药学英语课本

DevelopingDrugsfromTraditionalMedicinalPlantsOverthreequartersoftheworld'spopulationreliesmainlyonplantsandplantextractsforhealthcare．ApproximatelyonethirdoftheprescriptiondrugsintheUScontainplantcomponents，andmorethan120importantprescriptiondrugsarederivedfromplants．Mostofthesedrugsweredevelopedbecauseoftheiruseintraditionalmedicine．Economically，thisrepresents$8000～10，000Mofannualconsumerspending．RecentWorldHealthOrganization(WHO)studiesindicatethatover30percentoftheworld'splantspecieshaveatonetimeoranotherbeenusedformedicinalpurposes．Ofthe250，000higherplantspeciesonEarth，morethan80，000speciesaremedicinal．Althoughtraditionalmedicineiswidespreadthroughouttheworld，itisanintegralpartofeachindividualculture．Itspracticeisbasedmainlyontraditionalbeliefshandeddownfromgenerationtogenerationforhundredsoreventhousandsofyears．Unfortunately，muchofthisancientknowledgeandmanyvaluableplantsarebeinglostatanalarmingrate．Thescientificstudyoftraditionalmedicinesandthesystematicpreservationofmedicinalplantsarethusofgreatimportance．Forquitealongtime，theonlywaytouseplantmedicineswaseitherdirectapplicationortheuseofcrudeplantextracts．Withthedevelopmentoforganicchemistryatthebeginningofthiscentury，extractionandfractionationtechniquesimprovedsignificantly．Itbecamepossibletoisolateandidentifymanyoftheactivechemicalsfromplants．Inthe1940s，advancesinchemicalsynthesisenabledthesynthesisofmanyplantcomponentsandtheirderivatives．Inwesterncountries，itwasthoughtthatchemicalsynthesisofdrugswouldbemoreeffectiveandeconomicalthanisolationfromnaturalsources．Indeed，thisistrueinmanycases．However，inmanyothercases，syntheticanaloguesarenotaseffectiveastheirnaturalcounterparts．Inadditio，somesyntheticdrugscostmanytimesmorethannaturalones．Inspiredbytheserealisations，coupledwiththefactthatmanydrugswithcomplexstructuresmaybetotallyimpossibletosynthesis，thereisnowaresurgenttrendofreturningtonaturalresourcesfordrugdevelopment．ImportantprescriptiondrugsfromplantsEphedrineistheoldestandmostclassicexampleofaprescriptiondrugdevelopedfromatraditionalmedicinalplant．ItisderivedfromMaHuang，aleaflessshrub．UsedtorelieveasthmaandhayfeverinChinaforover5000years，itwasintroducedintowesternmedicinein1924byChenandSchmidt．Ephedrineisanalkaloidcloselyrelatedtoadrenaline，themajorproductoftheadrenalgland．Pharmacologically，Ephedrineisusedextensivelytostimulateincreasedactivityofthesympatheticnervoussystem．Itisusedasapressoragenttocounteracthypotensionassociatedwithanaesthesia，andasanasaldecongestant．Thedrugactionofthismedicineisbasedbothonitsdirecteffectonαandβadrenergicreceptorsandonthereleaseofendogenousnoradrenaline．Digitalisisoneofthemostfrequentlyusedmedicationsinthetreatmentofheartfailureandarrhythmia．Itincreasesthecontractilityoftheheartmuscleandmodifiesvascularresistance．Italsoslowsconductionthroughtheatrioventricularnodeintheheart，makingitusefulinthetreatmentofatrialfibrillationandotherrapidheartrhythms．DigitalisisfoundintheleavesandseedsofDigitalispurpureaandDigitalislanata，commonlyknownasthefoxgloveplant．Foxglovehasbeenusedintraditionalmedicineinmanypartsoftheworld--byAfricannativesasarrowpoisons，bytheancientEgyptiansasheartmedicine，andbytheRomansasadiuretic，hearttonic，emeticandratpoison．TheChinese，whofoundthisingredientnotonlyinplantsbutalsointhedryskinandvenomofthecommontoad，useditforcenturiesasacardiacdrug．