositioning of the body and limbs to avoid circulatory stasis and promote muscle relaxation can be effective in the prevention and management of pain. Transcutaneous electrical nerve stimulation (TENS) units enhance the production of endorphins and enkephalins and can also relieve pain. Specific relaxation techniques can help relieve physical and mental tension and stress and reduce pain. They have been especially effective in mitigating discomfort during labor and delivery but can be used in a variety of situations. Learning proper relaxation techniques is not easy for some people, but once these techniques have been mastered they can be of great benefit in the management of chronic ongoing pain. The intensity of pain also can be reduced by stimulating the skin through applications of either heat or cold, menthol ointments, and liniments. Contralateral stimulation involves stimulating the skin in an area on the side opposite a painful region. Stimulation can be done by rubbing, massaging, or applying heat or cold. Since pain is a symptom and therefore of value in diagnosis, it is important to keep accurate records of the observations of the patient having pain. These observations should include the following: the nature of the pain, that is, whether it is described by the patient as being sharp, dull, burning, aching, etc. the location of the pain, if the patient is able to determine this the time of onset and the duration, and whether or not certain nursing measures and drugs are successful in obtaining relief and the relation to other circumstances, such as the position of the patient, occurrence before or after eating, and stimuli in the environment such as heat or cold that may trigger the onset of pain. Surgical procedures designed to alleviate pain. From Ignatavicius et al. 1999. 1. one of the three categories of pain established by the International Association for the Study of Pain, denoting pain that is caused by occurrences such as traumatic injury, surgical procedures, or medical disorders clinical symptoms often include increased heart rate, blood pressure, and respiratory rate, shallow respiration, agitation or restlessness, facial grimaces, or splinting. 2. a nursing diagnosis accepted by the North American Nursing Diagnosis Association, defined as an unpleasant sensory and emotional experience arising from actual or potential tissue damage or described in terms of such damage, with sudden or slow onset of any intensity from mild to severe with an anticipated or predictable end and a duration of less than 6 months. bearing-down pain pain accompanying uterine contractions during the second stage of labor . cancer pain one of the three categories of pain established by the International Association for the Study of Pain, denoting pain associated with malignancies and perceived by the individual patient there are various scales ranking it from 0 to 10 according to level of severity. 1. one of the three categories of pain established by the International Association for the Study of Pain, denoting pain that is persistent, often lasting more than six months clinical symptoms may be the same as for acute pain, or there may be no symptoms evident. The North American Nursing Diagnosis Association has accepted chronic pain as a nursing diagnosis . 2. a nursing diagnosis accepted by the North American Nursing Diagnosis Association, defined as an unpleasant sensory and emotional experience arising from actual or potential tissue damage or described in terms of such damage, with sudden or slow onset of any intensity from mild to severe, without an anticipated or predictable end, and with a duration of greater than 6 months. pain disorder a somatoform disorder characterized by a chief complaint of severe chronic pain that causes substantial distress or impairment in functioning the pain is neither feigned nor intentionally produced, and psychological factors appear to play a major role in its onset, severity, exacerbation, or maintenance. The pain is related to psychological conflicts and is made worse by environmental stress it enables the patient to avoid an unpleasant activity or to obtain support and sympathy. Patients may visit many health care providers searching for relief and may consume excessive amounts of analgesics without any effect. They are difficult to treat because they strongly resist the idea that their symptoms have a psychological origin. false ps ineffective pains during pregnancy that resemble labor pains, not accompanied by cervical dilatation see also braxton-hicks contractions. Called also false labor . growing ps any of various types of recurrent limb pains resembling those of rheumatoid conditions, seen in early youth and formerly thought to be caused by the growing process. hunger pain pain coming on at the time for feeling hunger for a meal a symptom of gastric disorder. intermenstrual pain pain accompanying ovulation, occurring during the period between the menses, usually about midway. labor ps the rhythmic pains