Physiology Flashcards
What is a deficiency in GpIb called?
Bernard-Soulier syndrome
What is a deficiency in vWF called?
von Willebrand disease
Failure of aggregation with ristocetin assay occurs in what diseases?
von Willebrand disease and Bernard-Soulier syndrome
What activates vWF to bind GpIb
Ristocetin
What drugs inhibit GpIIb/IIIa directly
Tirofiban, Eptifibatide, Abciximab (TEA)
What drugs inhibit ADP-induced expression of GpIIb/IIIa via P2Y12 receptor?
Prasugrel, Clopidogrel, Ticlopidine (PCT)
What drug inhibits TXA2 synthesis?
Aspirin
What are the steps of primary hemostasis?
Injury, exposure, adhesion, activation, aggregation
What anti-aggregation factor is released by endothelial cells?
Nitrous oxide (NO)
What are the anti-aggregation factors?
PGI2 and NO, increased blood flow, and decreased platelet aggregation
What are the pro-aggregation factors?
TXA2, decreased blood flow, increased platelet aggregation
What binds GpIIb/IIIa allowing linking of platelets?
Fibrinogen
What induces GpIIb/IIIa expression at platelet surface?
ADP binding to P2Y12 receptor
What helps platelets adhere to endothelium?
ADP
What mediates vasoconstriction in a damaged endothelial cell?
Endothelin and neural stimulation reflex
What is released from damaged endothelial cell that causes vasoconstriction?
Endothelin
What initiates platelet plug formation?
Endothelial cell injury
What causes a conformational change in platelets to release ADP, calcium and TXA2?
Binding of GpIb to vWF
What does vWF bind to on the platelet?
GpIb
What does vWF bind to on the endothelial cell?
Exposed collagen
What is used clinically as a thrombolytic?
tPA
What is the function of Protein C and S?
Cleave factors Va and VIIa
What is factor V Leiden?
Factor V resistant to protein C
What are the principle targets of antithrombin?
Factors Xa and thrombin (IIa)
What does heparin enhance the activity of?
Antithrombin
What factors are inhibited by antithrombin?
Activated factors II, VII, IX, X, XI, XII
What enzyme converts factors II, VII, IX, X, proteins C and S into their active forms?
y-glutamyl carboxylase
What enzyme reduces vitamin K?
Epoxide reductase
What factor carries or protects factor VIII
vWF
What coagulation factors will be low in vitamin K deficiency?
Factors II, VII, IX, X, protein C and S
What inhibits vitamin K and its enzyme, epoxide reductase?
Warfarin
What is the inheritance pattern of hemophilia C?
Autosomal recessive
What is the inheritance pattern of hemophilia A and B?
X-linked recessive
What is a deficiency in factor XI called?
Hemophilia C
What is a deficiency in factor IX called?
Hemophilia B
What is a deficiency in factor VIII called?
Hemophilia A
What is the function of plasmin?
Degrade the fibrin mesh and destroy coagulation factors
What is the action of thrombolytics like alteplase, reteplase, streptokinase, and tenecteplase?
Promotes conversion of plasminogen to plasmin
Which coagulation factors are part of the common pathway?
Factors I, II, V, X
Which coagulation factors are part of the intrinsic pathway?
Factors XII, XI, IX, VIII
Which coagulation factors are part of the extrinsic pathway?
Factor VII
What inactivates bradykinin?
ACE
What activates bradykinin?
Kallikrein
What converts plasminogen to plasmin?
tPA
Aminocaproic acid targets what part of the coagulation pathway?
tPA (fibrinolytic system)
What is the target of Fondaparinux?
Factor Xa in the common pathway
Apixaban and rivaroxaban target which part of the coagulation pathway?
Common pathway (Xa)
Which anticoagulant has the greatest efficacy on factor Xa?
LMWH
What is the function of bradykinin in the coagulation cascade?
Increase pain, permeability and vasodilation
Why does the HbS molecule not migrate as far as an HbA molecule on gel electrophoresis?
The negative glutamic acid is replaced by neutral valine
Why does the HbC molecule migrate the least on gel electrophoresis?
The negative glutamic acid is replaced by positive lysine
On a gel electrophoresis, which Hb molecule migrates the least?
HbC
On a gel electrophoresis, which Hb molecule migrates the furthest?
HbA
On a gel electrophoresis, in which direction does Hb migrate?
Negative cathode to positive anode
What is the presentation of ABO hemolytic disease of the newborn?
Mild jaundice within 24 hours of birth
What is the treatment for ABO hemolytic disease of the newborn?
Phototherapy or exchange transfusion
Who is usually susceptible to ABO hemolytic disease of the newborn?
Type A or B fetuses born to type O mothers
What type of immunoglobulin is anti-D seen in Rh negative mothers?
IgG
Rh type considered universal recipient of RBCs
Rh positive
What type of immunoglobulins are anti-B and anti-A?
IgM
Why are O blood types considered universal recipients of plasma?
They have both anti-A and anti-B
Blood type considered universal recipient of plasma
O
Why are O blood types considered universal donors of RBCs?
They do not express any A or B receptors
Blood type that is the universal donor of RBCs
O
Why are AB blood types considered universal donors of plasma?
Their plasma does not contain any anti-A or anti-B antibodies
Why are AB blood types considered universal recipients of RBCs?
They have receptors for both A and B blood
Blood type that is the universal recipient of RBCs
AB
Blood type that is the universal donor of plasma
AB
When is RhoGAM given?
3rd trimester and early postpartum period
Who is given RhoGAM?
Rh negative mothers with an Rh positive fetus
When do Rh negative mothers develop anti-D IgG antibodies?
If exposed to Rh positive blood
What chains make up HbA2?
2-alpha and 2-delta chains
Small form of adult hemoglobin present in small amounts?
HbA2
Chains that make up adult Hb?
2-alpha and 2-beta
Chains that make up fetal Hb?
2-alpha and 2-gamma chains
Chains that make up embryonic Hb?
2-zeta and 2-epsilon chains
Site of fetal erythropoiesis which occurs in 18 weeks to adult and lifelong
Bone marrow
Site of fetal erythropoiesis which occurs in 10-28 weeks
Spleen
Site of fetal erythropoiesis which occurs in 6 weeks to birth
Liver
Site of fetal erythropoiesis which occurs in 3-8 weeks
Yolk sac
