Coagulation cascade, the cell-based model and coagulation tests
The classical cascade as a map of laboratory tests, the cell-based model of how thrombin is really made, vitamin K-dependent factors, and how to interpret PT, INR, APTT, thrombin time and mixing studies.
Tier 1Medical sciences concept
Written with AI assistance and fact-checked against the sources below. For exam study, not clinical decisions. How notes are made
At a glance
- The classical cascade (extrinsic, intrinsic, common pathways) describes test tubes. It explains the PT and APTT, not how people stop bleeding.
- The cell-based model puts coagulation on cell surfaces: initiation on tissue factor-bearing cells, amplification by a little thrombin, and a thrombin burst on activated platelets.
- Tissue factor (TF) with factor VIIa starts coagulation in vivo. Factors VIII and IX sustain it, which is why haemophilia bleeds and factor XII deficiency does not.
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Sources
- A cell-based model of hemostasisThrombosis and Haemostasis (Hoffman and Monroe, 2001;85:958-965), 2001
- The coagulopathy of chronic liver diseaseNew England Journal of Medicine (Tripodi and Mannucci, 2011;365:147-156), 2011
- International recommendations on the diagnosis and treatment of acquired hemophilia AHaematologica (Tiede et al., 2020;105:1791-1801), 2020
- Postgraduate Haematology (7th ed.)Wiley-Blackwell (Hoffbrand, Higgs, Keeling and Mehta, 2016), 2016
- Hoffbrand's Essential Haematology (8th ed.)Wiley-Blackwell (Hoffbrand and Steensma, 2019), 2019
- Last updated
- 14 November 2026
What changed
- 14 November 2026 Personal emails, About story and Australian-style copy