Anatomy and Physiology II Practice Test

Macrophages were originally which type of cell that migrated into tissues?

1. Neutrophils

2. Basophils

3. Monocytes

4. Lymphocytes

The correct answer is: Monocytes

Macrophages are specialized immune cells that play a crucial role in the body's defense mechanisms. They originate from a type of white blood cell called monocytes, which are produced in the bone marrow. After monocytes are released into the bloodstream, they migrate into various tissues throughout the body in response to signals from sites of infection or injury. Once in the tissues, monocytes differentiate into macrophages, which can then take on various roles, such as phagocytosis (engulfing and digesting pathogens and debris), antigen presentation (showing pieces of pathogens to T cells to initiate an immune response), and the release of cytokines to recruit and activate other immune cells. This transition is vital for the development of an effective immune response, allowing for increased specialization in the handling of pathogens. The other cell types listed, such as neutrophils, basophils, and lymphocytes, have distinct functions and origins within the immune system. Neutrophils are primarily involved in the rapid response to infection and are recruited to sites of inflammation, basophils play a role in allergic responses, and lymphocytes are integral to adaptive immunity. Although important, these cells do not transform into macrophages, highlighting the unique origin of macrophages from monocytes