Page 206 - Atlas of Histology with Functional Correlations

This illustration shows numerous erythrocytes (1) and platelets (2) that are

usually seen in a blood smear. Blood platelets (2) are the smallest elements; they
are nonnucleated cytoplasmic remnants of large-cell megakaryocytes, which are
found only in the red bone marrow. Platelets (2) appear as irregular masses of
the basophilic (blue) cytoplasm, and they tend to form clumps in blood smears.
Each platelet exhibits a light blue peripheral zone and a dense central zone

containing purple granules.

FIGURE 6.4 ■ Erythrocytes and platelets in a blood smear. Stain: Wright stain.
Oil immersion.

Figure 6.5 | Neutrophils

The leukocytes that contain cytoplasmic granules and lobulated nuclei are the
polymorphonuclear granulocytes, of which the neutrophils (2) are the most
abundant. The neutrophil cytoplasm (2) contains fine violet or pink granules that

are difficult to see with a light microscope. As a result, the cytoplasm (2) of the
neutrophils appears clear or neutral. The nucleus of the neutrophils (2) consists
of several lobes connected by narrow chromatin strands. Immature neutrophils
contain fewer nuclear lobes.

In human blood smears, an inactivated X chromosome of the female donor

can be occasionally recognized as a Barr body (1) or a drumstick, which is a
small extension of the chromatin next to one of the nuclear lobes. Numerous
cells need to be examined in order to find the right orientation of the neutrophils

205