Question

Help please. Can someone give me a decent explanation/answer to this question?? 3. What is the importance of diapedesis, chemotaxis and phagocytosis in fighting bacterial invasion? Thanks :)

Answer 1

All the terms refer to mechanisms necessary to leukocytes to reach the site of infection and destroy the invading bacteria.
Diapedesis means the movement of leukocytes out of blood vessels, where they normally reside, to reach the site of infection. It is a complex process which requires several proteins and the interaction with the cells forming the capillary wall.
To reach the site of infection, leukocytes sense and follow chemical signals in the form of small molecules released by the bacteria, and this is termed chemoattraction, or chemotaxis.
Finally, once at the infection site, leukocyte eliminate the pathogens by "eating" them and destroying them in apposite cytoplasmic organelles called lysosomes. This process is termed phagocytosis.