Developing Drugs from Traditional Medicinal Plants.doc

1、DEVELOPINGDRUGSFROMTRADITIONALMEDICINALPLANTSOVERTHREEQUARTERSOFTHEWORLDSPOPULATIONRELIESMAINLYONPLANTSANDPLANTEXTRACTSFORHEALTHCAREAPPROXIMATELYONETHIRDOFTHEPRESCRIPTIONDRUGSINTHEUSCONTAINPLANTCOMPONENTS，ANDMORETHAN120IMPORTANTPRESCRIPTIONDRUGSAREDERIVEDFROMPLANTSMOSTOFTHESEDRUGSWEREDEVELOPEDBECAUS

2、EOFTHEIRUSEINTRADITIONALMEDICINEECONOMICALLY，THISREPRESENTS800010，000MOFANNUALCONSUMERSPENDINGRECENTWORLDHEALTHORGANIZATIONWHOSTUDIESINDICATETHATOVER30PERCENTOFTHEWORLDSPLANTSPECIESHAVEATONETIMEORANOTHERBEENUSEDFORMEDICINALPURPOSESOFTHE250，000HIGHERPLANTSPECIESONEARTH，MORETHAN80，000SPECIESAREMEDICIN

3、ALALTHOUGHTRADITIONALMEDICINEISWIDESPREADTHROUGHOUTTHEWORLD，ITISANINTEGRALPARTOFEACHINDIVIDUALCULTUREITSPRACTICEISBASEDMAINLYONTRADITIONALBELIEFSHANDEDDOWNFROMGENERATIONTOGENERATIONFORHUNDREDSOREVENTHOUSANDSOFYEARSUNFORTUNATELY，MUCHOFTHISANCIENTKNOWLEDGEANDMANYVALUABLEPLANTSAREBEINGLOSTATANALARMINGR

4、ATETHESCIENTIFICSTUDYOFTRADITIONALMEDICINESANDTHESYSTEMATICPRESERVATIONOFMEDICINALPLANTSARETHUSOFGREATIMPORTANCEFORQUITEALONGTIME，THEONLYWAYTOUSEPLANTMEDICINESWASEITHERDIRECTAPPLICATIONORTHEUSEOFCRUDEPLANTEXTRACTSWITHTHEDEVELOPMENTOFORGANICCHEMISTRYATTHEBEGINNINGOFTHISCENTURY，EXTRACTIONANDFRACTIONAT

5、IONTECHNIQUESIMPROVEDSIGNIFICANTLYITBECAMEPOSSIBLETOISOLATEANDIDENTIFYMANYOFTHEACTIVECHEMICALSFROMPLANTSINTHE1940S，ADVANCESINCHEMICALSYNTHESISENABLEDTHESYNTHESISOFMANYPLANTCOMPONENTSANDTHEIRDERIVATIVESINWESTERNCOUNTRIES，ITWASTHOUGHTTHATCHEMICALSYNTHESISOFDRUGSWOULDBEMOREEFFECTIVEANDECONOMICALTHANISO

6、LATIONFROMNATURALSOURCESINDEED，THISISTRUEINMANYCASESHOWEVER，INMANYOTHERCASES，SYNTHETICANALOGUESARENOTASEFFECTIVEASTHEIRNATURALCOUNTERPARTSINADDITIO，SOMESYNTHETICDRUGSCOSTMANYTIMESMORETHANNATURALONESINSPIREDBYTHESEREALISATIONS，COUPLEDWITHTHEFACTTHATMANYDRUGSWITHCOMPLEXSTRUCTURESMAYBETOTALLYIMPOSSIBLE

7、TOSYNTHESIS，THEREISNOWARESURGENTTRENDOFRETURNINGTONATURALRESOURCESFORDRUGDEVELOPMENTIMPORTANTPRESCRIPTIONDRUGSFROMPLANTSEPHEDRINEISTHEOLDESTANDMOSTCLASSICEXAMPLEOFAPRESCRIPTIONDRUGDEVELOPEDFROMATRADITIONALMEDICINALPLANTITISDERIVEDFROMMAHUANG，ALEAFLESSSHRUBUSEDTORELIEVEASTHMAANDHAYFEVERINCHINAFOROVER

