病理學總論4血液循環(huán)障礙

HemodynamicDisordersContentsHyperemiaandcongestionHemorrhageHemostasisandthrombosisEmbolismInfarctionHyperemia

andCongestionHyperemia

andCongestionHyperemia(充血）

orcongestion（淤血）

referstoexcessamountofbloodwithinanorganorparticulartissueHyperemia

(active

hyperemia)Hyperemia:

Increasedvolumeofbloodinanaffectedtissueresulting

from

an

augmented

arterialinflow

and

normal

venous

outflow

Hyperemia

Causes:(1)Physiological:skeletalmuscleduringexerciseblushing(2)Pathological:inflammationhyperemia(vasoactivesubstances)hyperemiaafterpression.Morphology:Gross:redness(↑oxygenatedblood)LM:arteriolardilatation

InflammatoryhyperemiaHyperemiainPneumoniaHyperemiaInfection(Pneumonia)CongestionAnincreasedcontentofbloodinanorganortissue

resulting

from

diminishedvenousoutflow.Congestion

(passive

hyperemia)CongestionCauses:1.Heartfailure2.Venouscompression3.VenousocclusionCongestionMorphology:Blue-redcolorationinaffectedparts(cyanosisaccumulationdeoxygenatedhemoglobin),Edema.LowinglocaltemperatureCongestionConsequencesofchroniccongestion(1)Parenchymacells:atrophy,degeneration,necrosis(2)Interstitialhyperplasia:fibrosis→cirrhosis(3)Edema(4)HemorrhageCongestionofthelung,Cause:LeftheartfailureReducedleftventricularoutputAllformsofcardiacpensation(myocardialinfarction,rheumaticstenosis)Acutecongestionofthelung,AlveolarcapillaryengorgedwithbloodAlveolarseptaledemaandspacefilledwithfluidMinuteintra-alveolarhemorrhagesNormallungLungcongestionChroniccongestionofthelungMorphology:AlveolarcapillaryengorgedwithbloodParenchymalcellsdegenerationandnecrosisAlveolarseptathickenedandfibrosisMinuteintra-alveolarspaceshemorrhages→redcellbreakdownandphagocytosisoftheredcelldebris→hemosiderinladenmacrophages“Heartfailurecells”Gross:browninduration（browncirrhosis）ChronicpulmonaryCongestionhemosiderinHeartfailurecellsbrowncirrhosisChroniccongestionoftheliverCause:

RightheartfailureobstructionoftheinferiorvenacavaorhepaticveinChroniccongestionoftheliverMorphologyGross:1.Increasedinliversizeandweight2.Capsuletenseandfirminconsistency3.Centralregionsoflobularredandsurroundbyyellowbrownzone---“nutmegliver”（檳榔肝）ChroniccongestionoftheliverMicroscopy:1.Centralvineandhepaticsinusofcentrilobulardistendedwithblood2.Degeneration,atrophy/necrosisoflivercellsinthecentrilobular3.Fattydegenerationofthelivercellsinperipherallobularresultingfromhypoxia4.Fibrosis(cardiaccirrhosis)NormalliverPortaltriadsCentral

veinLiver-ChronicPassiveCongestion“Nutmeg”Liver

CrossSectionofaNutmeg“Nutmeg”LiverHemostasisandThrombosisNormalHemostasisEndotheliumPlateletsCoagulationSystemEndotheliumAnti-thromboticproperties-Anti-platelet-Anti-coagulant-FibrinolyticeffectsProcoagulantproperties-Tissuefactor-vonWillebrandFactor

PlateletsPlateletsarecirculatingcellularelementsandcontaintwospecifictypesofgranules:--alphagranules--deltagranulesPlateletActivationOncontactwithECM,plateletsundergo:(1)Adhesionandshapechange(2)Secretion(releasereaction)(3)AggregationThrombosisThrombosisThrombosisistheprocessofformationofasolidmassofbloodwithinthevascularsystemofthelivingbody.Thesolidmasscalledthrombus.

PathogenesisofthrombosisendothelialinjurystasisorturbulenceofbloodflowbloodhypercoagulabilityEndothelialinjuryCauses:Atherosclerosismyocardialinfarction,ValvediseasesInflammationtraumaToxicProducts(cigarettes,hypercholesterolemia

etc)AbnormalbloodflowStasisofbloodflowTurbulenceofbloodflowHypercoagulabilitySurgeryortraumaInpregnancyandparturitionUseoralcontraception(避孕）pillEndotoxaemiashockSometumorsStepsintheformationathrombus1.Adhesionofplatelettoexposedcollagen2.SecretionofADP&thromboxane3.Plateletaggregation4.ActivationofbloodcoagulationContinueaboveprocess…..White(head)mixed(body)Red(tail)ProcessofthrombosisinvineplatelettrabecularLinesofZahnTypesofThrombiPalethrombus—composedofplateletandfibrin,firmlyattachedtotheplaceoforiginLocation:arteries,cardiacvalvesandtheinitiativepartofvenousthrombusMixedposedofalternatelayersplateletandfibrinandmingledRBCandWBC(linesofZahn)Location:atthemiddlepartofvenousthrombus,Ballthrombusincardiacatrium.TypesofThrombiRedthrombus—formedinthedownstreamblood(clot),coagulatedredbloodcells.Location:attheendpartofvenousthrombusHyalinethrombus(Microthrombus)posedoffibrinLocation:microcirculationindisseminatedintravascularcoagulation(DIC)Thrombosisoffemoralvein（股靜脈）ThrombusOthertypesofThrombiMuralThrombus(附壁血栓）---anon-occlusivethrombusadheredtothewalloflargebloodvesselorcardiacchamberVegetationthrombi(贅生物血栓）---builtuponvalveoftheheart(infectiousendocarditis,rheumaticendocarditis)MuralThrombus-CardiacMuralThrombiNoticeunderlyingendocardialfibrosisRightLeftVegetationthrombiFateoftheThrombusThrombusDissolutionOrganizationEmbolizationRecanalizationCalcification