of increasing severity and frequency due to contraction of the uterus at childbirth see also labor . lancinating pain sharp darting pain. phantom pain pain felt as if it were arising in an absent or amputated limb or organ see also amputation . psychogenic pain symptoms of physical pain having psychological origin see pain disorder . referred pain pain in a part other than that in which the cause that produced it is situated. Referred pain usually originates in one of the visceral organs but is felt in the skin or sometimes in another area deep inside the body. Referred pain probably occurs because pain signals from the viscera travel along the same neural pathways used by pain signals from the skin. The person perceives the pain but interprets it as having originated in the skin rather than in a deep-seated visceral organ. Area of referred pain, anterior and posterior views. rest pain a continuous unrelenting pain due to ischemia of the lower leg, beginning with or being aggravated by elevation and being relieved by sitting with legs in a dependent position or by standing. root pain pain caused by disease of the sensory nerve roots and occurring in the cutaneous areas supplied by the affected roots. 1. A variably unpleasant sensation associated with actual or potential tissue damage and mediated by specific nerve fibers to the brain where its conscious appreciation may be modified by various factors. 2. Term used to denote a painful uterine contraction occurring in childbirth. L. poena, a fine, a penalty ( px0101n ) a feeling of distress, suffering, or agony, caused by stimulation of specialized nerve endings. bearing-down pain pain accompanying uterine contractions during the second stage of labor. false pains ineffective pains resembling labor pains, not accompanied by cervical dilatation. growing pains recurrent quasirheumatic limb pains peculiar to early youth. hunger pain pain coming on at the time for feeling hunger for a meal a symptom of gastric disorder. intermenstrual pain pain accompanying ovulation, occurring during the period between the menses, usually about midway. labor pains the rhythmic pains of increasing severity and frequency due to contraction of the uterus at childbirth. phantom limb pain pain felt as though arising in an absent (amputated) limb. psychogenic pain symptoms of physical pain having psychological origin. referred pain pain felt in a part other than that in which the cause that produced it is situated. rest pain a continuous burning pain due to ischemia of the lower leg, which begins or is aggravated after reclining and is relieved by sitting or standing. 1. An unpleasant feeling occurring as a result of injury or disease, usually localized in some part of the body. 2. Mental or emotional suffering distress. 3. One of the uterine contractions occurring in childbirth. Etymology: L, poena, punishment an unpleasant sensation caused by noxious stimulation of the sensory nerve endings. It is a subjective feeling and an individual response to the cause. Pain is a cardinal symptom of inflammation and is valuable in the diagnosis of many disorders and conditions. It may be mild or severe, chronic or acute, lancinating, burning, dull or sharp, precisely or poorly localized, or referred. Experiencing pain is influenced by physical, mental, biochemical, psychological, physiological, social, cultural, and emotional factors. See also acute pain, chronic pain, referred pain. Neurology An unpleasant sensory and emotional experience associated with actual or potential tissue damage or described in terms of such damage-per Intl Assn for Study of Pain a sensation of discomfort, distress, or agony, due to stimulation of specialized nerve endings a sensation of marked discomfort, either sharp and well-localizedndashconducted along A-delta fibers or dull and diffusendashconducted along C nerve fibers. See Acute pain. Acute low back pain. Ankle pain, Back pain. Breakthrough pain. Brief Pain Inventory. Central stroke pain, Chest pain. Chest wall pain. Chronic pain, Discogenic pain. Elbow pain, Gait control theory, Growing pain, Intractable pain. Knee pain, Lightning pain, Low back pain. Noncardiac chest pain, Patient controlled analgesia, Phantom limb pain, Substantial pain. Suprapubic pain. An unpleasant sensation associated with actual or potential tissue damage, and mediated by specific nerve fibers to the brain, where its conscious appreciation may be modified by various factors. L. poena, a fine, a penalty (pan) Fr. peine . fr L. poena . a fine, a penalty, punishment As defined by the International Association for the Study of Pain, an unpleasant sensory and emotional experience arising from actual or potential tissue damage or described in terms of such damage. Pain includes not only the perception of an uncomfortable stimulus but also the response to that perception. About half of those who seek medical help do so because of the primary complaint of pain. Acute pain occurs with an injury or illness is often accompanied by