Hemostasis- Physiology

The process by which the body stops the bleeding after an injury is called:

Hemostasis

Platelet aggregation is blocked upon use of which of the following medications? Please select the single

Heparin

Which of the following best represents the quantity of resultant bleeding in order of smallest bleed to largest (assuming identical trauma)?

Venule, Vein, Artery

A deficiency in which of these vitamins leads to increased clotting time and may result in hemorrhagic disease?

Vitamin K

A defect in which of the following factors causes impaired platelet adhesion and aggregation?

Von Willebrand factor

Aspirin ingestion prevents the synthesis of this signaling molecule in the platelet?

Thromboxane A2

A substance secreted by the vascular endothelial cells that can help to initiate fibrinolysis is:

Tissue plasminogen activator (t-PA)

Each of the following has been shown to induce platelet aggregation EXCEPT?

Aspirin

An abnormality of which of the following assays would be LEAST likely to be associated with thrombotic tendency?

APTT

Which of the following laboratory tests of hemostatic function is a screening test used to assess the functionality of both the intrinsic and common pathways?

Activated partial thromboplastin time (aPTT)

Which of the following chemical substances induces platelet adhesion when there is a break in the inert epithelial lining of the vasculature?

Adenosine diphosphate (ADP)

What is the ultimate goal of secondary hemostasis?

Formation of a fibrin clot

Platelets are:

Fragments of megakaryocyte cytoplasm and do not contain nuclei

What is the function of ADAMTS13 enzyme?

Cleaving ultra-large von Willebrand factor to keep them out of the circulation

Which of the following statements regarding coagulation disorders is correct?

Clotting factors II, VII, IX and X are vitamin K-dependent.

Blood serum contains each of the following substances except:

Coagulation proteins

In the in vitro coagulation scheme, factor V is primarily involved in the:

Common pathway

Which coagulation pathway is factor VII part of?

Extrinsic

The prothrombin time test will detect deficiencies in which pathways?

Extrinsic and common pathways

Which of the following coagulation pathways includes Factor VII?

Extrinsic pathway

Which of the following factors is Vitamin K-dependent?

Factor IX

All of the following factors are involved in the intrinsic pathway, EXCEPT?

Factor VII

Which coagulation factor is found ONLY in the extrinsic pathway?

Factor VII

Which of the following factors does not affect the result of the aPTT assay?

Factor VII

Which of the following factors require Vitamin K for their synthesis in the liver?

Factor VII

Which of the following options best describes how hemophilia A differs from hemophilia B?

Factor VIII is deficient in hemophilia A and factor IX is deficient in hemophilia B.

All of the following factors are involved in the initial contact phase of the intrinsic pathway, EXCEPT:

Factor X

Warfarin (coumarin-type anticoagulant) inhibits all the following coagulation factors except:

Factor XI

Which of the following factors is known as Hageman factor?

Factor XII

The fibrin clot begins to form when fibrinogen is cleaved resulting in a fibrin monomer, fibrinopeptide A, and fibrinopeptide B fragments. The fibrin monmers sponaneously polymerize due to hydrogen bonding, and then are covalently linked into fibrin polymers by which factor?

Factor XIII

Which of these coagulation factors are referred to as "vitamin-K dependent"?

Factors II, VII, IX, X

Plasmin is known to degrade Factors Va, VIIIa, and GPIb. What other substance is it known to digest?

Fibrin

Which of the following processes does NOT occur during primary hemostasis?

Fibrin strands added to the newly formed clot.

What additional fraction would be seen if plasma rather than serum was subjected to electrophoresis:

Fibrinogen

Which of the following is found in plasma but absent in serum?

Fibrinogen

What is the term that describes the process by which fibrin strands are broken down and then removed from an established clot?

Fibrinolysis

What may prevent the detection of lupus anticoagulant in a plasma sample if the blood used for testing is not centrifuged for a sufficient time?

Increased platelets in the plasma sample

Which coagulation pathway is initiated when collagen is exposed, and involves the substances high-molecular-weight kininogen (HK), prekallikrein (PK), and factor XII?

Intrinsic

A defective clot retraction might be caused by which one of these?

Lack of or defect of platelet receptor IIb/IIIa

What organ is associated with the production of the majority of clotting factors?

Liver

All of the following statements describe a method by which platelets aid coagulation EXCEPT:

Lower blood pressure by releasing heparin

All of the following activities are associated with platelets EXCEPT:

Lysis

A 3-year-old child was brought into the hospital with complaints of recurring conjunctivitis along with "woody" growths on the mucous membranes. Which of the following deficiencies would occur given these symptoms?

Plasminogen

The thrombomodulin-thrombin complex is known to aid in the activation of which of the following

Plasminogen

Which of the following is responsible for inhibiting the tissue plasminogen activator?

Protein C

Which of the following is the common name for factor II?

Prothrombin

Which condition is caused by the increased Plasminogen Activator Inhibitor 1 (PAI-1) and fibrinogen often present in metabolic syndrome?

Prothrombotic state

The vascular system contributes to hemostasis in all of the following ways EXCEPT:

Providing smooth endothelial surface

Which of the following statements is true regarding primary hemostatic process resulting from vascular damage?

Rapid and immediate vasoconstriction by contraction of smooth muscles.

Which of the following mechanisms involves a series of interrelated chemical processes that lead to the formation of durable fibrin strands?

Secondary hemostasis

Removal of which of these organs may be a last resort treatment for a patient whose platelet count is less than 30 x 109/L as a result of chronic idiopathic thrombocytopenic purpura (ITP)?

Spleen

The fibrinolytic system may be activated by which one of the following?

Streptokinase

Which of the following converts Fibrinogen into Fibrin Monomer?

Thrombin

Obstruction of a blood vessel caused by a stationary blood clot is called:

Thrombosis