Fåhræus-Lindqvist effect

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The Fåhræus-Lindqvist effect is the decrease in the apparent viscosity of the blood as the diameter of a vessel decreases .

In vessels with a diameter of 7 to 10 micrometers, the apparent viscosity of the blood is only slightly higher than that of the plasma. The decrease in the apparent viscosity is due to the fact that the erythrocytes in the middle of the blood stream move faster due to lower shear forces, which causes an increased displacement there (axial migration) . This creates a low-cell sliding layer (edge ​​zone) that accelerates the movement of the central fluid. In addition, erythrocytes are easily deformable ( fluidity ) and can thus adapt to a changed shear stress and thereby reduce hemodynamic disruptive effects.

Due to the Fåhræus-Lindqvist effect, the hematocrit has only a minor influence on the size of the peripheral resistance in small vessels.

literature

  • Robert F. Schmidt, Florian Lang (ed.): Human physiology: with pathophysiology . 30th edition. Springer, Heidelberg 2007, ISBN 978-3-540-32908-4 , p. 623.