8、5000YEARS，ITWASINTRODUCEDINTOWESTERNMEDICINEIN1924BYCHENANDSCHMIDTEPHEDRINEISANALKALOIDCLOSELYRELATEDTOADRENALINE，THEMAJORPRODUCTOFTHEADRENALGLANDPHARMACOLOGICALLY，EPHEDRINEISUSEDEXTENSIVELYTOSTIMULATEINCREASEDACTIVITYOFTHESYMPATHETICNERVOUSSYSTEMITISUSEDASAPRESSORAGENTTOCOUNTERACTHYPOTENSIONASSOCIA

9、TEDWITHANAESTHESIA，ANDASANASALDECONGESTANTTHEDRUGACTIONOFTHISMEDICINEISBASEDBOTHONITSDIRECTEFFECTONANDADRENERGICRECEPTORSANDONTHERELEASEOFENDOGENOUSNORADRENALINEDIGITALISISONEOFTHEMOSTFREQUENTLYUSEDMEDICATIONSINTHETREATMENTOFHEARTFAILUREANDARRHYTHMIAITINCREASESTHECONTRACTILITYOFTHEHEARTMUSCLEANDMODI

10、FIESVASCULARRESISTANCEITALSOSLOWSCONDUCTIONTHROUGHTHEATRIOVENTRICULARNODEINTHEHEART，MAKINGITUSEFULINTHETREATMENTOFATRIALFIBRILLATIONANDOTHERRAPIDHEARTRHYTHMSDIGITALISISFOUNDINTHELEAVESANDSEEDSOFDIGITALISPURPUREAANDDIGITALISLANATA，COMMONLYKNOWNASTHEFOXGLOVEPLANTFOXGLOVEHASBEENUSEDINTRADITIONALMEDICIN

11、EINMANYPARTSOFTHEWORLDBYAFRICANNATIVESASARROWPOISONS，BYTHEANCIENTEGYPTIANSASHEARTMEDICINE，ANDBYTHEROMANSASADIURETIC，HEARTTONIC，EMETICANDRATPOISONTHECHINESE，WHOFOUNDTHISINGREDIENTNOTONLYINPLANTSBUTALSOINTHEDRYSKINANDVENOMOFTHECOMMONTOAD，USEDITFORCENTURIESASACARDIACDRUGINTHEWESTERNWORLD，THEFOXGLOVEWAS

12、FIRSTMENTIONEDIN1250INTHEWRITINGOFAPHYSICIAN，WALSH，ANDITWASDESCRIBEDBOTANICALLYINTHE1500SDIGITALISISAGLYCOSIDECONTAININGANAGLYCONE，ORGENIN，LINKEDTOBETWEENONEANDFOURSUGARMOLECULESTHEPHARMACOLOGICALACTIVITYRESIDESINTHEAGLYCONE，WHEREASTHESUGARRESIDUESAFFECTTHESOLUBILITYANDPOTENCYOFTHEDRUGTHEAGLYCONEISS

13、TRUCTURALLYRELATEDTOBILEACIDS，STEROLS，SEXHORMONESANDADRENOCORTICALHORMONESDTUBOCURARINEANDITSDERIVATIVESARETHEMOSTFREQUENTLYUSEDDRUGSINOPERATINGROOMSTOPROVIDEMUSCLERELAXATIONANDPREVENTMUSCLESPASMTHESEAGENTSINTERRUPTTHETRANSMISSIONOFTHENERVEIMPULSEATTHESKELETALNEUROMUSCULARJUNCTIONCURARE，THECOMMONNAM

14、EFORSOUTHAMERICANARROWPOISONS，HASALONGANDINTERESTINGHISTORYITHASBEENUSEDFORCENTURIESBYINDIANSALONGTHEAMAZONANDORINOCORIVERSFORHUNTINGITCAUSESPARALYSISOFTHESKELETALMUSCLESOFANIMALSANDFINALLYRESULTSINDEATHTHEMETHODSOFCURAREPREPARATIONWEREASECRETENTRUSTEDONLYTOTRIBALDOCTORSSOONAFTERTHEIRDISCOVERYOFTHEA

15、MERICANCONTINENT，EUROPEANEXPLORERSBECAMEINTERESTEDINCURAREINTHELATE16THCENTURY，SAMPLESOFNATIVEPREPARATIONSWEREBROUGHTTOEUROPEFORINVESTIGATIONCURARE，ANALKALOID，WASFOUNDINVARIOUSSPECIESOFSTRYCHNOSANDCERTAINSPECIESOFCHONDRODENDRONTHEFIRSTUSEOFCURAREFORMUSCLERELAXATIONWASREPORTEDIN1942BYGRIFFITHANDJOHNS

