Kaplan Nursing Entrance Exam Practice 2025 – Comprehensive Prep

The cellular response of the immune system is primarily mediated by white blood cells, also known as leukocytes. These cells play a crucial role in identifying and attacking pathogens, such as bacteria, viruses, and other foreign invaders. Among the various types of white blood cells, lymphocytes (including T cells and B cells) are particularly significant in the adaptive immune response. T cells, for example, are involved in directly killing infected cells and regulating the immune response, while B cells produce antibodies.

In contrast, red blood cells are primarily responsible for transporting oxygen and carbon dioxide in the bloodstream, and do not play a role in immunity. Platelets are involved in the clotting process to prevent blood loss from injuries and do not participate in the immune response. Clotting factors are proteins that also play a role in hemostasis, not in the immune response. Thus, white blood cells are the central players in the cellular response of the immune system.