Inthewesternworld，thefoxglovewasfirstmentionedin1250inthewritingofaphysician，Walsh，anditwasdescribedbotanicallyinthe1500s．Digitalisisaglycosidecontaininganaglycone，orgenin，linkedtobetweenoneandfoursugarmolecules．Thepharmacologicalactivityresidesintheaglycone，whereasthesugarresiduesaffectthesolubilityandpotencyofthedrug．Theaglyconeisstructurallyrelatedtobileacids，sterols，sexhormonesandadrenocorticalhormones．d-Tubocurarineanditsderivativesarethemostfrequentlyuseddrugsinoperatingroomstoprovidemusclerelaxationandpreventmusclespasm．Theseagentsinterruptthetransmissionofthenerveimpulseattheskeletalneuromuscularjunction．Curare，thecommonnameforSouthAmericanarrowpoisons，hasalongandinterestinghistory．IthasbeenusedforcenturiesbyIndiansalongtheAmazonandOrinocoriversforhunting．Itcausesparalysisoftheskeletalmusclesofanimalsandfinallyresultsindeath．Themethodsofcurarepreparationwereasecretentrustedonlytotribaldoctors．SoonaftertheirdiscoveryoftheAmericancontinent，Europeanexplorersbecameinterestedincurare．Inthelate16thcentury，samplesofnativepreparationswerebroughttoEuropeforinvestigation．Curare，analkaloid，wasfoundinvariousspeciesofStrychnosandcertainspeciesofChondrodendron．Thefirstuseofcurareformusclerelaxationwasreportedin1942byGriffithandJohnson．Thisdrugoffersoptimalmuscularrelaxationwithouttheuseofhighdosesofanaesthetics．Itthusemergedasthechiefdrugforuseintrachealintubationandduringsurgery．VinblastineandVincristinearetwoofthemostpotentantitumourdrugs．TheyareobtainedfromCatharanthusroseus，commonlyknownastherosyperiwinkle．Thisplant，indigenoustoMadagascar，isalsocultivatedinIndia，IsraelandtheUS．Itwasoriginallyexaminedforclinicalusebecauseofitstraditionaluseintreatingdiabetes．Theleavesandrootsofthisplantcontainmorethan100alkaloids．Fractionationoftheseextractsyieldsfouractivealkaloids：Vinblastine，Vincristine，VinleurosineandVinresidine．Thesealkaloidsareasymmetricdimericcompoundsreferredtoasvincaalkaloids，butofthese，onlyVinblastineandVincristineareclinicallyimportantantitumouragents．Thesetwoalkaloidsarecell-cyclespecificagentsthatblockmitosis(celldivision)．Vincristinesulphateisusedtotreatacuteleukaemiainchildrenandlymphocyticleukaemia．ItisalsoeffectiveagainstWilm'stumour，neuroblastoma，rhabdomyosarcoma(tumourofvoluntaryorstripedmusclecells)，reticulumcellsarcomaandHodgkin'sdisease．VinblastinesulphateisusedinthetreatmentofHodgkin'sdisease，lymphosarcoma，choriocarcinoma，neuroblastoma，carcinomaofbreast，lungandotherorgans，andinacuteandchronicleukaemia．EmergingplantmedicinesArtemisininisthemostrecentanti-malariadrugdevelopedfromplant-basedtraditionalmedicine．ItisisolatedfromtheleavesandflowersofArtemisiaannuaL．(Compositae)，commonlyknownasthesweetwormwood，acousinoftarragon．IndigenoustoChina，theextractofthisplantistraditionallyknownastheQinghao．IthasbeenusedtotreatmalariainChinaforover2000years．Itsactivecomponent，Artemisinin，wasfirstisolatedinthe1970sbyChinesescientists．UnlikeQuinineandChloroquine，thiscompoundisnon-toxicrapidineffect，andsafeforpregnantwomen．Furthermore，itiseffectiveagainstchloroquine-resistantPlasmodiumfalciparummalariaandinpatientswithcerebralmalaria．Itkillstheparasitesdirectlysoparasitemiaisquicklycontrolled．ThisworkwasconfirmedbytheWHOinAfricaandotherpartsofSoutheastAsia．Artemisininisanendoperoxideofthesesquiterpenelactone．Thestructureofthiscompoundistoocomplextobesynthesisedeffectively．