List of slides

Eosinophil

TEM image, 6,000X (photo courtesy of V. P. Saprykin). The eosinophil nucleus is bilobed, it is full of heterochromatin (mainly in the nuclear periphery). The cytoplasm contains:

non-specific granules that are round-shaped, not numerous
specific granules that are the most common in the cell, their shape is elliptical and elongated; there are crystalloid structures floating in the matrix with small granules

The crystalloid and matrix density may vary depending on the type of granules #1, #2, #3. Shorts pseudopods #1, #2 are found on the cell surface; their number increases after an eosinophil migrates to connective tissues.

TEM image, 21,000X. A cytoplasmic portion of the eosinophil near the nucleus contains a mitochondrion and specific granules. Some crystalloid is floating in the matrix along the longitudinal granule axis.

Besides protective (antiparasitic) function, eosinophils exert a regulatory function: they downregulate immune reactions (including allergic ones) and act as antagonists to mast cells and basophils.