anxiety, diaphoresis, nausea, and vital sign changes such as tachycardia or hypertension and should end after the noxious stimulus is removed or any organ damage heals. Chronic or persistent pain is discomfort that lasts beyond the normal healing period. Pain may arise in nearly any organ system and may have different characteristics in each. Musculoskeletal pain often is exacerbated by movement and may be accompanied by joint swelling or muscle spasm. Myofascial pain is marked by trigger-point tenderness. Visceral pain often is diffuse or vaguely localized, whereas pain from the lining of body cavities often is localized precisely, very intense, and exquisitely sensitive to palpation or movement. Neuropathic (nerve) pain usually stings or burns, or may be described as numbness, tingling, or shooting sensations. Colicky pain fluctuates in intensity from severe to mild, and usually occurs in waves. Referred pain results when an injury or disease occurs in one body part but is felt in another. Several factors influence the experience of pain. Among these are the nature of the injury or illness causing the symptom, the physical and emotional health of the patient, the acuity or chronicity of the symptom, the social milieu andor cultural upbringing of the patient, neurochemistry, memory, personality, and other features. See: table Many clinicians use the mnemonic COLDER to aid the diagnosis of painful diseases. They will ask the patient to describe the C haracter, O nset, L ocation, and D uration of their painful symptoms, as well as the features that E xacerbate or R elieve it. For example: The pain of pleurisy typically is sharp in character, acute in onset, located along the chest wall, and long-lasting it is worsened by deep breathing or coughing and relieved by analgesics or holding still. By contrast, the pain of myocardial ischemia usually is dull or heavy, gradual in onset, and located substernally. It may be worsened by activity (but not by taking a breath or coughing) and relieved by nitroglycerin. In 2000, the Joint Commission on Accreditation of Healthcare Organizations (JCAHO) issued pain-management standards, in 2001 began surveying for compliance, and in 2004 added patient-safety goals, thus most U. S. health care facilities have devised policies and procedures that require pain-intensity rating as a routine part of care (the fifth vital sign). Pain intensity usually is assessed on a numerical scale, in which 0 no pain, 1 to 3 mild pain, 4 to 6 moderate pain, and 7 to 10 severe pain. However, obtaining a numerical rating of pain intensity is possible only if the patient is able to provide this report of the pain being experienced, which infants, children, the critically ill, and cognitively impaired usually are unable to do. The Wong Baker FACES scale, developed for pediatric use, has been used successfully in other patient populations. It uses visual representations of smiles or grimaces to depict the level of pain a patient feels. Patient care Health care professionals must be aware that pain in non-verbal patient can easily be overlooked and must make a conscious effort to ensure that pain in these patients is assessed and treated. Observing subtle behaviors and being sensitive to contextual clues are two pain methods used by health care professionals to try to determine when nonverbal patients are in pain. When this judgment is made, a trial of pain-relieving medication may be used. The responses of the patient and any complications of treatment should be carefully observed and appropriate changes made in dosing or the type of analgesic drug as indicated. Because pain is a subjective and intensely personal problem, sympathetic care is an important part of its relief. In addition to administering analgesic drugs, health care professionals should use a wide range of techniques to help alleviate pain, including local application of cold and heat, tactile stimulation, relaxation techniques, diversion, and active listening, among others. acute pain Pain that typically is produced by sudden injury (e. g. fracture) or illness (e. g. acute infection) and is accompanied by physical signs such as increased heart rate, elevated blood pressure, pupillary dilation, sweating, or hyperventilation. Acute pain is typically sharp in character. It is relayed to the central nervous system rapidly by A delta nerve fibers. Then, at the end of this entry please add the SYN: fast pain Depending on the severity of the underlying stimulus, acute pain may be managed with acetaminophen or anti-inflammatory drugs, immobilization and elevation of the injured body part, or the topical application of heat or ice. Severe acute pain, such as that of broken ribs or of an ischemic part, may require narcotics, often with adjunctive agents like hydroxyzine for relief, or antiemetics. Acute pain should be managed aggressively. Synonym: fast pain adnexal pain Discomfort arising from the fallopian tubes and ovaries usually due to inflammation, infection, or ectopic