Unit5Canada-＂TheTrueNorth＂全國優(yōu)質(zhì)課一等獎

TheheartBeforeyoureadWhatdoyouknowabouttheheart?Howdoesitwork?Canyouguesshowmanytimesaheartbeatsinanaveragelifetime?Theanswerisinthepassagebelow.Reading(1)TheheartTheheartisthesymbolofemotionssuchasgratitude,love,hatred,courageandfear.Peoplemaybedescribedasgiving"heartfelt"thanks,lovingwith"alltheirheart",havinga"blackheart",being"bravehearted"orbeing"fainthearted".Inreality,theheartisalife-givingpump,amusclethatisessentialforprovidingthebodywiththepowerthatitneedstofunction.Itcontinuestoworkceaselesslyuntildeath.Yourheartisasmallpump,aboutthesamesizeasyourfist.Itismadeupoffourchambers:thetwoatthetoparecalledtheatria,whilethetwoonthebottomaretheventricles.Theheartallowsthesechamberstofillwithbloodandthenitpumpsthebloodaroundthebody.Theheartisconnectedtoanelaboratesystemofbloodvessels.Themainarteryiscalledtheaorta,whichisjoinedtothetopoftheheartandservestotakethebloodawayfromtheatria.Twolargeveins,knownasthesuperiorvenacavaandtheinferiorvenacava,carrybloodtotheheart.Thepumpingactionisproducedbyamuscleintheheart,calledthecardiacmuscle.Aheartbeatisacontractionofthismuscleasitforcesbloodthroughthechambersoftheheartandintotheaorta.Theheartperformsthispumpingactionmorethantwoandahalfbilliontimesinanaverageperson'slifetime,beatingataround70beatsaminute.Vigorousexercise,suchasrunning,putsmoredemandsonyourheart.Yourbodyneedsmoreenergyfromblood,sotheheartneedstopumpfaster.Whenyourelax,orsleep,theheartisabletoslowdown.Becauseofitsimportance,theheartisverycarefullylocatedinthebody.Itisshieldedbythestrongbreastboneandtheribcage,andprotectedbelowbythepowerfulmusclesofthediaphragm.Thisprotectionmakesitdifficultfordoctorstomonitoritscondition.Specialtechniques,suchasx-rayscanning,havebeendevelopedtochecktheperformanceofthemuscle.Thecommonestheartproblemsarearrhythmia(心律不齊),whichisanirregularheartbeatpattern,andamurmur(雜音),whichoccurswhenthewallsbetweenthechambersoftheheartareveryweak,allowingbloodtopassthroughfromonechambertothenext.Thebestwaytokeepyourheartingoodshapeistotakeplentyofexerciseandtoeathealthyfood.(403words/_____minutes)Vocabularyemotion情感g(shù)ratitude感激之情heartfelt衷心的，誠摯的fainthearted膽怯的；無決斷的chamber室，腔atria心房ventricle心室elaborate精巧的；復(fù)雜的vessel血管；脈管artery動脈aorta王動脈vein靜脈superiorvenacava上腔靜脈inferiorvenacava下腔靜脈cardiac心臟的muscle肌；肌肉heartbeat心搏；心跳聲contraction收縮vigorous強(qiáng)勁的；有力的shield保護(hù)breastbone胸骨ribcage胸腔diaphragm膈；隔膜NoteManyEnglishwordsinbiology,suchasatria,aortaandvenacava,aretakenfromtheLatinlanguage(拉丁文).Exercise1Answerthesequestions.1.Howmanychambersarethereinaheart?2.Howbigisyourheart?3.Howmanyveinscarrybloodtotheheart?4.Howmanytimesdoesaheartbeatinaminute?5.Whydoesyourheartbeatfasterwhenyoudovigorousexercise?Exercise2Matchthewordsandthedescriptions.WordDescription1.aorta2.atria3.ventricles4.inferiorvenacava5.arrhythmia6.murmurAirregularheartbeatBthelowerchambersoftheheartCthearterythattakesbloodfromtheheartDaveinthatbringsbloodtotheheartEbloodpassingthroughaweakheartwallFtheupperchambersoftheheartReading(2)AhearttransplantIfaperson'sheartisbadlydiseasedandheartsurgerycannotrepairthedamage,atransplantmaybenecessary.Atransplantinvolvestakingthehealthyheartofsomeonewhohasrecentlydied,andplacingitinthepatientasareplacementforthediseasedheart.Duringtheoperation,thepatientisattachedtoaheart/lungmachine.Thismachineactsinsteadoftheheartinpumpingbloodaroundthebody.Next,surgeonsremovethediseasedheart,leavingjustthebackwallsoftheatria.Thenewheartissewntothesewalls,onceitsownbackwallshavebeenremoved.Thenextphaseistogetthenewheartworking.Thebloodvesselsareattachedand,asbloodstartsflowing,theheartstartstobeatregularly.Iftherearenoproblems,thesurgeonswillremovethepatientfromtheheart/lungmachineandclosethechest.Thewholeoperationtakesaboutsixhours.(156words/________minutes)Vocabularysurgery手術(shù)transplant移植diseased有病的；不健全的replacement代替；更換；替補(bǔ)attach連接remove去掉；切除phase階段Exercise3Numbertheseactionsintothecorrectorder.StepsinahearttransplantThenewheartisattachedtotheoldbackwallsoftheatria.Thesurgeonsclosethepatient'schest.Thepatientisattachedtoaheart/lungmachine.Thediseasedheartisremovedfromthepatient.Thenewheartstartsbeating.Thehealthyheartisremovedfromadeadbody.Thebloodvesselsareconnectedtothenewheart.____________________________________________________________________________________Exercise4Herearesomeinterestingfactsabouttheheart.Findoutsomemoreandaddthemtothelist.Heartfacts●Theaortamthelargestarteryinthebody--isasthickasyourthumb.●Youhaveaboutlitresofblood,whichcirculatesthroughyourbodythreetimeseveryminute.●Inanaveragelifetime,theheartpumpsImillionbarrelsofbloodthroughthebody.