Qualified Medication Aides (QMA) Practice Exam

What is the primary function of white blood cells?

1. Transport oxygen

2. Fight infection

3. Regulate blood pressure

4. Clot blood

The correct answer is: Fight infection

White blood cells, also known as leukocytes, play a crucial role in the body's immune system by fighting infection. Their primary function is to identify and eliminate pathogens such as bacteria, viruses, fungi, and parasites that can cause illness. They do this through various mechanisms, including the production of antibodies, the destruction of infected cells, and the signaling of other immune cells to respond to threats. Unlike red blood cells, which are responsible for transporting oxygen throughout the body, white blood cells do not have this function. Similarly, the regulation of blood pressure and the clotting of blood are functions performed by different systems and types of cells; for instance, platelets are involved in blood clotting, while the circulatory system regulates blood pressure. Thus, the primary role of white blood cells distinctly centers on their ability to protect the body from infections and maintain overall health.