Related Experiment Video
Updated: Jun 3, 2026

A Radio-telemetric System to Monitor Cardiovascular Function in Rats with Spinal Cord Transection and Embryonic Neural Stem Cell Grafts
Published on: October 7, 2014
Factor Xa: Thrombokinase from Paul Morawitz to J Haskell Milstone
1Department of Dermatology, Yale Medical School, 333 Cedar St, New Haven, CT, 06520-8059, USA. leonard.milstone@yale.edu.
Abstract:
In 1904 Paul Morawitz postulated that an enzyme, which he named thrombokinase, would be the primary activator of prothrombin. Fifty years passed before J Haskell Milstone isolated, purified and functionally characterized the enzyme we now call Factor Xa. This essay summarizes Milstone's work on thrombokinase, and finds context for why his efforts succeeded while others struggled.
Related Concept Videos
The JAK-STAT Signaling Pathway
Coagulation
Anticoagulant Drugs: Low-Molecular-Weight Heparins
Coagulation
During the coagulation phase, clotting factors, or procoagulants, play a vital role in initiating and progressing the coagulation cascade. This cascade is a series of reactions...
Extrinsic and Intrinsic Pathways of Hemostasis
The Extrinsic Pathway
The extrinsic pathway of coagulation is typically initiated by tissue damage that exposes blood to tissue factor (TF), a protein released by the damaged tissue cells outside the blood vessels—this interaction with TF triggers biochemical reactions involving specific clotting factors. The key player here is Factor VII, which forms a...
Clot Retraction and Fibrinolysis

