plasma | Definition, Function, & Composition | Britannica

plasma, also called blood plasma, the liquid portion of blood. Plasma serves as a transport medium for delivering nutrients to the cells of the various ... plasma Sections&Media Article Introduction&QuickFacts FastFacts 2-MinSummary Facts&RelatedContent Media Videos Images AdditionalInfo MoreArticlesOnThisTopic Contributors ArticleHistory Home Health&Medicine Anatomy&Physiology plasma biology Alternatetitles:bloodplasma Print Cite verifiedCite Whileeveryefforthasbeenmadetofollowcitationstylerules,theremaybesomediscrepancies. Pleaserefertotheappropriatestylemanualorothersourcesifyouhaveanyquestions. SelectCitationStyle MLA APA ChicagoManualofStyle CopyCitation Share Share Sharetosocialmedia Facebook Twitter URL https://www.britannica.com/science/plasma-biology More GiveFeedback ExternalWebsites Feedback Corrections?Updates?Omissions?Letusknowifyouhavesuggestionstoimprovethisarticle(requireslogin). 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By DavidH.Yawn | ViewEditHistory FastFacts 2-MinSummary Facts&RelatedContent bloodplasma Seeallmedia KeyPeople: EdwinJosephCohn ...(Showmore) RelatedTopics: complement serumalbumin transferrin serum chylomicron ...(Showmore) Seeallfactsanddata→ plasma,alsocalledbloodplasma,theliquidportionofblood.Plasmaservesasatransportmediumfordeliveringnutrientstothecellsofthevariousorgansofthebodyandfortransportingwasteproductsderivedfromcellularmetabolismtothekidneys,liver,andlungsforexcretion.Itisalsoatransportsystemforbloodcells,anditplaysacriticalroleinmaintainingnormalbloodpressure.Plasmahelpstodistributeheatthroughoutthebodyandtomaintainhomeostasis,orbiologicalstability,includingacid-basebalanceinthebloodandbody.Plasmaisderivedwhenallthebloodcells—redbloodcells(erythrocytes),whitebloodcells(leukocytes),andplatelets(thrombocytes)—areseparatedfromwholeblood.Theremainingstraw-colouredfluidis90–92percentwater,butitcontainscriticalsolutesnecessaryforsustaininghealthandlife.Importantconstituentsincludeelectrolytessuchassodium,potassium,chloride,bicarbonate,magnesium,andcalcium.Inaddition,therearetraceamountsofothersubstances,includingaminoacids,vitamins,organicacids,pigments,andenzymes.Hormonessuchasinsulin,corticosteroids,andthyroxinearesecretedintothebloodbytheendocrinesystem.Plasmaconcentrationsofhormonesmustbecarefullyregulatedforgoodhealth.Nitrogenouswastes(e.g.,ureaandcreatinine)transportedtothekidneyforexcretionincreasemarkedlywithrenalfailure.bloodcomponentsdiagramBloodismadeupofmultiplecomponents,includingredbloodcells,whitebloodcells,platelets,andplasma.EncyclopædiaBritannica,Inc. ReadMoreonThisTopic blood:Plasma Theliquidportionoftheblood,theplasma,isacomplexsolutioncontainingmorethan90percentwater.Thewaterof... LearnhowscientistsusedafidgetspinnertoseparateplasmafrombloodcellsResearchersuseafidgetspinnerasacentrifugetoseparatebloodplasma.©AmericanChemicalSociety(ABritannicaPublishingPartner)SeeallvideosforthisarticlePlasmacontains6–8percentproteins.Onecriticalgroupisthecoagulationproteinsandtheirinhibitors,synthesizedprimarilyintheliver.Whenbloodclottingisactivated,fibrinogencirculatinginthebloodisconvertedtofibrin,whichinturnhelpstoformastablebloodclotatthesiteofvasculardisruption.Coagulationinhibitorproteinshelptopreventabnormalcoagulation(hypercoagulability)andtoresolveclotsaftertheyareformed.Whenplasmaisallowedtoclot,fibrinogenconvertstofibrin,trappingthecellularelementsofblood.Theresultingliquid,devoidofcellsandfibrinogen,iscalledserum.Biochemicaltestingofplasmaandserumisanimportantpartofmodernclinicaldiagnosisandtreatmentmonitoring.Highorlowconcentrationsofglucoseintheplasmaorserumhelptoconfirmseriousdisorderssuchasdiabetesmellitusandhypoglycemia.Substancessecretedintotheplasmabycancersmayindicateanoccultmalignancy;forinstance,anincreasedconcentrationofprostate-specificantigen(PSA)inamiddle-agedasymptomaticmanmayindicateundiagnosedprostatecancer.Serumalbumin,anotherproteinsynthesizedbytheliver,constitutesapproximately60percentofalloftheplasmaproteins.Itisveryimportantinmaintainingosmoticpressureinthebloodvessels;itisalsoanimportantcarrierproteinforanumberofsubstances,includinghormones.Otherproteinscalledalphaandbetaglobulinstransportlipidssuchascholesterolaswellassteroidhormones,sugar,andiron. GetaBritannicaPremiumsubscriptionandgainaccesstoexclusivecontent. SubscribeNow Thegammaglobulins,orimmunoglobulins,areanimportantclassofproteinsthataresecretedbyBlymphocytesoftheimmunesystem.Theyincludemostofthebody’ssupplyofprotectiveantibodiesproducedinresponsetospecificviralorbacterialantigens.Cytokinesareproteinssynthesizedbycellsofvariousorgansandbycellsfoundintheimmunesystemandbonemarrowinordertomaintainnormalbloodcellformation(hematopoiesis)andregulateinflammation.Forexample,onecytokinecallederythropoietin,synthesizedbyspecializedkidneycells,stimulatesbonemarrowbloodprogenitorcellstoproduceredbloodcells.Othercytokinesstimulatetheproductionofwhitebloodcellsandplatelets.Anotherproteinsystemintheplasma,calledcomplement,isimportantinmediatingappropriateimmuneandinflammatoryresponsestoavarietyofinfectiousagents.Theelectrolytesandacid-basesystemfoundintheplasmaarefinelyregulated.Forexample,potassiumisnormallypresentinplasmainaconcentrationofonly4milliequivalentsperlitre.Aslightriseinplasmapotassium(to6–7milliequivalentsperlitre)canresultindeath.Likewise,sodium,chloride,bicarbonate,calcium,andmagnesiumlevelsintheplasmamustbepreciselymaintainedwithinanarrowrange.Smallermoleculessuchassodium,potassium,glucose,andcalciumareprimarilyresponsiblefortheconcentrationofdissolvedparticlesintheplasma.However,itistheconcentrationofmuchlargerproteins(especiallyalbumin)oneithersideofsemipermeablemembranessuchastheendothelialcellsliningthecapillariesthatcreatescrucialpressuregradientsnecessarytomaintainthecorrectamountofwaterwithintheintravascularcompartmentand,therefore,toregulatethevolumeofcirculatingblood.So,forexample,patientswhohavekidneydysfunctionorlowplasmaproteinconcentrations(especiallylowalbumin)maydevelopamigrationofwaterfromthevascularspaceintothetissuespaces,causingedema(swelling)andcongestionintheextremitiesandvitalorgans,includingthelungs.DavidH.Yawn LearnMoreintheserelatedBritannicaarticles: blood:Plasma Theliquidportionoftheblood,theplasma,isacomplexsolutioncontainingmorethan90percentwater.Thewateroftheplasmaisfreelyexchangeablewiththatofbodycellsandotherextracellularfluidsandisavailabletomaintainthenormalstateof… therapeutics:Plasma Plasma,theliquidportionoftheblood,ismorethan90percentwater.Itcontainsallthenoncellularcomponentsofwholebloodincludingthecoagulationfactors,immunoglobulinsandotherproteins,andelectrolytes.Whenfrozen,thecoagulationfactorsremainstableforuptooneyear… protein:Fibrinogenandfibrin …calledbloodserum,isbloodplasmaminusfibrinogen.Thefibrinogencontentofthebloodplasmais0.2to0.4percent.… Historyatyourfingertips SignupheretoseewhathappenedOnThisDay,everydayinyourinbox! 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