Which leukocyte becomes a phagocytic macrophage after leaving the circulation?

Prepare for the Anatomy and Physiology II Milestone 1 Test with engaging questions, in-depth explanations, and focused study resources. Start your journey to excel in your exam!

Multiple Choice

Which leukocyte becomes a phagocytic macrophage after leaving the circulation?

Monocytes circulate in the blood and then move into tissues, where they differentiate into macrophages. These macrophages are large, highly phagocytic cells that engulf pathogens and dead cells and can present antigens to T cells. This transformation is why a circulating monocyte becomes a tissue macrophage. Lymphocytes stay as lymphocytes and drive adaptive immunity rather than becoming macrophages. Neutrophils are also phagocytic, but they don’t mature into macrophages; they act as rapid responders and have a short lifespan. Eosinophils handle parasites and allergic responses and likewise do not become macrophages. So, the leukocyte that becomes a phagocytic macrophage after leaving the circulation is the monocyte.

Monocytes circulate in the blood and then move into tissues, where they differentiate into macrophages. These macrophages are large, highly phagocytic cells that engulf pathogens and dead cells and can present antigens to T cells. This transformation is why a circulating monocyte becomes a tissue macrophage.

Lymphocytes stay as lymphocytes and drive adaptive immunity rather than becoming macrophages. Neutrophils are also phagocytic, but they don’t mature into macrophages; they act as rapid responders and have a short lifespan. Eosinophils handle parasites and allergic responses and likewise do not become macrophages.

So, the leukocyte that becomes a phagocytic macrophage after leaving the circulation is the monocyte.

More practice questions