pregnancy. Pain felt in or along the spine or musculature of the posterior thorax. It is usually characterized by dull, continuous pain and tenderness in the muscles or their attachments in the lower lumbar, lumbosacral, or sacroiliac regions. Back pain is often referred to the leg or legs, following the distribution of the sciatic nerve. Common causes of back pain include pain caused by muscular or tendon strain, herniated intervertebral disk, lumbar spinal stenosis, or spondylolisthesis. Patients with a history of cancer may have back pain caused by metastatic tumors to the vertebrae and should be evaluated to be certain that damage to the spinal cord is not imminent. Patients with back pain and fever (esp. those with a history of injection drug use, tuberculosis, or recent back surgery) should be evaluated for epidural abscess or osteomyelitis. Depending on the underlying cause of the back pain, treatment may include drugs, rest, massage, physical therapy, chiropractic, stretching exercises, injection therapy, and surgery, among others. Most nonmalignant causes of back pain improve with a few days of rest, analgesics, and antiinflammatory drugs, followed by 2 to 4 weeks of anti-inflammatory treatment, appropriate muscle strengthening, and patience. Pain caused by an osteoporotic fracture may prove more debilitating and longer-lasting. Back pain produced by a spinal metastasis can improve with corticosteroids, radiation therapy, intravenous bisphosphonates, andor surgical decompression. Patients with a spinal epidural abscess will need surgical drainage of the infection and antibiotics. Patient care Prolonged bedrest is inadvisable in most patients with back pain. The treatment regimen is explained, implemented, and reinforced. Factors that precipitate symptoms are identified and preventive actions are discussed. bearing-down pains Rectal pressure and discomfort occurring during the second stage of labor, related to fetal descent and the womans straining efforts to expel the fetus. boring pain Piercing, used to describe pain felt deep within the body. breakthrough pain Transient episodes of pain that occur in patients with chronic pain that has been previously reduced to tolerable levels. Breakthrough pain disrupts the well-being of cancer or hospice patients who have been prescribed regular doses of narcotic analgesics. The painful episodes may occur as a previous dose of pain-relieving medication wears off (end-of-dose pain), or after unusual or unanticipated body movements (incident pain). Brodie pain Pain caused near a joint affected with neuralgia when the skin is folded near it. burning pain Pain experienced in heat burns, superficial skin lesions, herpes zoster, and circumscribed neuralgias. causalgic pain central pain Pain due to a lesion in the central nervous system. chest pain Discomfort felt in the upper abdomen, thorax, neck, or shoulders. Chest pain is one of the most common potentially serious complaints offered by patients in emergency departments, hospitals, outpatient settings, and physicians offices. A broad array of diseases and conditions may cause it, including (but not limited to) angina pectoris or myocardial infarction anxiety and hyperventilation aortic dissection costochondritis or injured ribs cough, pneumonia, pleurisy, pneumothorax, or pulmonary emboli esophageal diseases, such as reflux or esophagitis gastritis, duodenitis, or peptic ulcer and stones in the biliary tree. chronic idiopathic pelvic pain Unexplained pelvic pain in a woman that has lasted 6 months or longer. A complete medical, social, and sexual history must be obtained. In an experimental study, women with this illness reported more sexual partners, significantly more spontaneous abortions, and previous nongynecological surgery. These women were more likely to have experienced previous significant psychosexual trauma. The pain associated with CIPP should be treated symptomatically and sympathetically. The participation of pain management specialists, complementary medical providers, and the primary health care provider should be integrated. Realistic goals (e. g. the reduction of pain rather than its elimination) should be set. Medroxyprogesterone acetate, oral contraceptives, presacral neurectomy, hypnosis, and hysterectomy have been tried with varying degrees of success. chronic pain 1. Long-lasting discomfort, with episodic exacerbations, that may be felt in the back, one or more joints, the pelvis, or other parts of the body. 2. Pain that lasts more than 36 months. 3. Pain that lasts more than a month longer than the usual or expected course of an illness. 