16、ONTHISDRUGOFFERSOPTIMALMUSCULARRELAXATIONWITHOUTTHEUSEOFHIGHDOSESOFANAESTHETICSITTHUSEMERGEDASTHECHIEFDRUGFORUSEINTRACHEALINTUBATIONANDDURINGSURGERYVINBLASTINEANDVINCRISTINEARETWOOFTHEMOSTPOTENTANTITUMOURDRUGSTHEYAREOBTAINEDFROMCATHARANTHUSROSEUS，COMMONLYKNOWNASTHEROSYPERIWINKLETHISPLANT，INDIGENOUST

17、OMADAGASCAR，ISALSOCULTIVATEDININDIA，ISRAELANDTHEUSITWASORIGINALLYEXAMINEDFORCLINICALUSEBECAUSEOFITSTRADITIONALUSEINTREATINGDIABETESTHELEAVESANDROOTSOFTHISPLANTCONTAINMORETHAN100ALKALOIDSFRACTIONATIONOFTHESEEXTRACTSYIELDSFOURACTIVEALKALOIDSVINBLASTINE，VINCRISTINE，VINLEUROSINEANDVINRESIDINETHESEALKALO

18、IDSAREASYMMETRICDIMERICCOMPOUNDSREFERREDTOASVINCAALKALOIDS，BUTOFTHESE，ONLYVINBLASTINEANDVINCRISTINEARECLINICALLYIMPORTANTANTITUMOURAGENTSTHESETWOALKALOIDSARECELLCYCLESPECIFICAGENTSTHATBLOCKMITOSISCELLDIVISIONVINCRISTINESULPHATEISUSEDTOTREATACUTELEUKAEMIAINCHILDRENANDLYMPHOCYTICLEUKAEMIAITISALSOEFFEC

19、TIVEAGAINSTWILMSTUMOUR，NEUROBLASTOMA，RHABDOMYOSARCOMATUMOUROFVOLUNTARYORSTRIPEDMUSCLECELLS，RETICULUMCELLSARCOMAANDHODGKINSDISEASEVINBLASTINESULPHATEISUSEDINTHETREATMENTOFHODGKINSDISEASE，LYMPHOSARCOMA，CHORIOCARCINOMA，NEUROBLASTOMA，CARCINOMAOFBREAST，LUNGANDOTHERORGANS，ANDINACUTEANDCHRONICLEUKAEMIAEMER

20、GINGPLANTMEDICINESARTEMISININISTHEMOSTRECENTANTIMALARIADRUGDEVELOPEDFROMPLANTBASEDTRADITIONALMEDICINEITISISOLATEDFROMTHELEAVESANDFLOWERSOFARTEMISIAANNUALCOMPOSITAE，COMMONLYKNOWNASTHESWEETWORMWOOD，ACOUSINOFTARRAGONINDIGENOUSTOCHINA，THEEXTRACTOFTHISPLANTISTRADITIONALLYKNOWNASTHEQINGHAOITHASBEENUSEDTOT

21、REATMALARIAINCHINAFOROVER2000YEARSITSACTIVECOMPONENT，ARTEMISININ，WASFIRSTISOLATEDINTHE1970SBYCHINESESCIENTISTSUNLIKEQUININEANDCHLOROQUINE，THISCOMPOUNDISNONTOXICRAPIDINEFFECT，ANDSAFEFORPREGNANTWOMENFURTHERMORE，ITISEFFECTIVEAGAINSTCHLOROQUINERESISTANTPLASMODIUMFALCIPARUMMALARIAANDINPATIENTSWITHCEREBRA

22、LMALARIAITKILLSTHEPARASITESDIRECTLYSOPARASITEMIAISQUICKLYCONTROLLEDTHISWORKWASCONFIRMEDBYTHEWHOINAFRICAANDOTHERPARTSOFSOUTHEASTASIAARTEMISININISANENDOPEROXIDEOFTHESESQUITERPENELACTONETHESTRUCTUREOFTHISCOMPOUNDISTOOCOMPLEXTOBESYNTHESISEDEFFECTIVELYARTEMISIAISALSOFOUNDINMANYPARTSOFTHEUS，ABUNDANTLYALON

