Which blood cell type is primarily involved in the immune response?

Leukocytes, also known as white blood cells, are the primary cells involved in the immune response. They play a crucial role in defending the body against both infectious disease and foreign invaders. Unlike red blood cells, which are primarily responsible for transporting oxygen, and platelets, which are essential for blood clotting, leukocytes are specialized for identifying, attacking, and eliminating pathogens such as bacteria, viruses, and other foreign substances.

Leukocytes encompass various cell types, including lymphocytes (T cells and B cells) and phagocytes (like neutrophils and macrophages), each serving distinct functions in the immune system. T cells are vital for cell-mediated immunity, while B cells produce antibodies, contributing to humoral immunity. Phagocytes, such as neutrophils, engulf and digest pathogens directly. Overall, leukocytes are critical for a well-functioning immune system, making them the key players in immune responses.