Biology – The circulatory system | e-Consult

(a) Identification of the White Blood Cell:

The white blood cell is most likely a macrophage.

(b) Function of the Structure (Phagosome):

The circular structure is a phagosome, which is formed when a phagocyte (like a macrophage) engulfs a particle such as a bacterium or cellular debris. The phagosome fuses with lysosomes to form a phagolysosome. The lysosomal enzymes within the phagolysosome then digest the engulfed material. This process is a crucial part of the innate immune system, as it allows phagocytes to eliminate pathogens and cellular waste, preventing infection and tissue damage. Macrophages are key players in both innate and adaptive immunity, acting as antigen-presenting cells to activate T lymphocytes.