23、GTHEPOTOMACRIVERINWASHINGTONDC，BUTTHEDRUGCONTENTOFTHESEVARIETIESISONLYABOUTHALFTHATOFTHECHINESEVARIETYCURRENTLY，THEWHOANDTHEUSAREJOINTLYENGAGEDINTHECULTIVATIONOFCHINESEARTEMISIAFORWORLDWIDEUSETHISRECENTDEVELOPMENTOFFERSRENEWEDHOPEFORUSINGTRADITIONALMEDICINETOPROVIDENEWDRUGSFORFUTUREMEDICINES1PRESCRI

24、PTIONN处方，药方，规定2WORLDHEALTHORGANIZATION世界卫生组织缩写为WHO3ADRENERGICA肾上腺素的，类似肾上腺素的，释放肾上腺素的4ARTEMISININ青蒿素5ANTIMALARIAN抗疟疾，防疟疾6FRACTIONATIONN分馏7COUNTERPARTN配对物，副本，极相似的人或物8RESURGENTA复活的，苏醒的，恢复活力的9ASTHMAN哮喘10ADRENALN肾上腺A肾上腺的11GLANDN腺12PHARMACOLOGICALLYAD药理地，药学地，药用地13PRESSORN升高血压的物质A有使血压增高的，收缩血管的14HYPOTENSIONN

25、低血压15ANAESTHESIAN麻醉法，感觉缺乏，麻木16NASALA鼻的，护鼻的，鼻音的N鼻音，鼻音宇17ENDOGENOUSA内生的，内长的18NORADRENALINENNOREPINEPHRINE去甲肾上腺素19DIGITALISN洋地黄20ARRHYTHMIAN心律不齐21CONTRACTILITYN收缩性，缩小性，伸缩力22VASCULARA脉管的，血管的，有脉管的23ATRIOVENTRICULARA房室的，心房与心室的24NODEN结25ATRIALA心房的，有关心房的26FIBRILLATIONN纤维性颤动27DIGITALISPURPUREA紫花毛地黄28DIGITALI

26、SLANATA毛花洋地黄29FOXGLOVEN毛地黄30DIURETICN利尿剂A利尿的31AHEARTTONIC强心药32VENOMN毒液33TOADN蟾蜍，癞蛤蟆34CARDIACN强心剂，强胃剂A心脏的，胃的贲门的35BOTANICALLYAD植物学地36GLYCOSIDEN苷，配糖类，配糖物37AGLYCONEN配质，配基，苷的非糖部38GENINN配质，配基39SOLUBILITYN溶解度，溶解性，可溶性40POTENCYN效力，效验，能力，潜力，力量41BILEACID胆汁酸42STEROLN甾醇，固醇43SEXHORMONE性激素44ADRENOCORTICALHORMONEN肾

27、上腺皮质激素45DIGOXIGENINN异羟基洋地黄毒苷，地谷新配质46DIGITOXIGENINN毛地黄毒苷配基，户丁烯酸内酯14羟甾醇47DTUBOCURARINEND管箭毒碱48RELAXATIONN松弛，缓和，减轻，放宽49SPASMN痉挛，一阵发作50SKELETALA骨骼的，骸骨的51NEUROMUSCULARA神经肌肉的52CURAREN箭毒，马钱子属植物，马钱子也叫番木鳖53PARALYSISN瘫痪，麻痹54ENTRUSTEDVT委托，托管，信托55STRYCHNOSNS马钱子属，毒鼠碱56CHONDRODENDRONN南美防己属57TRACHEALA气管的，导管的，呼吸管的5

28、8INTUBATIONN插管，插管法59VINBLASTINEN长春碱60VINCRISTINEN长春新碱61ANTITUMOURN抗癌的，抗肿瘤的62CATHARANTHUSROSEUS长春花63PERIWINKLEN长春花属的植物，玉黍螺64INDIGENOUSA本土的65MADAGASCARN马达加斯加岛非洲岛国66DIABETESN糖尿病，多尿症67VINLEUROSINEN环氧长春碱68VINRESIDINENLEUROSIDINE异长春碱，洛诺西丁69ASYMMETRICA不对称的，不均匀的70DIMERICA二聚的，形成二聚物的71VINCAN长春花72VINCRISTINESU