4. Pain that returns periodically every few weeks or months for many years. Chronic pain is often described by sufferers as being debilitating, intolerable, disabling, or alienating and may occur without an easily identifiable cause. Studies have shown a high correlation between chronic pain and depression or dysphoria, but it is unclear whether the psychological aspects of chronic pain precede or develop as a result of a persons subjective suffering. Chronic pain is the leading cause of disability in the U. S.acute pain Patient care The management of chronic, nonmalignant pain is often difficult and may be frustrating for both sufferer and caregiver. The best results are usually obtained through multimodal therapy that combines sympathetic guidance that encourages patients to recover functional abilities, by combinations of drugs (e. g. nonsteroidal anti-inflammatories, narcotic analgesics, andor antidepressants), physical therapy and regular exercise, occupational therapy, physiatry, psychological or social counseling, and alternative medical therapies (e. g. acupuncture, massage, or relaxation techniques). Placebos, although rarely employed clinically, effectively treat chronic pain in about a third of all patients. Surgery and other invasive strategies are occasionally employed, with variable effectiveness. cramplike pain dental pain Pain in the oral area, which, in general, may be of two origins. Soft tissue pain may be acute or chronic, and a burning pain is due to surface lesions and usually can be discretely localized pulpal pain or tooth pain varies according to whether it is acute or chronic, but it is often difficult to localize. dilating pain Discomfort accompanying rhythmic uterine contractions during the first stage of labor. diskogenic pain Low back pain resulting from degeneration of an intervertebral disk. Discogenic pain differs from neuropathic pain in that it does not radiate into the extremities or torso. A mild discomfort, often difficult to describe, that may be associated with some musculoskeletal injuries or some diseases of the visceral organs. eccentric pain Pain occurring in peripheral structures owing to a lesion involving the posterior roots of the spinal nerves. epigastric pain Pain located between the xiphoid process and the umbilicus. It may suggest a problem in one of many different organs, including the stomach, pancreas, gallbladder, small or large bowel, pleura, or heart. expulsive pains Discomfort during the second stage of labor, associated with bearing-down efforts to expel the fetus. Women may experience a similar pain during delivery of the placenta. false pain Abdominal discomfort associated with Braxton Hicks contractions, which occur during the last trimester of pregnancy. Characteristically, the woman complains of irregular, lower abdominal pains, which are relieved by walking. Vaginal examination shows no change in cervical effacement or dilation. fulgurant pain gallbladder pain Pain in the intestines caused by an accumulation of gas therein. gastralgic pain girdle pain growing pains An imprecise term indicating ill-defined pain, usually in the shin or other areas of the legs, typically occurring after bedtime in children age 5 to 12. There is no evidence that the pain is related to rapid growth or to emotional problems. If these symptoms occur during the daytime, are accompanied by other symptoms, or become progressively more severe, evaluation for infection, cancer, and other diseases of muscle and bone should be undertaken. In the majority of cases, this evaluation is not necessary. The child should be reassured and given acetaminophen or ibuprofen heat and massage can be applied locally. Children with growing pains benefit from concern and reassurance from their parents and health care providers. heterotopic pain homotopic pain Pain felt at the point of injury. hunger pain Pain in the epigastrum that occurs before meals. incident pain Pain due to a sudden, forceful, unanticipated, or unusual body movement or posture. inflammatory pain Pain in the presence of inflammation that is increased by pressure. intermenstrual pain Episodic, localized pelvic discomfort that occurs between menstrual periods, possibly accompanying ovulation. intractable pain Chronic pain that is difficult or impossible to manage with standard interventions. Common causes include metastatic cancer, chronic pancreatitis, radiculopathy, spinal cord transection, or peripheral neuropathy. Intractable pain may also accompany somatoform disorders, depression, fibromyalgia, irritable bowel syndrome, and opiate dependence. Various combinations of the following management strategies are often used to treat intractable pain: antidepressant medications, counseling, deep brain stimulation, injected anesthetics, narcotic analgesics, neurological surgery, and pain clinic consultations. labor pains Uncomfortable, intermittent, rhythmic, girdling sensations associated with uterine contractions during childbearing. The frequency, duration, and intensity of the events increase, climaxing with the delivery of the fetus. lancinating pain lightning pain A sudden brief pain that may be repetitive, usually in the legs but may be at any location. It is associated with tabes dorsalis and other neurological disorders. Synonym: fulgurant pain lingual pain Pain in the tongue that may be due to local lesions, glossitis, fissures, or pernicious