Class Notes- Exam Preparation Notes On Physiology Of Pain

PhysiologyofPainIntroduction:Painisdefinedasunpleasantandemotionalexperienceassociatedwithorwithoutactualtissuedamage.pain1-Acute-short,sharp,withinsmallarea.I-chronic-constant,withdifferentintensitiesandlastslonger.Paininanimportantprotectiveunpleasantsensationwithsurvivalbenefits.Painsensationhastwocomponents:(asFastpain-firstsensation,bright.sharp&localized.CarriedbyAstypenervefibres.cbsslowpain-Dull.diffused&UnpleasantandcarriedbyCtypeNervefibresPathwaysofPainsensation:itsFromskin&deeperstructures(2)Fromface-carriedbyTr i g e m i n a lNerve131FromViscera-ByThorawlumbar.Va g u s&Glossopharyngeal(41FromPelvicregion-sacralparasympatheticnerves.Fromskin&deeperstructures:Receptorogpainarefreenerveendingswhicharedistributedthroughoutbody.Firstorderneurons-Theyarecellsinposteriornerverootganglia,whichreceivetheimpulsesogpainsensationfrompainreceptorstospinalcord.fastpainsensation(byAs)synapsewithneuronsogMarginalNucleusinposteriorgrayhorn-Slowpainsensation(byctype)synapsewithSubstantiagelatinosagRolandoinpost.grayhorn.ulceretc)(3)Spasm&Overdistention.ReferredPainItinthepainthatinperceivedatasiteadjacenttoorawayfromthesiteoforigin..DeeppainandVisceralpainarereferredtootherarea,notsuperficialpain..Exempla:(atCardiacpaininfeltinleftArm&shoulder.(biRaininOvaryUmbilicuscc,PaininTe s t i sinfeltinabdomen(d'Painindiaphragmshoulderee,PainingallbladderEpigastricRegionif,Renalpaininreferredtoloin.AlctodermatonalRule-thereason/mechanismgreferredpaininpaininreferredtoastructure,whichwedevelopedfromsamedermatomefromwhichthepainproducingstructureisdeveloped.NeurotransmittersInvolved:Glutamate&substancePamtheneurotransmitterssecretedbypainnerveendings.Astype=GlutamateCtype--substancePAnalgesiaSystemAnalgesiasystemmeansthepaincontrolsystem..9TinalsocalledEndogenousanalgesicsystem.Analgesiasystemhasgotitsownpathwaythroughwhichitblocksthesynaptictransmissiongpainsensationinspinalcordandthusreducesthepain.Analgesicdrugssuchasopioidsactsthroughthissystemandproviderelief.Rig-showingAnalgesicPathway.AppliedinAnalgesia:lossofpainsensation.121Hyperalgesia:Increasedsensitivitytopainsensation.types:Primary-SecretaryHyperalgesiaIIParalgesia:Abnormalpainsensation.Extras:MedNotes*notes.in)