2. Circulating Granulocytes
The three frames in this image (100x) illustrate the different
granulocytes that are seen commonly in the peripheral blood.
Granulocytes are leukocytes, or white blood cells, that contain
cytoplasmic granules. Frame (a) demonstrates a basophil with the
obvious large basophilic granules typical of these granulocytes. The
nuclear segmentation of these cells is often difficult to appreciate
due to the heavy cytoplasmic granulation. Basophils are the least
common of the granulocytes in the peripheral blood. Basophilia -- or
increased number of basophils -- is frequently noted in
myeloproliferative disorders. The most abundant of the circulating
granulocytes is the neutrophil (b). The specific granules of these
cells are not readily identified with the light microscope. An
increase in their number (neutrophilia) may be seen in a variety of
conditions, including infections or tissue necrosis (as in myocardial
injury). The large red granules of eosinophils (c) are readily
apparent in this picture. Eosinophilia, an increase in eosinophils,
will be presented in the next image.
