class notes 7 - flashcards

Vocabulary flashcards related to Hemostasis

What is haemostasis?

The body's response to vascular injury, involving a series processes to prevent blood loss.

What is a thrombus?

An intravascular clotted mass of blood formed from inappropriate activation of haemostatic mechanisms, fixed in place.

What is an embolus?

A mass traveling in the bloodstream, often a bit broken off of a thrombus, which can cause blockages.

What occurs during syneresis?

The process of clot retraction that expels serum.

What is the role of von Willebrand's Factor (vWF)?

A linkage molecule or protein anchor that allows platelets to adhere to subendothelial collagen.

How does Tissue Factor initiate the procoagulant state?

A hidden membrane component exposed by endothelial damage, initiating a procoagulant state.

What are the Extrinsic and Intrinsic Coagulation Systems?

Two coagulation cascades that terminate in a common pathway, leading to fibrin formation.

Which clotting factors are Vitamin K-dependent?

Prothrombin (II) and factors VII, IX, X are dependent on it for their synthesis.

How does coumarin (warfarin) act as an anticoagulant?

An anticoagulant rodenticide that inhibits the action of vitamin K.

What is the function of Antithrombin III (AT-III)?

A circulating anticoagulant that inactivates thrombin.

What role does endothelin play in vasoconstriction?

A vasoconstrictor secreted by endothelium following injury.

How does Thromboxane (TXA2) amplify platelet activation?

A factor secreted by platelets that activates more platelets and causes the plug to grow.

How does Fibrin Stabilizing Factor contribute to clot stability?

Secreted from platelets and forms covalent bonds between fibrin strands.

How does Prostacyclin (PGI2) counteract platelet aggregation?

Secreted by endothelial cells adjacent to the injury that cause vasodilation and inhibit platelet aggregation.

What is the role of Tissue Plasminogen Activator (t-PA)?

Secreted by endothelium and converts plasminogen to plasmin, initiating clot breakdown.

How does plasmin degrade fibrin?

Breaks down fibrin, forming fibrin degradation products (FDPs).

What is the significance of Fibrin Degradation Products (FDPs)?

Formed by breakdown of fibrin by plasmin and have a mild anticoagulant effect.

What does the presence of D-dimer indicate?

A specific type of FDP, formed only after fibrin has been stabilized (cross-linked) by Fibrin Stabilizing Factor.

Why is thrombocytopaenia the most common cause of bleeding in dogs and cats?

The most common cause of bleeding in dogs and cats, characterized by a deficiency of platelets.

What does bleeding time measure?

An estimate of time to form the primary platelet plug; assesses platelet function.

Which coagulation cascades are evaluated by the Activated Clotting Time (ACT)?

Evaluates intrinsic and common coagulation cascades.

What aspect of the coagulation system is assessed by the Activated Partial Thromboplastin Time (APTT)?

Evaluates intrinsic and common coagulation systems.

Which coagulation systems are evaluated by Prothrombin Time (PT)?

Evaluates the extrinsic and common systems; more sensitive at detecting coumarin poisoning than APTT or ACT.

What condition is detected by the Thrombin Clot Time (TCT)?

Detects hypofibrinogenaemia.

What is Hypofibrinogenaemia?

Low levels of fibrinogen in blood.

What is the factor designation for Fibrin?

Factor Ia.

What is the factor designation for Fibrinogen?

Factor I.

What is the factor designation for Thrombin?

Factor IIa.

What is the factor designation for Prothrombin?

Factor II.

What is the common name designation for Factor III?

Thromboplastin, Factor III.

What is the function designation for Factor Xa?

Prothrombin activator.

What is the common name designation for Factor XII?

Hageman factor.

What is the common name designation for Factor V?

Proaccelerin.

What is the common name designation for Factor XIII?

Factor XIII.

What is the function of High Molecular Weight Kininogen (HMWK)?

Accelerates conversion of Factor XII to XIIa.

How does ADP affect platelet aggregation?

Activates more platelets and cause the plug to grow.

How would you describe the function of Heparin?

Increases the activity of AT-III, enhancing its anticoagulant effects.

What is the function of Thrombomodulin?

Binds thrombin to activate protein C, which cleaves activated factors V and VIII, inhibiting coagulation.

What is the process that creates serum?

Plasma that is devoid of clotting factors.