Microbiology Practice Exam

Which leukocyte is primarily involved in the inflammatory response?

1. Neutrophil

2. Lymphocyte

3. Eosinophil

4. Basophil

The correct answer is: Neutrophil

The neutrophil is the leukocyte that plays a primary role in the inflammatory response. When tissue injury occurs or an infection is present, neutrophils are among the first immune cells to arrive at the site of inflammation. They are crucial for the initial response to pathogens due to their ability to phagocytize (engulf and digest) bacteria and debris, as well as release enzymes and antimicrobial substances that help to contain and eliminate infections. Neutrophils are part of the innate immune system and have a short lifespan, typically lasting just a few hours to a few days in tissues but can rapidly multiply in response to inflammation. Their presence and action result in the classic signs of inflammation, such as redness, heat, swelling, and pain. While lymphocytes are important in the adaptive immune response and contribute to longer-term immunity, they are not the primary responders during the acute phase of inflammation. Eosinophils primarily deal with parasitic infections and certain allergic responses, while basophils release histamine and other mediators that assist in the inflammatory response, but they are not the primary leukocyte acting in the early stages. Thus, neutrophils are the most significant players in the immediate inflammatory response.