ArtemisiaisalsofoundinmanypartsoftheUS，abundantlyalongthePotomacRiverinWashingtonDC，butthedrugcontentofthesevarietiesisonlyabouthalfthatoftheChinesevariety．Currently，theWHOandtheUSarejointlyengagedinthecultivationofChineseArtemisiaforworldwideuse．Thisrecentdevelopmentoffersrenewedhopeforusingtraditionalmedicinetoprovidenewdrugsforfuturemedicines．1.prescriptionn.处方，药方，规定2.WorldHealthOrganization世界卫生组织(缩写为WHO)3.adrenergica．肾上腺素的，类似肾上腺素的，释放肾上腺素的4.Artemisinin青蒿素5.antimalarian．抗疟疾，防疟疾6.fractionationn．分馏7.counterpartn．配对物，副本，极相似的人或物8.resurgenta．复活的，苏醒的，恢复活力的9.asthman．哮喘10.adrenaln.肾上腺;a.肾上腺的11.glandn.腺12.pharmacologicallyad．药理地，药学地，药用地13.pressorn．升高血压的物质a.有使血压增高的，收缩血管的14.hypotensionn．低血压15.anaesthesian．麻醉(法)，感觉缺乏，麻木16.nasala．鼻的，护鼻的，鼻音的n．鼻音，鼻音宇17.endogenousa.内生的，内长的18.noradrenalinen.=norepinephrine去甲肾上腺素19.digitalisn．洋地黄20.arrhythmian．心律不齐21.contractilityn．收缩性，缩小性，伸缩力22.vasculara．脉管的，血管的，有脉管的23.atrioventriculara．房室的，心房与心室的24.noden．结25.atriala．心房的，有关心房的26.fibrillationn．纤维性颤动27.Digitalispurpurea紫花毛地黄28.Digitalislanata毛花洋地黄29.foxgloven．毛地黄30.diureticn．利尿剂;a．利尿的31.ahearttonic强心药32.venomn．毒液33.toadn．蟾蜍，癞蛤蟆34.cardiacn．强心剂，强胃剂;a．心脏的，(胃的)贲门的35.botanicallyad．植物(学)地36.glycosiden．苷，配糖类，配糖物37.aglyconen．配质，配基，(苷的)非糖部38.geninn．配质，配基39.solubilityn．溶(解)度，溶(解)性，(可)溶性40.potencyn．效力，效验，能力，潜力，力量41.bileacid胆汁酸42.steroln．甾醇，固醇43.sexhormone性激素44.adrenocorticalhormonen．肾上腺皮质激素45.digoxigeninn．异羟基洋地黄毒苷，地谷新配质46.digitoxigeninn．毛地黄毒苷配基，户(丁烯酸内酯)-14-羟甾醇47.d-tubocurarinen．d-管箭毒碱48.relaxationn．松弛，缓和，减轻，放宽49.spasmn．痉挛，一阵发作50.skeletala．骨骼的，骸骨的51.neuromusculara．神经肌肉的52.curaren．箭毒，马钱子属植物，马钱子(也叫番木鳖)53.paralysisn．瘫痪，麻痹54.entrustedvt.委托，托管，信托55.Strychnosn．[S-]马钱子属，毒鼠碱56.Chondrodendronn.南美防己属57.tracheala．气管的，导管的，呼吸管的58.intubationn．插管，插管法59.Vinblastinen．长春碱60.Vincristinen．长春新碱61.antitumourn.抗癌的，抗肿瘤的62.Catharanthusroseus长春花63.periwinklen．长春花属的植物，玉黍螺64.indigenousa．本土的65.Madagascarn．马达加斯加岛(非洲岛国)66.diabetesn．糖尿病，多尿症67.Vinleurosinen．环氧长春碱68.Vinresidinen．(＝leurosidine)异长春碱，洛诺西丁69.asymmetrica．不对称的，不均匀的70.dimerica．二聚的，形成二聚物的71.vincan．长春花72.Vincristinesulphate硫酸长春新碱73.acutea．急性的，敏锐的74.chronica.慢性的，延续很长的75.leukaemian．白血病76.lymphocytica．淋巴球的，淋巴细胞的77.neuroblastoman.成神经细胞瘤78.rhabdomyosarcoman．横纹肌肉瘤79.stripedn．有斑纹的80.sarcoman．肉瘤，恶性毒瘤81.lymphosarcoman．淋巴肉瘤82.choriocarcinoman．绒膜癌83.carcinoma([复]carcinomas或carcinomata)n.癌84.anti-malarian．抗疟疾85.ArtemisiaannuaL黄花蒿屑植物，青蒿属植物86.Compositaen．菊科87.wormwoodn．蒿属植物88.tarragonn．龙蒿，龙蒿叶89.malarian．疟疾，瘴气90.Quininen．奎宁91.Chloroquinen．氯喹92.Plasmodiumfalciparum恶性疟原虫，镰状疟原虫93.cerebrala．脑的，大脑的94.parasiten．寄生虫，食客95.parasitemian．寄生虫血症96.endoperoxiden．桥过氧化物97.sesquiterpenen．倍半萜烯98.lactonen．内酯TheAutonomicandCentralNervousSystems(Ⅰ)Allchemicalsubstancesthathaveapotentialforabuseproducetheirdesirable(andoftenundesirable)effectsbymechanismsinvolvingthenervoussystem.Tounderstandhowabusedsubstancesproducetheirsought-aftereffectsandwhyvariousmodalitiesareusedtotreattheirtoxicmanifestations,abasicknowledgeofthestructureandfunctionofthenervoussystemisnecessary.Thefollowingoverviewpresentsthemajorcomponentsofthenervoussystemandtheirfunctions.Thisinformationisnotintendedasacomprehensivereviewofneuroanatomy,butratherasabasisforunderstandingthedrug-relatedmaterialtobepresentedinlaterchaptersinthistext.Additionalinformationmaybeobtainedfromthereferencesandselectedreadingslistedattheendofthischapter.Anatomically,thenervoussystemisdividedintotwomajorcomponents:thecentralnervoussystem(CNS)andtheperipheralnervoussystem.TheCNS,composedofthebrainandspinalcord,isresponsibleforintegrativefunctionsrelatedtobothconsciousandsubconsciousactivitiesofthebody.Itisalsoultimatelyresponsiblefortheinterpretationof,andreactionto,allinformationthatthebodyreceivesfromtheenvironment.TheperipheralnervoussystemismadeupofnervefibersthatconductinformationtowardtheCNS(afferentfibers)andnervefibersthatconductdirectivesfromtheCNStoallbodyareas(efferentfibers).Beforeundertakingageneraldiscussionofthenervoussystem,abriefreviewofthebasicunitofthenervoussystem,theneuron,andthemechanismsbywhichinformationistransferredthroughoutthenervoussystemisinorder.TheNeuronTheneuron,ornervecell,isthebaseofallactivitiesofthenervoussystem.Neuronsdifferfromotherbodycellsintworespects:(1)theycanconductinformationintheformofelectricalimpulsesoverlongdistances;and(2)theyrelatetoothernervecellsandinnervatedtissueinahighlyspecializedmanner.Theneuronconsistsofacellbody,anaxon,whichcarriesinformationawayfromthecellbody,andoneormoredendrites,whichcarryinformationtowardthecellbody.Someaxonsaresurroundedbyalayeroffattytissuecalledamyelinsheath,whichdevelopswithinthenervoussystemoveraperiodofyearsandservesasaprotectivecoating.Theabilityoftheneurontotransmitinformationfromonesitetoanotherisafunctionofitselectricaltransmissioncapabilityanditscapacitytosynthesize,store,andreleasehighlyspecificchemicals(neurotransmitters)fromnerveendings.Thesitewheretwonerveendingsmeetorwhereanervemeetsthetissuethatitinnervatesisasmallgapthatistermedthesynapse,orsynapticcleft.Inorderforelectricalimpulsestocrossasynapse,aneurotransmitterisreleasedfromonenerveendingtotravelacrossthesynapseandstimulatereceptorsonanadjacentnerveortissue.ThePeripheralNervousSystemTheperipheralnervoussystemconsistsofallthenervefibersthatconductinformationtoandfromtheCNSandthatlieoutsidethebrainandspinalcord.Peripheralafferentfibersareinvolvedwithsensationssuchaspain,temperature,andtouch,whereasperipheralefferentfibersareinvolvedwiththecontrolofspecificbodyfunctions.Efferentfibersaredividedintotwocategories:(1)somaticfibers,whichcontrolthefunctionofskeletalmuscle,and(2)autonomicfibers,whichcontroltheactivitiesofsmoothmuscle,cardiacmuscle,andglandsofexcretion.Somaticnervefibersleavethespinalcordatvariouslevels,dependingonthelocationoftheinnervatedskeletalmuscle,andcontinueasanuninterruptedunitfromtheirsiteoforigin(motorneuron)toskeletalmuscletissue.Thesiteatwhichthesomaticfibermeetstheskeletalmuscleistermedtheneuromuscularjunction(NMJ).TheneurotransmitterattheNMJisacetylcholine.Autonomicefferentfiberscontroltheautomaticorsubconsciousfunctioningofsmoothandcardiacmuscleandexocrineglands.Thesefibersareresponsibleforactivitiessuchasthemaintenanceoftoneinthegastrointesitinaltractandbloodvessels,regulationofheartrateandreleaseofsubstancessuchassaliva,respiratorysecretions,andgastricacid.Autonomicfibertractsactuallyconsistoftwoseparatefibers.Thefirstfiber(presynapticfiber)originatesinsidethespinalcordandterminatesatasynapsesomewhereintheperiphery.Thesecondfiber(postsynapticfiber)originatesatthesynapseandterminatesattheinnervatedtissue.Inmostinstances,thesynapsesofanumberoffibersaregroupedtogetherandtermedaganglion.Insuchcases,thepresynapticandpostsynapticfibersarereferredtoaspreganglionicandpostglanglionicfibers,respectively