Which cells are primarily involved in phagocytosis?

• A. Basophils and eosinophils
• B. Macrophages and neutrophils
• C. B lymphocytes and T lymphocytes
• D. Dendritic cells and mast cells

Answer: (B)

Macrophages and neutrophils are the primary cells involved in phagocytosis, which is the process by which certain immune cells engulf and digest pathogens, debris, and other particles. Macrophages reside in tissues and play a crucial role in both the innate and adaptive immune responses, effectively consuming large quantities of foreign material and dead cells. Neutrophils are the most abundant type of white blood cells and are often the first responders to sites of infection, where they quickly engage in phagocytosis to eliminate invading microorganisms. This rapid recruitment and action are vital for controlling infections and initiating the inflammatory response.

In contrast, basophils and eosinophils, while important in allergic reactions and parasitic infections, do not primarily function through phagocytosis. B and T lymphocytes are key players in the adaptive immune system, with B cells primarily involved in antibody production and T cells in cellular immunity, but they do not perform phagocytosis directly. Dendritic cells can perform phagocytosis, but their main role is to process antigens and present them to T cells, and mast cells are primarily involved in allergy-related responses rather than phagocytosis.