AEMCA Practice Exam

Which of the following blood cells is involved in fighting off infections?

1. Red blood cells

2. Platelets

3. Monocytes

4. All of the above

The correct answer is: Monocytes

Monocytes play a crucial role in the immune response and are a type of white blood cell specifically involved in fighting off infections. They are part of the body's defense system, working to identify and eliminate pathogens such as bacteria and viruses. Once they enter tissues, monocytes can differentiate into macrophages and dendritic cells, which are essential in engulfing and digesting pathogens. They also help in activating other immune cells and coordinating the overall immune response, making them vital in protecting the body against infections. In contrast, red blood cells primarily function to transport oxygen and carbon dioxide throughout the body, and while they are essential for overall health, they do not have a role in the immune defense. Platelets, on the other hand, are involved in blood clotting and repair of damaged blood vessels. While they play an important role in the healing process, they are not directly involved in fighting off infections like monocytes are. Thus, the selection of monocytes as the answer reflects their specific contribution to the immune system.