.Thesiteatwhichthepostganglionicfibersynapseswiththeinnervatedtissueistermedtheneuroeffectorjunction(NEJ).Autonomicfibersarecategorizedbytwomethods.ThefirstandoldermethodofclassificationisbasedonthesitesatwhichpreganglionicfibersleavetheCNS.Nervesthatexitfromthethoracicandlumbarlevelsofthespinalcordaretermedsympathetic,whereasthosethatexitfromthesacrallevelofthespinalcordandcraniumaretermedparasympathetic.ThesecondmethodofclassificationisbasedontheneurotransmitterreleasedattheNEJbythenervefiber.Nervesthatreleaseacetylcholine(Ach)aretermedcholinergic,whereasthosethatreleasenorepinephrine(NE)aretermedadrenergic.Ingeneral,thetermsympatheticisinterchangeablewithadrenergicandthetermparasympatheticisinterchangeablewithcholinergic.Cholinergicandadrenergicareusuallythepreferredtermswhendiscussingdrugeffectsonautonomicfunctionbecausetheydesignatethespecificneurotransmittersaffectedbythedrugs.Withintheautonomicnervoussystem(ANS),receptorsitesforAchandNEhaveaveryspecificnomenclaturebasedupontheirlocationandfunction.Cholinergicreceptorsitesarefoundintheganglionicsynapsesofboththesympatheticandparasympatheticnervoussystem.TheyarealsofoundattheNEJofparasympatheticfibers.Cholinergicreceptorsitesarecategorizedasbeingeithermuscarinicornicotinic,basedonwhethertheyrespondtothealkaloidsmuscarineornicotine,respectively.MuscarinicreceptorsarefoundattheparasympatheticNEJ.NicotinicreceptorsarefoundatallautonomicgangliaandatthesomaticNMJ.AdrenergicreceptorsitesintheANSarefoundonlyatthesympatheticNEJ.Adrenergicreceptorsaredividedintothreecategories:alpha,beta1,andbeta2.Ingeneral,stimulationofthealphaadrenergicreceptorsitecausesanincreaseinactivityoftheinnervatedtissue.Alphareceptorsarefoundprimarilyinarteriolesandthereforeareimportantinthemaintenanceofbloodpressure.StimulationofalphareceptorsbyNEleadstoarteriolarconstriction,whichincreasesbloodpressure.Beta1receptorsarefoundonlyincardiactissue.Stimulationofthesereceptorsleadstoanincreaseinheartrate.Beta2receptorsarefoundatvarioussitessuchasinbronchialsmoothmuscleandinbloodvesselsofskeletalmuscle.Stimulationofbeta2receptorsleadstorelaxationoftheinnervatedtissue,thatis,stimulationofbeta2receptorsinbronchialsmoothmuscleproducesrelaxationandincreasestheabilitytoinhaleair.Theparasympatheticnervoussystemcontrolssubconsciousactivityduringperiodsofrelaxation.Underparasympatheticcontrol,heartrateisdecreasedasaremostotherbodyfunctions;however,gastrointestinalactivityisincreasedtofacilitatethedigestionoffood.Thesympatheticnervoussystemcontrolsthebodyduringperiodsofactivity.Followingstimulationofadrenergicreceptors,heartrateandbloodpressureincrease,bloodflowtoskeletalmuscleisincreased,airintakeisfacilitated,andparasympatheticfunctionsaredepressed.Activationofsympatheticfunctionshasbeentermedthefightorflightmechanismbecauseitpreparesthebodyforahighlevelofactivity.Epinephrine,anotherneurotransmitter,playsakeyroleinthestimulationofadrenergicreceptorsforvigorousactivity.Epinephrineisreleasedduringperiodsofstressfromtheadrenalglandandistransportedviathecirculatorysystemthroughoutthebody(includingtheCNS)toincreaseadrenergicactivity.TheCentralNervousSystemTheCNSservesasthecontrolcenterforallbodyfunctionsatboththeconsciousandsubconsciouslevels.Thus,allinformationperceivedbythebodyisultimatelytransmittedtotheCNSforinterpretation,allbodyfunctionsareintegrandwithintheCNS,