TEM image, 5,000X (photo courtesy of V. P. Saprykin). The sections of segmented neutrophils demonstrate some parts of nuclei #1, #2, #3, #4 (segment bridges are not reflected by this plane of section). There is a prevalence of heterochromatin #1, #2 in the nuclei. The cytoplasm contains:

• non-specific granules #1, #2, which are larger; these granules are rounded, resembling lysosomes; they are the first to appear when neutrophils are maturing (primary granules)
• specific granules #1, #2, #3, #4 are smaller but more numerous; they are elongated (on transverse sections they look like circles), they appear later than primary ones (secondary granules)

TEM image, 10,000X (photo courtesy of G. N. Bulanova). When migrating from the blood into connective tissue, neutrophils (like other white blood cells) attach the the endothelium of vascular walls thanks to adhesive proteins (selectins, integrins) and form pseudopods penetrating between the neighboring endothelial cells #1, #2. A new projection is then filled by the cell cytoplasm and nucleus.

The cytoplasm of the neutrophils contains non-specific #1, #2 and specific #1, #2 granules. The vascular lumen includes some red blood cells, while there are certain cytoplasmic portions of connective tissue cells, as well as some transverse and oblique transverse sections of collagen fibrils in connective tissue.

If an inflammatory reaction develops, neutrophils are the first to appear in the damaged area, killing the majority of microorganisms. After that they die and are exposed to phagocytosis by macrophages.