29、LPHATE硫酸长春新碱73ACUTEA急性的，敏锐的74CHRONICA慢性的，延续很长的75LEUKAEMIAN白血病76LYMPHOCYTICA淋巴球的，淋巴细胞的77NEUROBLASTOMAN成神经细胞瘤78RHABDOMYOSARCOMAN横纹肌肉瘤79STRIPEDN有斑纹的80SARCOMAN肉瘤，恶性毒瘤81LYMPHOSARCOMAN淋巴肉瘤82CHORIOCARCINOMAN绒膜癌83CARCINOMA复CARCINOMAS或CARCINOMATAN癌84ANTIMALARIAN抗疟疾85ARTEMISIAANNUAL黄花蒿屑植物，青蒿属植物86COMPOSITAEN菊科

30、87WORMWOODN蒿属植物88TARRAGONN龙蒿，龙蒿叶89MALARIAN疟疾，瘴气90QUININEN奎宁91CHLOROQUINEN氯喹92PLASMODIUMFALCIPARUM恶性疟原虫，镰状疟原虫93CEREBRALA脑的，大脑的94PARASITEN寄生虫，食客95PARASITEMIAN寄生虫血症96ENDOPEROXIDEN桥过氧化物97SESQUITERPENEN倍半萜烯98LACTONEN内酯THEAUTONOMICANDCENTRALNERVOUSSYSTEMSALLCHEMICALSUBSTANCESTHATHAVEAPOTENTIALFORABUSEPROD

31、UCETHEIRDESIRABLEANDOFTENUNDESIRABLEEFFECTSBYMECHANISMSINVOLVINGTHENERVOUSSYSTEMTOUNDERSTANDHOWABUSEDSUBSTANCESPRODUCETHEIRSOUGHTAFTEREFFECTSANDWHYVARIOUSMODALITIESAREUSEDTOTREATTHEIRTOXICMANIFESTATIONS,ABASICKNOWLEDGEOFTHESTRUCTUREANDFUNCTIONOFTHENERVOUSSYSTEMISNECESSARYTHEFOLLOWINGOVERVIEWPRESENTS

32、THEMAJORCOMPONENTSOFTHENERVOUSSYSTEMANDTHEIRFUNCTIONSTHISINFORMATIONISNOTINTENDEDASACOMPREHENSIVEREVIEWOFNEUROANATOMY,BUTRATHERASABASISFORUNDERSTANDINGTHEDRUGRELATEDMATERIALTOBEPRESENTEDINLATERCHAPTERSINTHISTEXTADDITIONALINFORMATIONMAYBEOBTAINEDFROMTHEREFERENCESANDSELECTEDREADINGSLISTEDATTHEENDOFTHI

33、SCHAPTERANATOMICALLY,THENERVOUSSYSTEMISDIVIDEDINTOTWOMAJORCOMPONENTSTHECENTRALNERVOUSSYSTEMCNSANDTHEPERIPHERALNERVOUSSYSTEMTHECNS,COMPOSEDOFTHEBRAINANDSPINALCORD,ISRESPONSIBLEFORINTEGRATIVEFUNCTIONSRELATEDTOBOTHCONSCIOUSANDSUBCONSCIOUSACTIVITIESOFTHEBODYITISALSOULTIMATELYRESPONSIBLEFORTHEINTERPRETAT

34、IONOF,ANDREACTIONTO,ALLINFORMATIONTHATTHEBODYRECEIVESFROMTHEENVIRONMENTTHEPERIPHERALNERVOUSSYSTEMISMADEUPOFNERVEFIBERSTHATCONDUCTINFORMATIONTOWARDTHECNSAFFERENTFIBERSANDNERVEFIBERSTHATCONDUCTDIRECTIVESFROMTHECNSTOALLBODYAREASEFFERENTFIBERSBEFOREUNDERTAKINGAGENERALDISCUSSIONOFTHENERVOUSSYSTEM,ABRIEFR

35、EVIEWOFTHEBASICUNITOFTHENERVOUSSYSTEM,THENEURON,ANDTHEMECHANISMSBYWHICHINFORMATIONISTRANSFERREDTHROUGHOUTTHENERVOUSSYSTEMISINORDERTHENEURONTHENEURON,ORNERVECELL,ISTHEBASEOFALLACTIVITIESOFTHENERVOUSSYSTEMNEURONSDIFFERFROMOTHERBODYCELLSINTWORESPECTS1THEYCANCONDUCTINFORMATIONINTHEFORMOFELECTRICALIMPULS