anemia. Synonym: tongue pain Sharp pain in the region of the lungs. menstrual pain mental pain Periumbilical and R lower abdomen NOTE: L left R right. An unpleasant or distressing localized sensation caused by stimulation of certain sensory nerve endings called nociceptors, or by strong stimulation of other sensory nerves. Nociceptors are stimulated by the chemical action of substances, such as prostaglandins, released from local cell damaged by injury or inflammation. Whatever the site of nerve stimulation, pain is usually experienced in the region of the nerve endings. Referred pain is pain experienced at a site other than that at which the causal factor is operating. Pain impulses pass to the brain via a series of control x2018gatesx2019 analogous to those in computers and these can be modulated by other nerve impulses. Pain commonly serves as a warning of bodily danger and leads to action to end it. Pain is best treated by discovering and removing the cause. It is a complex phenomenon with many components-somatic, emotional, cognitive and social. The management of acute, self-limiting pain is not the same as long-term pain. The latter requires treatment by a multidisciplinary team in a pain clinic. ANALGESIC drugs can be used to target specific receptors and should not be withheld until pain is severe but given repeatedly in expectation of pain. Pain may be relieved by drugs self-administered on an as-required basis by electrical stimulation of the skin ACUPUNCTURE massage cold sprays LOCAL ANAESTHETIC injections or even, in extreme cases and rarely, by permanent nerve destruction by alcohol injection or by surgical severance. From the Latin poena, punishment. See also ENDORPHINS. an unpleasant, conscious sensation produced in the brain and stimulated by pain receptors in, for example, the skin. Pain has a protective function and often produces a reflex action (see REFLEX ARC in response. the name that we give to the unpleasant and disturbing subjective experience that results from injury or other damage. Sensory receptors involved are known as nociceptors (from the adj noxious meaning harmful) thence afferent nerve impulses reach the central nervous system (CNS), where different influences can diminish or enhance them, acting where they are relayed and transmitted to the cerebral cortex and conscious perception. The pain pathways are separate from those serving other sensations, and even vigorous stimulation of other sensory receptors does not, by itself, cause pain. pain management involves a multdisciplinary approach, often by a specialist team. See also endorphins. transcutaneous electromagnetic nerve stimulation (TENS) . unpleasant sensory and emotional experience associated with, or described in terms of, actual or potential tissue damage, due to a complex interaction of sensory, emotional and behavioural factors pain may be acute or chronic, somatic, visceral or neurogenic it characterizes inflammation phantom-limb pain subjective pain or paraesthesia experienced within an amputated limb referred pain pain perceived as originating from a specific body area although it is remote from the point of pain origin, e. g. heel pain due to S1 nerve lesion n unpleasant emotional or physical sensation, often associated with potential or actual tissue damage and classified as acute, chronic, or cancer-related. See also cancer-related pain . Variably unpleasant sensation associated with tissue damage and mediated by specific nerve fibers to brain where its conscious appreciation is modified. L. poena, a fine, a penalty n an unpleasant sensation created by a noxious stimulus mediated along specific nerve pathways to the central nervous system, where it is interpreted. The sensation of pain is a protective mechanism that warns of danger without giving too much information about the specific nature of the danger. It initiates nociceptive reflexes. pain and suffering , n an element in a claim for damages in a liability lawsuit. It requests compensation to an individual for mental and physical pain and discomfort as a result of an injury. n an evaluation of the reported pain and the factors that alleviate or exacerbate a patients pain used as an aid in the diagnosis and the treatment of disease and trauma. n pain that occurs in the chest region because of disorders of the heart (e. g. angina pectoris, myocardial infarction, or pericarditis), pulmonary artery (pulmonary embolism or hypertension), lungs (pleuritis), esophagus (x201Cheartburnx201D), abdominal organs (aerophagia, biliary tract disease, splenic infarction, or gaseous distention in the splenic flexure), or the chest wall (neoplasia, costochondral strains, trauma, hyperventilation, or muscular tension). n a multidisciplinary association of health care professionals devoted to the diagnosis and treatment of patients with acute and chronic pain. n dull, aching, or boring pain originating in muscles, tendons, and joints. It is poorly localized and tends to radiate. pain dysfunction syndrome , n