Basophils are the same size as eosinophils, but have purplish to blue-black granules. Agranular WBC also come from red bone marrow, but require further maturation in lymphoid tissue. They have NO granules. They have spherical nuclei and include lymphocytes and monocytes . They take longer than neutrophils to get to the damaged site, but arrive in greater numbers and destroy more organisms.
Monocytes are also phagocytic and clean up cellular debris following an infection.
Functions of WBC include combating inflammation and infections. Most WBC have the ability to crawl through capillary walls and connective tissue. This capability is called diapedesis or cell walking, Figure 12 . Once the WBC is in the tissue, it migrates to the site from where the signal for its need arises. The last type of agranular WBC, the lymphocyte, has been saved for this spot.