11. White Blood Cells: Days to Years
White blood cells are the body’s frontline defenders, and their lifespans vary widely based on their type and function. Neutrophils, for example, may survive only a few days, quickly responding to infections.
In contrast, memory cells can persist for years, providing long-term immunity after exposure to pathogens. This diversity ensures both rapid and lasting protection against disease. For a comprehensive look at white blood cell turnover, visit NCBI Bookshelf.