1.23 Response of the second inmune barrierVersion en ligne Response mechanism of the second inmune barrier in a skin wound. par Jorge Arizpe 1 The skin has an open wound and bacteria are getting inside the body. 2 Damaged cells release chemical messages and stimulate the Mastocytes to produce Histamine. 3 Mastocytes release histamine 4 Histamine increase affects blood vessels increasing it´s permeabililty and speed of flow 5 The white blood cells (Phagocytes)(purple ones) leave the blood vessels to eat the bacteria and dead debris