36、ESOVERLONGDISTANCESAND2THEYRELATETOOTHERNERVECELLSANDINNERVATEDTISSUEINAHIGHLYSPECIALIZEDMANNERTHENEURONCONSISTSOFACELLBODY,ANAXON,WHICHCARRIESINFORMATIONAWAYFROMTHECELLBODY,ANDONEORMOREDENDRITES,WHICHCARRYINFORMATIONTOWARDTHECELLBODYSOMEAXONSARESURROUNDEDBYALAYEROFFATTYTISSUECALLEDAMYELINSHEATH,WHI

37、CHDEVELOPSWITHINTHENERVOUSSYSTEMOVERAPERIODOFYEARSANDSERVESASAPROTECTIVECOATINGTHEABILITYOFTHENEURONTOTRANSMITINFORMATIONFROMONESITETOANOTHERISAFUNCTIONOFITSELECTRICALTRANSMISSIONCAPABILITYANDITSCAPACITYTOSYNTHESIZE,STORE,ANDRELEASEHIGHLYSPECIFICCHEMICALSNEUROTRANSMITTERSFROMNERVEENDINGSTHESITEWHERE

38、TWONERVEENDINGSMEETORWHEREANERVEMEETSTHETISSUETHATITINNERVATESISASMALLGAPTHATISTERMEDTHESYNAPSE,ORSYNAPTICCLEFTINORDERFORELECTRICALIMPULSESTOCROSSASYNAPSE,ANEUROTRANSMITTERISRELEASEDFROMONENERVEENDINGTOTRAVELACROSSTHESYNAPSEANDSTIMULATERECEPTORSONANADJACENTNERVEORTISSUETHEPERIPHERALNERVOUSSYSTEMTHEP

39、ERIPHERALNERVOUSSYSTEMCONSISTSOFALLTHENERVEFIBERSTHATCONDUCTINFORMATIONTOANDFROMTHECNSANDTHATLIEOUTSIDETHEBRAINANDSPINALCORDPERIPHERALAFFERENTFIBERSAREINVOLVEDWITHSENSATIONSSUCHASPAIN,TEMPERATURE,ANDTOUCH,WHEREASPERIPHERALEFFERENTFIBERSAREINVOLVEDWITHTHECONTROLOFSPECIFICBODYFUNCTIONSEFFERENTFIBERSAR

40、EDIVIDEDINTOTWOCATEGORIES1SOMATICFIBERS,WHICHCONTROLTHEFUNCTIONOFSKELETALMUSCLE,AND2AUTONOMICFIBERS,WHICHCONTROLTHEACTIVITIESOFSMOOTHMUSCLE,CARDIACMUSCLE,ANDGLANDSOFEXCRETIONSOMATICNERVEFIBERSLEAVETHESPINALCORDATVARIOUSLEVELS,DEPENDINGONTHELOCATIONOFTHEINNERVATEDSKELETALMUSCLE,ANDCONTINUEASANUNINTER

41、RUPTEDUNITFROMTHEIRSITEOFORIGINMOTORNEURONTOSKELETALMUSCLETISSUETHESITEATWHICHTHESOMATICFIBERMEETSTHESKELETALMUSCLEISTERMEDTHENEUROMUSCULARJUNCTIONNMJTHENEUROTRANSMITTERATTHENMJISACETYLCHOLINEAUTONOMICEFFERENTFIBERSCONTROLTHEAUTOMATICORSUBCONSCIOUSFUNCTIONINGOFSMOOTHANDCARDIACMUSCLEANDEXOCRINEGLANDS

42、THESEFIBERSARERESPONSIBLEFORACTIVITIESSUCHASTHEMAINTENANCEOFTONEINTHEGASTROINTESITINALTRACTANDBLOODVESSELS,REGULATIONOFHEARTRATEANDRELEASEOFSUBSTANCESSUCHASSALIVA,RESPIRATORYSECRETIONS,ANDGASTRICACIDAUTONOMICFIBERTRACTSACTUALLYCONSISTOFTWOSEPARATEFIBERSTHEFIRSTFIBERPRESYNAPTICFIBERORIGINATESINSIDETH