in dentistry, a phrase used to describe a condition in patients who appear to have a psychophysiologic basis for stress overload on the temporomandibular joint. The preferred term is mandibular stress syndrome . n the network that communicates unpleasant sensations and the perceptions of noxious stimuli throughout the body in association with both physical disease and trauma involving tissue damage. pain, nerve ending , n a receptor nerve ending that is relatively primitive and ends in an undifferentiated arborization. The nerve ending for the sensation of pain is a protective mechanism that warns of danger without giving too much information about the specific nature of the danger. The danger stimuli give rise to nociceptive reflexes, or defensive, protective, or withdrawal movements. The nociceptive reflexes supersede other, less urgent, reflexes that are thus inhibited. pain, projected pathologic , n pain erroneously perceived to arise in a peripheral region because of a stimulus from end-organs supplying the region (e. g. sciatic pain). Actually the stimulus occurred somewhere along the pain pathway from the nerve to the cortex. n the individuals manifestation of the unpleasant sensation. n pain caused by an agent in one area but manifested in another (e. g. pain caused by caries in the maxillary third molar may be referred to the mandible, so the source of pain appears to be in the mandible). n an agent that has the potential to induce pain, whether through chemical, mechanical, or thermal means. pain, tactile stimuli , n any of a number of physical sources that may aggravate dentin hypersensitivity, such as dental instruments, toothbrush bristles, ill-fitting oral prostheses, and various personal oral habits a patient may have. pain, thermal stimuli , n dentin hypersensitivity related to abrupt changes in temperature of teeth as a result of contact with very cold or very hot foods and liquids, rapid intake of air through the oral cavity, and during professional oral hygiene procedures requiring rapid drying of teeth. n the point at which a stimulus causes pain. It varies widely among individuals. n the maximum pain level an individual is able to withstand. a feeling of distress, suffering or agony, caused by stimulation of specialized nerve endings. Its purpose is chiefly protective it acts as a warning that tissues are being damaged and induces the sufferer to remove or withdraw from the source. All receptors for pain stimuli are free nerve endings of groups of myelinated or unmyelinated neural fibers abundantly distributed in the superficial layers of the skin and in certain deeper tissues such as the periosteum, surfaces of the joints, arterial walls, and the falx and tentorium of the cranial cavity. The distribution of pain receptors in the gastrointestinal mucosa apparently is similar to that in the skin thus, the mucosa is quite sensitive to irritation and other painful stimuli. Although the parenchyma of the liver and the alveoli of the lungs are almost entirely insensitive to pain, the liver as an organ and the bile ducts are extremely sensitive, as are the bronchi, ureters, parietal pleura and peritoneum. Some pain receptors are selective in their response to stimuli, but most are sensitive to more than one of the following types of excitation: (1) mechanical stress of trauma (2) extremes of heat and cold and (3) chemical substances, such as histamine, potassium ions, acids, prostaglandins, bradykinin and acetylcholine. The conscious perception of pain probably takes place in the thalamus and lower centers interpretation of the quality of pain is probably the role of the cerebral cortex. There are some naturally occurring internal systems in the body that are known to control pain but none of them has been completely verified. One of the best known is the gate control system in which it is thought that pain impulses are mediated in the substantia gelatinosa of the spinal cord. pain occurring in the area between the thorax and pelvis. Manifestations vary between species. Identifiable syndromes include: (1) horsex2014pawing, flank watching, rolling, straddling as though to urinate, lying on the back (2) cattlex2014may depress back and paddle with hindfeet but mostly arched back, grunting, immobility (3) dogs and catsx2014arched back, grunting, depression, reluctance to move. Sometimes there is elevation of the hindquarters, with the chest and forelegs on the ground (the so-called praying dog attitude). Beagle pain syndrome see beagle pain syndrome. pathology in one area can affect the nerve supply to a distant area in which pain is experienced. free nerve endings of tufts of fine points or buttons. pain felt in an area distant from the site of pathology but not mediated through a common innervation. There is no evidence that referred pain occurs in animals but it seems likely on anatomical grounds. the lowest level at which a stimulus can be applied and cause perceptible pain. the level of stimulation at which pain becomes