(Phlebolith）

PropagationandobstructionThrombusPropagatedintotheInferiorVenaCavaEffectsofthrombosisOcclusion（閉塞）EmbolismDisfigurationofcardiacvalveDICPost-mortemclot&ThrombusAthrombusisdifferentfromaclot!Aclotisdefinedasbloodcoagulatedoutsidethevascularsystemorwithinthevasculeasystemafterdeath.Post-mortemclot&ThrombusPost-mortemclotThrombusNotattachedtothewallGelatinousclot,softWithyellow“chickenfat”supernatantApointattachedtothewallFirmerandfragileStrandsofpalegrayfibrinEmbolismandInfarctionEmbolismandinfarctionaremajorcausesofmorbidityandmortality!MyocardialinfarctionCerebralinfarction(stroke)PulmonaryembolismEmbolism:Embolism:is

a

partial

or

complete

obstruction

of

some

part

of

the

vascular

system

by

any

mass

carried

in

the

circulation,the

transported

material

is

called

embolus.Types

of

embolus1.Thrombi

(

99%)

2.Gas3.Fat4.Tumorfragments5.Amniotic

fluid6.Miscellaneous:

atheroscleroticdebris(cholesterolemboli,foreign

bodies,

parasites

and

etc.)PathwayofembolitravelArterialemboli---systemiccirculationVenousemboli---pulmonarycirculationPortalemboli---liverTypesofembolismThromboembolismCommonesttypeofembolismTheemboluscomefromthelegorpelvicveinorcardiac--Pulmonaryembolism--SystemicembolismPulmonaryThromboembolismPulmonaryemboliareamajorcauseofdeathandmorbidity.Theyaccountforapproximately10%ofdeathsofhospitalizedpatients.

Largemajorityofpulmonaryembolicomefromthedeeplegveinsorpelvicveins.PulmonaryThromboembolismThepossibleresultsare:a.Suddendeath:acuterightventricularfailure.b.Ischemicnecrosisoflungtissue:infarction.c.Multipleemboliovertimemaycausepulmonaryhypertension（肺靜脈高壓）

withrightheartfailured.ClinicalsilentPulmonaryEmbolusSaddlePulmonaryEmbolusSystemicEmbolismEmbolitravelingwithinthearterialcirculation80%arisefromintracardiacmuralthrombioronatheromatousplaqueInfarctionofmajororgans,e.g.brain,kidney,spleenGangreneoftheintestineorlimbsFatembolismCauses:a.Fractureoflongbonesb.Operativemanipulationoffracturesc.TraumatoadiposetissueorfattyliverFatembolismsyndromePulmonaryinsufficiencyneurologicalsymptomsAnemiathrombocytopenia（血小板減少）AirembolismCauses:a.Mismanagedintravenousinfusionsb.Operationsinwhichlargeveinsareopenedc.pressionsickness(減壓?。?gaseousbubblesformingasaconsequenceofrapidlypression.AirembolismGasbubbleswithinthecirculationcanobstructvascularflowtocausedistalischemicinjuryLargeamountsofgasintheheartrenderpumpingineffective--itmerelycompressesthegas.Thefewbubblesintroducedintothebloodduringintravenoustherapyseemtobeharmless.AmnioticfluidembolismAmnioticfluidmaybedriventhroughtheplacentalbed(Ruptureofuterineveins)intothematernalcirculation,whichmayresultacuterespiratorydistressandshock.AmnioticFluidEmbolismSquamouscellsandotherdebrisbefoundinthepulmonaryvasculature.Pulmonaryedema,diffusealveolardamageSmallpulmonarycapillaryembolismDICAmnioticFluidEmbolismPresentwithdyspnea,cyanosis,shock,comaandhemorrhageMortalityof80%Keratinocyte,squamouscellsmucousvernixcaseosameconiumInfarctInfarctionInfarctis

ischemicnecrosis

of

tissue

ororganwithinthelivingbody(85-90%ofallinfarctsduetoarterialthromboticorembolicevents)InfarctionInfarctsaremainlycausedbyinterruptionofthearterialbloodflowbuttheycanbeproducedbyvenousobstructionaswell.Suchasstrangulatedhernias,torsionofthetestis.InfarctCauses:(1)Thrombosis(2)Arterialembolism(3)Bloodvesseliscompressedortwisted(4)SpasmofarteriesFactsinfluencedevelopmentofaninfarct(1)Thenatureofthevascularsupply(2)Therateofdevelopmentoftheocclusion(3)Thevulnerabilityofthetissuetohypoxia(4)OxygencontentofbloodTypes

of

infarctWhiteinfarct

(anemic

infarct)Redinfarct(hemorrhagicinfarct)Septicinfarct—presenceofmicrobialinfectionBlandinfarct—withoutmicrobialinfectionWhiteinfarct

Theresultofarterialo