瘀斑现象,近一个月来多次发生鼻出血,双亲为近亲婚配,家系中均无类似出血情况。实验室检查发现,外周血血小板计数正常,出血时间延长,凝血时间正常,血小板膜表面糖蛋白IIb显著降低,基因诊断证实糖蛋白IIb(GPIIb)基因错义突变。该患儿出血时间延长与血小板的那项功能有关:
A. 释放能力降低
B. 收缩能力降低
C. 黏附能力降低
D. 聚集能力降低
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A65-year-oldslightlycyanoticmanpresentstohisphysiciancomplainingofruritusandnosebleeds.Abloodtestrevealsahematocritof62%,leadingtothediagnosisofpolycythemiavera.Treatmentincludesaspirintopreventthrombosisandperiodicphlebotomytoreducethehematocrit.Thereductioninhematocritisbeneficialbecauseitdoeswhichofthefollowing?
A. Reducesbloodvelocity
B. Decreasescardiacoutput
C. Reducesbloodviscosity
D. Increasesarterialoxygensaturation
A35-year-oldwomanpresentstoherfamilyphysician’sofficewithfatigueofatleast3months’duration.Heronlyexplanationisthatkeepingupwithhertwin4-year-oldsreallytiresherout,andshedoesnotevenhaveenoughenergytomakenutritiousmealsforherandherhusband.VitalsignsandECGarenormal,butathirdheartsoundisheardwithauscultationandsheispale.Bloodresultsareasfollows:Hb,8g/dL;hematocrit,30%;MCV,115fL;WBC,8000/μL;platelets,200,000/μL.Adeficiencyofwhichofthefollowingsubstancescanmostlikelyaccountforthesefindings?
A. Folate
B. Glucose-6-phosphatase
C. Niacin
D. Iron
A67-year-oldwomanwithahistoryofvenousthromboembolismisplacedonwarfarin(Coumadin;Bristol-MyersSquibbCompany,NewYork,NYUSA)prophylactically.ThebloodconcentrationofCoumadinbecomestoohighandbleedingoccurs.Thebleedingcanbestbetreatedbytheadministrationofwhichofthefollowing?
A. Platelets
B. Thrombin
C. VitaminK
D. Fibrinogen
外源性凝血途径的始动因子是
A. FⅡ
B. FⅦ
C. FⅢ
D. FⅠ