Page 360 - Atlas of Histology with Functional Correlations

FIGURE 9.19 ■ Ultrastructure of myelinated axons in the CNS with a node of
Ranvier. Transmission electron micrograph. Courtesy of Dr. Mark DeSantis,
Professor Emeritus, WWAMI Medical Program, University of Idaho, Moscow,
ID. Approximately ×55,000.

FIGURE 9.20 | Microglia of Brain

This section of the brain was prepared with the Hortega method to show the

smallest neuroglial cells called microglia (2, 3). The microglia (2, 3) vary in
shape and often exhibit irregular contours, and the small, deeply stained nucleus
almost fills the entire cell. The cell processes of the microglia (2, 3) are few,
short, and slender. Both the cell body and the processes of microglia (2, 3) are
covered with small spines. Two neurons (1) and a capillary with red blood

cells (erythrocytes) (4) provide a size comparison with the microglia (2, 3).

Microglia are found in both the white and gray matter of the CNS and are the
main phagocytes of the CNS.

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