Deck 14: Alterations in Hemostasis and Blood Coagulation

Question 1

A prolonged bleeding time (more than 10 minutes) in association with normal platelet count, normal prothrombin time (PT), and activated partial thromboplastin time (aPTT) is indicative of

A) vitamin K deficiency.
B) hemophilia B.
C) hemophilia A.
D) platelet dysfunction.

Answer 1

platelet dysfunction.

Question 2

The megakaryocyte is a precursor to

A) factor IX.
B) white blood cells.
C) red blood cells.
D) platelets.

Answer 2

platelets.

Question 3

The activated partial thromboplastin time (aPTT) is used to evaluate the extrinsic pathway of the coagulation cascade.

Answer 3

False

Question 4

Factor VII is an extrinsic pathway factor whose synthesis is not vitamin K dependent.

Question 5

The final step in clot formation is

A) conversion of prothrombin to thrombin.
B) platelet degranulation and adhesion.
C) conversion of fibrinogen to fibrin.
D) conversion of plasminogen to plasmin.

Question 6

The prothrombin time (PT) and INR (International Normalized Ratio) measure the integrity of

A) platelet function.
B) extrinsic and common pathway.
C) intrinsic pathway.
D) common pathway only.

Question 7

A commonly ingested substance associated with prolongation of the bleeding time is

A) acetaminophen.
B) tobacco.
C) caffeine.
D) aspirin.

Question 8

Plasmin degrades fibrin clots.

Question 9

The conversion of plasminogen to plasmin results in

A) clot retraction.
B) fibrinolysis.
C) platelet aggregation.
D) activation of thrombin.

Question 10

Causes of thrombocytopenia include

A) hypoxemia.
B) reduced erythropoietin.
C) chemotherapy.
D) secondary polycythemia.

Question 11

Platelets stick to each other by binding fibrinogen with their integrin receptors.

Question 12

Dysfunction of which of the following organs would lead to clotting factor deficiency?

A) Liver
B) Kidney
C) Spleen
D) Pancreas

Question 13

Thromboxane A₂ is a potent platelet activator whose production is blocked by aspirin.

Question 14

The activated partial thromboplastin time (aPTT) is a measure of the integrity of

A) the extrinsic pathway.
B) the intrinsic pathway.
C) factor VIII synthesis.
D) plasminogen.

Question 15

Platelets are cell fragments that contain no internal organelles.

Question 16

Fibrinogen is a factor in the final common pathway of the coagulation cascade.

Question 17

An elevated international normalized ratio (INR) indicates excessive activation of the coagulation cascade.

Question 18

Activation of the extrinsic pathway of coagulation is initiated by

A) platelet factors.
B) collagen exposure.
C) tissue thromboplastin.
D) factor VIII.

Question 19

A normal platelet count is between 25,000 and 100,000 platelets per microliter of blood.

Question 20

Antithrombin III is a coagulation factor that activates prothrombin to form thrombin.

Question 21

Widespread activation of the clotting cascade secondary to sepsis or massive trauma is called

A) hemophilia B.
B) disseminated intravascular coagulation (DIC).
C) Hageman disease.
D) idiopathic thrombocytopenia purpura.

Question 22

A 3-year-old boy who exhibits prolonged bleeding after minor trauma and a prolonged aPTT, but normal platelet count, likely has

A) hemophilia.
B) liver dysfunction.
C) disseminated intravascular coagulation.
D) thrombocytopenia.

Question 23

Disseminated intravascular coagulation may be treated with heparin therapy to

A) enhance fibrinolysis.
B) inhibit clotting factor consumption.
C) activate platelets.
D) enhance liver synthesis of clotting factors.

Question 24

A deficiency of von Willebrand factor impairs

A) activation of the coagulation cascade.
B) platelet aggregation.
C) platelet adhesion to injured tissue.
D) platelet production.

Question 25

Treatment for hemophilia A includes

A) heparin administration.
B) factor IX replacement.
C) factor VIII replacement.
D) platelet transfusion.