Final answer:
Wandering macrophages originate from monocytes, which transform into macrophages after exiting the bloodstream and entering infected tissue.
Step-by-step explanation:
Wandering macrophages develop from monocytes after exiting the blood. Monocytes, a type of white blood cell, circulate in the blood and lymph systems and differentiate into macrophages when they move into infected tissue.
They are vital components of the immune system, involved in engulfing and digesting pathogens, presenting antigens for the adaptive immune response, and releasing cytokines to recruit other immune cells. While some macrophages remain fixed in tissues, others are free to move through the tissue fluid, rapidly doing so by amoeboid movement.