43、ESPINALCORDANDTERMINATESATASYNAPSESOMEWHEREINTHEPERIPHERYTHESECONDFIBERPOSTSYNAPTICFIBERORIGINATESATTHESYNAPSEANDTERMINATESATTHEINNERVATEDTISSUEINMOSTINSTANCES,THESYNAPSESOFANUMBEROFFIBERSAREGROUPEDTOGETHERANDTERMEDAGANGLIONINSUCHCASES,THEPRESYNAPTICANDPOSTSYNAPTICFIBERSAREREFERREDTOASPREGANGLIONICA

44、NDPOSTGLANGLIONICFIBERS,RESPECTIVELYTHESITEATWHICHTHEPOSTGANGLIONICFIBERSYNAPSESWITHTHEINNERVATEDTISSUEISTERMEDTHENEUROEFFECTORJUNCTIONNEJAUTONOMICFIBERSARECATEGORIZEDBYTWOMETHODSTHEFIRSTANDOLDERMETHODOFCLASSIFICATIONISBASEDONTHESITESATWHICHPREGANGLIONICFIBERSLEAVETHECNSNERVESTHATEXITFROMTHETHORACIC

45、ANDLUMBARLEVELSOFTHESPINALCORDARETERMEDSYMPATHETIC,WHEREASTHOSETHATEXITFROMTHESACRALLEVELOFTHESPINALCORDANDCRANIUMARETERMEDPARASYMPATHETICTHESECONDMETHODOFCLASSIFICATIONISBASEDONTHENEUROTRANSMITTERRELEASEDATTHENEJBYTHENERVEFIBERNERVESTHATRELEASEACETYLCHOLINEACHARETERMEDCHOLINERGIC,WHEREASTHOSETHATRE

46、LEASENOREPINEPHRINENEARETERMEDADRENERGICINGENERAL,THETERMSYMPATHETICISINTERCHANGEABLEWITHADRENERGICANDTHETERMPARASYMPATHETICISINTERCHANGEABLEWITHCHOLINERGICCHOLINERGICANDADRENERGICAREUSUALLYTHEPREFERREDTERMSWHENDISCUSSINGDRUGEFFECTSONAUTONOMICFUNCTIONBECAUSETHEYDESIGNATETHESPECIFICNEUROTRANSMITTERSA

47、FFECTEDBYTHEDRUGSWITHINTHEAUTONOMICNERVOUSSYSTEMANS,RECEPTORSITESFORACHANDNEHAVEAVERYSPECIFICNOMENCLATUREBASEDUPONTHEIRLOCATIONANDFUNCTIONCHOLINERGICRECEPTORSITESAREFOUNDINTHEGANGLIONICSYNAPSESOFBOTHTHESYMPATHETICANDPARASYMPATHETICNERVOUSSYSTEMTHEYAREALSOFOUNDATTHENEJOFPARASYMPATHETICFIBERSCHOLINERG

48、ICRECEPTORSITESARECATEGORIZEDASBEINGEITHERMUSCARINICORNICOTINIC,BASEDONWHETHERTHEYRESPONDTOTHEALKALOIDSMUSCARINEORNICOTINE,RESPECTIVELYMUSCARINICRECEPTORSAREFOUNDATTHEPARASYMPATHETICNEJNICOTINICRECEPTORSAREFOUNDATALLAUTONOMICGANGLIAANDATTHESOMATICNMJADRENERGICRECEPTORSITESINTHEANSAREFOUNDONLYATTHESY

49、MPATHETICNEJADRENERGICRECEPTORSAREDIVIDEDINTOTHREECATEGORIESALPHA,BETA1,ANDBETA2INGENERAL,STIMULATIONOFTHEALPHAADRENERGICRECEPTORSITECAUSESANINCREASEINACTIVITYOFTHEINNERVATEDTISSUEALPHARECEPTORSAREFOUNDPRIMARILYINARTERIOLESANDTHEREFOREAREIMPORTANTINTHEMAINTENANCEOFBLOODPRESSURESTIMULATIONOFALPHARECEPTORSBYNELEADSTOARTERIOLARCONSTRICTION,WHICHINCREASESBLOODPRESSUREBETA1RECEPTORSAREFOUNDONLYINCARDIACTISSUESTIMULATIONOFTHESERECEPTORSLEA