Which cell type is a component of the innate immune system?

Which cell type is a component of the innate immune system?

• A. Erythrocyte
• B. B Cell
• C. T Cell
• D. Polymorphonuclear Leukocyte

Answer: (D)

The innate immune system acts quickly and non-specifically to defend against pathogens. Polymorphonuclear leukocytes, primarily neutrophils, are classic innate defenders. They circulate in blood and rapidly migrate to sites of infection, where they engulf and destroy invading microbes through phagocytosis and release of antimicrobial substances. This response does not require prior exposure or antigen-specific receptors, which is a hallmark of innate immunity. Erythrocytes are red blood cells that carry oxygen, not immune cells. B cells and T cells are lymphocytes that drive adaptive immunity, providing targeted, specific responses and memory after encountering an antigen—B cells produce antibodies, and T cells mediate other targeted immune functions.

The innate immune system acts quickly and non-specifically to defend against pathogens. Polymorphonuclear leukocytes, primarily neutrophils, are classic innate defenders. They circulate in blood and rapidly migrate to sites of infection, where they engulf and destroy invading microbes through phagocytosis and release of antimicrobial substances. This response does not require prior exposure or antigen-specific receptors, which is a hallmark of innate immunity.

Erythrocytes are red blood cells that carry oxygen, not immune cells. B cells and T cells are lymphocytes that drive adaptive immunity, providing targeted, specific responses and memory after encountering an antigen—B cells produce antibodies, and T cells mediate other targeted immune functions.