blood pressure annajah national university血压纳贾赫国立大学.ppt

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1、BloodPressureArterialbloodpressureisameasureofthepressureexertedbythebloodasitflowsthroughthearteries.Thesystolicpressureisthepressureofthebloodasaresultofcontractionoftheventricles.Diastolicpressure:isthepressurewhentheventriclesareatrest.Diastolicpressure:isthelowerpressur

2、epresentatalltimeswithinthearteries.Pulsepressure:thedifferencesbetweenthetwocalledtheDeterminantsofbloodpressurePumpingactionoftheheart:whenitisweak,lessbloodispumpedintoarteries"lowercardiacoutput",andthebloodpressuredecreases.Peripheralvascularresistance:canincreasebloodp

3、ressureespeciallythediastolicpressure.Somefactorsthatcreateresistanceinthearterialsystemarethecapacityofthearteriolesandthecapillaries,thecomplianceofthearteries,andtheviscosityofthebloodDeterminantsofbloodpressureBloodvolume;whenthebloodvolumedecreasesasaresultofhemorrhage,

4、thebloodpressuredecreasesbecauseofthedecreasedfluidinthearteries.Bloodviscosity;bloodpressureishigherwhenthebloodishighlyviscous"thick"thatis,whentheproportionofRBCtothebloodplasmaishigh.FactorsaffectingBloodPressureAge;thepressureriseswithage,reachingapeakattheonsetofpubert

5、y,andthentendtodecline.Exercise;physicalactivityincreasesthecardiacoutputandhenceinbloodpressure;thus20-30minutesofrestfollowingexerciseisindicatedbeforetherestingbloodpressurecanreliablyassessed.Stress;stimulationofthenervoussystemincreasescardiacoutputandvasoconstrictionof

6、thearterioles,howeverseverepaincandecreasebloodpressuregreatlybyinhibitingthevasomotorcenterandprovidevasodilatationFactorsaffectingBloodPressureRace(AfricanAmericanmalesover35yearshavehigherBPthanEuropeanAmericanmales)Gender;afterpuberty,femaleusuallyhavelowerbloodpressuret

7、hanmalesatthesameage.AftermenopausethefemalehashigherbloodpressurethanmalesMedicationsObesity;predisposetohighbloodpressureFactorsaffectingBloodPressureDiurnalvariations;pressureisusuallylowestearlyinthemorningwhenmetabolicrateislow.Diseaseprocess;anyconditionaffectingthecar

8、diacoutput,bloodvolume,bloodviscosity,andcomplianceofthearterieshasadirecte