diapedesis is now supposed to be the result of blood pressure, but it occurs in snakebite, where blood pressure is at zero.
It is supposed that in many such cases the hemorrhage is due to diapedesis, and not to rupture of a blood-vessel (rhexis).
That leading feature of viper poison, diapedesis with hæmorrhage, does not occur with either.
The theory of blood pressure may apply to diapedesis accompanying the inflammatory process.
This escape of red corpuscles is known as diapedesis, and is sometimes so extensive as to amount to capillary hemorrhage.
To the number of these there is possibly an addition by the immigration from below (diapedesis) of leucocytes.
diapedesis di·a·pe·de·sis (dī'ə-pĭ-dē'sĭs)
The movement or passage of blood cells, especially white blood cells, through intact capillary walls into surrounding body tissue. Also called migration.