Hemostasis and Coagulation

A set of flashcards to help review key concepts related to hemostasis and coagulation for exam preparation.

What are the primary functions of the hemostatic system?

Primary hemostasis involves vasoconstriction and platelet plug formation; secondary involves fibrin clot stabilization; fibrinolysis is clot breakdown; and regulation prevents excess clotting.

Describe the role of the coagulation cascade's extrinsic pathway.

The extrinsic pathway involves tissue factor (TF) and factor VII activating factor X, leading to Xa.

What components are involved in platelet aggregation?

Platelet aggregation involves GPIIb/IIIa and is activated by ADP and thromboxane A2 (TXA2).

What is the significance of INR in coagulation monitoring?

INR monitors the effect of warfarin; the target range is typically between 2.0 and 3.0.

What are the main roles of platelets in hemostasis?

Platelets adhere using GPIb, aggregate with GPIIb/IIIa, release contents from dense granules (ADP, serotonin) and alpha granules (vWF, fibrinogen), and provide a phospholipid surface.

Define DIC and its laboratory findings.

DIC is disseminated intravascular coagulation, commonly associated with sepsis or trauma, characterized by elevated PT/aPTT/D-dimer and decreased platelets and fibrinogen.

What are the differences between factor bleeding and platelet bleeding?

Platelet bleeding typically involves mucosal areas, while factor bleeding leads to deep tissue hemorrhages.

List some common acquired defects affecting coagulation.

Acquired defects can be due to drugs like aspirin and clopidogrel, or conditions such as disseminated intravascular coagulation (DIC) and uremia.

What are the key anticoagulants and their monitoring methods?

Heparin is monitored by aPTT, LMWH targets factor Xa, Warfarin by INR, and DOACs include dabigatran and rivaroxaban.

What is the role of plasmin in the coagulation process?

Plasmin degrades fibrin and breaks down the clot.