Which type of leukocyte is the most common in the blood?

Neutrophils are indeed the most common type of leukocyte, constituting approximately 50-70% of the total white blood cell count in adults. These cells play a crucial role in the immune response, specifically in the defense against bacterial infections. They are the first responders to sites of infection and are known for their ability to ingest and destroy pathogens through a process known as phagocytosis.

The presence and predominance of neutrophils reflect the body's immediate response to inflammatory stimuli. Their high abundance in the bloodstream allows for a rapid deployment to areas where they are needed, making them essential in the early stages of immune defense.

In contrast, eosinophils, basophils, and lymphocytes serve different functions within the immune system. Eosinophils primarily combat parasitic infections and are involved in allergic reactions; basophils play a role in inflammation and allergic responses through the release of histamine; and lymphocytes are critical for the adaptive immune response, including the production of antibodies and the destruction of virus-infected cells. While all these leukocytes have vital roles in immune function, their proportions in the blood differ significantly from that of neutrophils, highlighting why neutrophils are the most prevalent leukocyte type.