Coagulation Cascade
Step 3 — Secondary Haemostasis (Coagulation Cascade): Coagulation factors are sequentially activated, generating thrombin, which converts fibrinogen to fibrin.
What our notes say
- Step 3 — Secondary Haemostasis (Coagulation Cascade): Coagulation factors are sequentially activated, generating thrombin, which converts fibrinogen to fibrin. (Haemostasis & Coagulation: Platelet Function & Bleeding Disorders)
- Haematoma formation (within hours): bleeding from the fracture ends and disrupted periosteal/endosteal vessels forms a haematoma; this activates the coagulation cascade and releases cytokines/growth factors (e.g. (General & Systemic Pathology SAQ Paper II — 15 July 2025 (MBPA 3500, MKU Year 3,)
- A loose primary platelet plug forms, later reinforced by fibrin from the coagulation cascade (Haemostasis & Coagulation: Platelet Function & Bleeding Disorders)
- Released RBC contents and inflammatory mediators activate the coagulation cascade → DIC (Disseminated Intravascular Coagulation) (Blood Transfusion Contraindications & Acute Reactions)
- Most common clinical associations: Sepsis, obstetric complications, malignancy, and major trauma (especially brain trauma — releases fat and phospholipids which activate the intrinsic coagulation cascade). (Hematologic Malignancies and Bleeding Disorders)
Study material on Coagulation Cascade
Practice questions on Coagulation Cascade
End product of the coagulation cascade?
- Platelet plug
- Soluble fibrinogen
- Insoluble fibrin clot
- Plasmin
Answer: C. Thrombin cleaves fibrinogen → fibrin monomers → polymerize → cross-linked by Factor XIIIa into a stable insoluble clot. ---
The coagulation cascade's final common pathway begins with activation of
- Factor XII
- Factor X
- Factor VIII
- Factor II (prothrombin)
Answer: B. Factor Xa combines with Factor Va (prothrombinase complex) to convert prothrombin to thrombin — the start of the common pathway. ---
What is the end product of the coagulation cascade? ---
- Platelet plug
- Soluble fibrinogen
- Insoluble fibrin clot
- Plasmin Answer:
Answer: A.