And this is an amplification process. It's a process by which we amplify the amount of ten that is formed because ultimately it's this ten that will go on to form blood clots as we'll see in just a moment. So once again the extrinsic pathway consists of these steps and it's a quick acting pathway. It reacts quickly to this rupturing within our blood, within our endothelial cell. So when the blood vessel ruptures it exposes a membrane glycoprotein on the damaged cell called the tissue factor TF which is actually attached to the membrane of that cell. Now TF binds to the active form of protein factor seven found in close proximity forming a dimer protein complex TF seven.