Kaplan Nursing Entrance Practice Exam

What are lymphocytes primarily involved in?

1. Producing carbon dioxide

2. Regulating blood flow

3. Coordinating immune responses

4. Filtering air

The correct answer is: Coordinating immune responses

Lymphocytes are a type of white blood cell that plays a critical role in the immune system. Their primary function is to coordinate immune responses against pathogens, which include viruses, bacteria, and other foreign invaders. They achieve this through various mechanisms, including recognizing antigens, producing antibodies, and signaling other immune cells to respond effectively. There are different types of lymphocytes, including B cells, which are responsible for antibody production, and T cells, which can directly kill infected cells or help regulate the immune response. The other options involve processes not directly related to the function of lymphocytes; for instance, producing carbon dioxide is primarily a metabolic process carried out by cells during respiration. Regulating blood flow is a function of the cardiovascular system and involves different types of cells, not specifically lymphocytes. Filtering air is a function associated with the respiratory system, particularly the structures within the lungs and nasal passages, which helps prevent pathogens from entering the body. Thus, lymphocytes are distinctly focused on immune coordination, which encompasses their significant role in protecting the body from infections and diseases.