Leucocyte — Fast & Quick

: The most numerous, acting as first responders to infection.

: They move from the bloodstream into tissues via the lymphatic vasculature using chemokine-directed "amoeboid movement".

Leucocytes are generally classified by their cell lineage into or lymphoid cells and further divided based on the presence of granules in their cytoplasm: Granulocytes : Contain visible granules and include: leucocyte

: Large cells that migrate into tissues to become macrophages, which engulf debris and pathogens.

: Primarily involved in battling parasitic infections and allergic responses. : The most numerous, acting as first responders to infection

: Specific cell adhesion molecules (CAMs) allow leucocytes to stick to vascular endothelial cells, a process essential for reaching the site of an injury or infection.

: Certain leucocytes, like neutrophils and macrophages, ingest and destroy harmful germs and cellular debris. : Primarily involved in battling parasitic infections and

: Key players in the adaptive immune system, further divided into T cells (cell-mediated immunity) and B cells (antibody production). Function and Mechanism