Week 3 Quiz 1 Thrombosis I-IL.Hemodynamics.Atherosclerosis 1.A 25-year-old female medical student is found to be anemic on a routine physical.She reports heavy menstrual bleeding throughout her life.She has also experienced frequent epistaxis(nose bleeds)and a "funny rash"on her legs whenever she takes aspirin.Her aPTT was also found to be mildly prolonged.Which diagnosis is most likely? A Factor vIll deficiency R Glanzma ann thrombasthenia C Live D.Th ombin defici E.VonWil ebrand Ans:E Von Willebrand disease results in both a platelet defect (prolonged bleeding time and micro- hemorrhages)AND a coagulation defect (prolonged PTT).Factor VIll deficiency (type A hemophilia)is X-linked (therefore more common in males)and would likely present with macro- hemorrhages,hemarthroses.and a prolonged PTT,but not a rash or menorrhagia.Glan-mann thrombasthenia is a platelet disorder due to defective plug formation (decreased Gpllb/Illa)that would not prolong the PTT.Liver failure would reduce the production of clotting factors,but this diagnosis is unlikely given only mild coagulation and platelet disturbances.Thrombin (factor lla)would present with prolonged PT,not PTT. 2.While shaving one morning L a 23-vear-old man nicks his lip with a razor.Seconds after the injury,the bleeding stops.Which of the following mechanisms is most likely to reduce blood loss from a small dermal vein? ization C Plat activation Ans:C The first barrier to further bleeding is the formation ofa platelet plug.This structure is very fragile,but gets reinforced by cross-linking with fibrinogen which is transformed to fibrin. Fibrin cross-linking is critical to reinforcing the platelet plug.but alone is not sufficient to stop bleeding.Neutrophil chemotaxis will clear bacteria introduced into the wound,but these cells do not stop bleeding.Protein C activation promotes anticoagulation,serving as a check on the coagulation cascade,which is the opposite of the desired effect for this patient.Vasodilation occurs in the setting of injury and inflammation,but this does not reduce blood loss.Week 3 Quiz 1 Thrombosis I-II, Hemodynamics, Atherosclerosis 1. A 25-year-old female medical student is found to be anemic on a routine physical. She reports heavy menstrual bleeding throughout her life. She has also experienced frequent epistaxis (nose bleeds) and a "funny rash" on her legs whenever she takes aspirin. Her aPTT was also found to be mildly prolonged. Which diagnosis is most likely? A. Factor VIII deficiency B. Glanzmann thrombasthenia C. Liver failure D. Thrombin deficiency E. VonWillebrand disease Ans: E Von Willebrand disease results in both a platelet defect (prolonged bleeding time and micro￾hemorrhages) AND a coagulation defect (prolonged PTT). Factor VIII deficiency (type A hemophilia) is X-linked (therefore more common in males) and would likely present with macro￾hemorrhages, hemarthroses, and a prolonged PTT, but not a rash or menorrhagia. Glanzmann thrombasthenia is a platelet disorder due to defective plug formation (decreased GpIIb/IIIa) that would not prolong the PTT. Liver failure would reduce the production of clotting factors, but this diagnosis is unlikely given only mild coagulation and platelet disturbances. Thrombin (factor IIa) would present with prolonged PT, not PTT. 2. While shaving one morning, a 23-year-old man nicks his lip with a razor. Seconds after the injury, the bleeding stops. Which of the following mechanisms is most likely to reduce blood loss from a small dermal vein? A. Fibrin polymerization B. Neutrophil chemotaxis C. Platelet aggregation D. Protein C activation E. Vasodilation Ans: C The first barrier to further bleeding is the formation of a platelet plug. This structure is very fragile, but gets reinforced by cross-linking with fibrinogen which is transformed to fibrin. Fibrin cross-linking is critical to reinforcing the platelet plug, but alone is not sufficient to stop bleeding. Neutrophil chemotaxis will clear bacteria introduced into the wound, but these cells do not stop bleeding. Protein C activation promotes anticoagulation, serving as a check on the coagulation cascade, which is the opposite of the desired effect for this patient. Vasodilation occurs in the setting of injury and inflammation, but this does not reduce blood loss