andallactivitiesofthebodyarecontrolledfromtheCNS.TheCNSconsistsofthespinalcordandthebrain.Thespinalcordisacollectionofafferentandefferentfibersthataresurroundedandprotectedbythespine.Withinthespinalcord,nerveswithsimilarfunctionsornervesthatoriginateorterminateinthesamesitesarefoundintracts.Thespinalcordalsocontainsnuclei,whicharefunctionallythesameasautonomicganglia.Thehumanbrainisthesiteofcontrolofbodyfunction;italsohasthecapabilitytothink,reason,originateanddisplayemotion,andinteractwithaconstantlychangingenvironment.Thebrainiscomposedofanumberofdiscreteareas,someofwhichfunctionrelativelyindependently(structures)andsomeofwhichfunctioninanintegratedfashionwithotherbrainareas(systems).Forthepurposesofthisoverview,thebrainstructureswillbediscussedfirst,followedbyabriefreviewofthesystems.Theprimarystructuresofthebrainincludethecerebralcortex,thalamus,hypothalamus,medulla,andpons.Theprimarysystemsarethelimbicsystem,extrapyramidalsystem,andreticularactivatingsystem.Thereissomefunctionaloverlapbetweenthebrainstructuresandthebrainsystems.Thisoverlapwillbeconsideredinthediscussionofthesystems.Thecerebralcortexisathinlayerofcellscoveringtheoutsideofthebrainhemispheres.Thecortexisconsideredtobetheseatofconsciousactivityandbehaviorcontrol.Itisinvolvedwiththeabilitytothink,reason,learn,andremember,andservesasthehighestlevelofintegrationforallbodyfunctions.Thecortexisalsoinvolvedwiththeprimarycontrolofskeletalmusclefunctionandtheinterpretationofsensations.Itisdividedintofourareasorlobes,eachofwhichisinvolvedinspecificfunctions.Thefrontallobeisinvolvedinpyramidalskeletalmusclecontrol,abstractthought,andsomeemotionalresponding.Thetemporallobeisinvolvedintheinterpretationofauditorystimulationandsomeemotionalresponses.Theoccipitallobeisinvolvedinvisualinterpretation,andtheparietallobeisinvolvedininterpretationofsensations,orientationtotimeandspace,andlanguagediscrimination.TheprimaryneurotransmitterofthecortexappearstobeNE.Thecortexistheareaofthebrainmostsensitivetotheactionsofmanydrugs.Nonspecificdepressantssuchasthebarbituratesproducesedation,ataxia,andslurredspeechbecauseoftheircorticaleffects.Stimulantssuchasamphetamineandcocaineproducearousalbyaffectingcorticalfunctioneitherbyadirectactiononcorticalneuronsorbystimulationoffibertractsthataffectcorticalfunction.Locatedwithinthecerebralhemispheresareanumberofstructuresinvolvedwithmanydiversefunctions.Thethalamus,epithalamus,subthalamus,andhypothalamusarelocatedintheareatermedthemidbrain.Thethalamusiscomposedofanumberofnucleithatactasrelaystationsforinformationpassingbetweenthecortexandotherbrainareasandperipheralsites.Theepithalamuscontainssomenucleiinvolvedwitholfactorysensationsandthepinealgland,whichisinvolvedwithbiochemicalresponsestolight,circadianrhythms,andhormonalcontrolofsexualdevelopment.Thesubthalamusisassociatedwiththeintegrationofsomeextrapyramidalsystemfunctionsandcontainsfibertractsconnectingotherareasofthemidbrain.Althoughmanydrugsmayaffectthefunctionofthesestructuresnonspecifically,theopioidanalgesicsappeartoproduceatleastpartoftheiranalgesicactivitybyblockingthetransmissionofpainimpulsesbetweenthethalamusandthesensorycortex.Thehypothalamusismadeupofalargemassofnucleiandservesanumberofdiversefunctions.ItisthehighestlevelofintegrationfortheANSandservesastheoutputsystemforemotiongeneratedviathelimbicsystem.Itregulatesendoc