intolerable. Patient discussion about pain Q. Pulling pain in anus. Dear friends, I am 32. I feel a Pulling pain in anus sometimes while i finish passing stool and some times when i sit for long time. No bleeding so far. Is it a symptoms of piles If so what can be done to cure it without going to doctor or operation. Please help me. This pain makes me to feel that i am very old. A. horsechestnut is supposed to help. here is some info about it: nccam. nih. govhealthhorsechestnutindex. htmuses but i wouldnt get my hopes high. Q. Polio Syndrome pain One of my aunt is taking Neurontin for Post Polio Syndrome pain in her left leg and arm. she did not realize that she had so much pain and that it was keeping her from doing so many things. Is Neurontin recomended for this treatment and how does it help Will she have problems with Neurontin if she take it long term Neurontin is greatly helping the pain but not the fatique in these limbs. Should it help the fatigue A. Neurontin is being given as medication for nerve pain now also. I take 800 mg a day and it was started for back pain and it is also being used in some fibro patients I am learning( i also have fibromyalgia) It didnt cause me a lot of drowsness but amount of medication and medications affect people differently so each person can be different. But with the fatigue fibromyalgia causes maybe I just cant tell the difference bc before I started it I was tried all the time and that is not any worse. But if your Aunt and yourself feel uncomfortable with this treatment I would suggest a second opinion. Good Luck to your Aunt Q. Why do they think that the pain is all in my head Is there any chance which may wrongfully lead doctor to conclude that our symptoms are of a psychological nature Why do they think that the pain is all in my head A. It may happen very rarely and if he is new to his profession. It doesnt mean that all those are new to their profession does these mistakes. Doctors cannot quotseequot and may not understand the sources of your pain or fatigue. However, what they do observe is your anxiety and frustration with having to deal with these symptoms around-the-clock, which may wrongfully lead them to conclude that your symptoms are of a psychological nature. Also, the old school of thought regarding pain is that it is produced by tissue injury, and there is no obvious source of tissue injury in patients with fibromyalgia. Regardless, if your doctor does not believe that your symptoms are real, you owe it to yourself to find another doctor who believes in you and will work with you to help reduce your symptoms. Link to this page: As when ALCIDES from OEALIA Crownd With conquest, felt th envenomd robe, and tore Through pain up by the roots THESSALIAN Pines, And LICHAS from the top of OETA threw Into th EUBOIC Sea. The little blistering voices of pain that had called out from his scalp were, he thought, definite in their expression of danger. It was necessary that pain should be put forward as a mode of self - realisation. After growing confused from pain while being carried into the hut he again regained consciousness, and while drinking tea once more recalled all that had happened to him, and above all vividly remembered the moment at the ambulance station when, at the sight of the sufferings of a man he disliked, those new thoughts had come to him which promised him happiness. If you have never swallowed it, the pill can not have given you a pain . After all her pains her heroic struggle for freedom had failed. It was a pandemonium of pain. for, their parched throats softened by the water, they were again able to yelp and cry out loudly all their hurt and woe. She had so indescribably touched and interested me, stranger as I was, that the sudden cessation of her faint, sweet tones affected me almost with a sense of pain . She lay so several hours for the drowse deepened into a heavy sleep, and Uncle Alec, still at his post, saw with growing anxiety that a feverish colour began to burn in her cheeks, that her breathing was quick and uneven, and now and then she gave a little moan, as if in pain . When this shower of arrows was over, I fell a-groaning with grief and pain. and then striving again to get loose, they discharged another volley larger than the first, and some of them attempted with spears to stick me in the sides, but, by good luck, I had on a buff jerkin, which they could not pierce. Its burning, searing pain to love her and leave her--but not to have loved her is unthinkable. Or that again which most nearly approaches to the condition of the individual--as in the body, when but a finger of one of us is hurt, the whole frame, drawn towards the soul as a center and forming one kingdom under the ruling power therein, feels the hurt and sympathizes all together with the part affected, and we say that the man has a pain in his finger and the same expression is used about any other part of the body, which has a sensation of pain at suffering or of pleasure at the alleviation of suffering.