The title of this module is Tissue Factor and
Factor VII -.Initiation of Blood Coagulation.
My name is John McVey.
The learning objectives are to introduce the coagulation network,
to give you an understanding of how this complex process is regulated,
and how it functions at the molecular level.
In particular, focusing on the role of Tissue Factor and
Factor VII complex in initiating coagulation,
looking at their structure and function but also the role of tissue factor
pathway inhibitor and regulating the activity of this initiation complex.
Finally, I will discuss the pathophysiological consequences of
inappropriate expression or deficiency.
The ability to stem the flow of body fluids at the sight of
vascular injury is a very primitive defense mechanism.
This is critical for the survival of any multicellular organism,
both in preventing loss but also preventing entry of organisms and pathogens.
Organisms have adopted a variety of
different methods to achieve this, tissue contraction,
cellular aggregation, and the formation and deposition of molecular glues.
Vertebrates have evolved a complex system that includes blood vessel
constriction, cellular aggregation involving specialized cells,
platelets, and the deposition of an insoluble polymer fibrin,
that results in the formation of a stable clot at the site of injury.
In this scanning electron micrograph,
you can see the fibrin mesh work in trapping red and white blood cells.
Although this teaching session will focus on
the processes that regulate the initiation of
coagulation leading to Thrombin generation and the formation of a stable fibrin clot,
it should be appreciated that the process of
platelet activation and Thrombin generation are intimately linked.
Platelets provide a surface for the promotion and assembly of
procoagulant complexes and a source of coagulation factors.
Conversely, Thrombin is a potent activator of platelets.