Hemodynamics

The hemodynamics describes the flow of blood in the blood vessels as a function of the responsible forces.

Various parameters are crucial for the fluid mechanics of blood:

• The geometry of the vessel
• The elasticity of the vessel
• The pressures prevailing in
• The cardiac output ( locally known as flow rate )
• The volume of blood
• The blood composition

Recent studies show that the hemodynamics not only for the flow of blood in itself is significant, but that hemodynamic forces have significant influence on the physiology of the endothelium and vascular smooth muscle. The endothelial cells are able changes in blood pressure and the shear stress perceive and control depends on the vascular smooth muscle to regulate these parameters. Thus, an increase in shear stress leads to a release of vasodilatory substances that reduce blood pressure and the flow rate again by expanding the vessel lumen. Another effect is the release of a growth factor for vascular smooth muscle cells, which guarantee the mechanical stability of the larger and medium-sized blood vessels. These mechanisms provide an autoregulation of blood flow dar.

Moreover, the hemodynamic but essential for the survival of the vessel. If the hemodynamic stimuli disappear or even the laminar blood flow is unsteady, the endothelium of the affected vessel with apoptosis, which ultimately leads to the degradation of the whole vessel responding. For a brief flow disturbance not already leads to a complete breakdown of the endothelium via apoptosis, this process is a first in only a few cells and only leads for longer stop the disturbed state into a complete vessel removal.