Normal Mechanisms of Haemostatic Control

Vascular Response

There are several possible vascular responses, of which one or more may be recruited in normal haemostasis.

1. Vascular contraction: This is usually a temporary process which gives a partial arrest of blood flow. It is an important mechanism in larger vessels.
2. Vascular shunting: Blood is redistributed using alternative pathways to by-pass the injured area.
3. Increased blood viscosity: This is also known as the "sludging" effect; the RBCs become more densely packed due to plasma loss through vascular walls and leaky plugs.
4. Plasma loss: Loss of plasma to the surrounding tissue spaces results in pressure on the vessel walls.