Eosinophils are granulocytes that play a role in defending against parasitic worms. They secrete their granule contents onto worms, which helps kill them. They also play a role in allergic asthma. Figure 2-10B . E. Mast cells are functionally similar to basophils but are not derived from basophils.
Mast cells are present in tissues.
F. Dendritic cells are so called because of the long dendritic extensions of plasma membrane that they possess. While their are many names for dendritic cells, it is important to know that follicular dendritic cells are completely different from the dentritic cells that help T cells. Dendritic cells that present antigen to T helper cells include interstitial dendritic cells, veiled cells in the blood, and interdigitating dendritic cells found in lymphoid tissues. They are all the same kind of cell, just found in different locations. This kind of dendritic cell is formed in the bone marrow along with all the other blood cells.