Page 454 - Atlas of Histology with Functional Correlations

The spleen does not exhibit a cortex and a medulla, as seen in lymph nodes;

however, lymphatic nodules (4, 6) are found throughout the organ. In addition,
the spleen contains venous sinuses (13), in contrast to lymphatic sinuses of the
lymph nodes. The spleen also does not exhibit subcapsular or trabecular sinuses.
The capsule (1) and trabeculae (3, 5, 11) in the spleen are thicker than those in
the lymph nodes and with some smooth muscle fibers.

FIGURE 11.13 ■ Spleen (panoramic view). Stain: hematoxylin and eosin. Low

magnification.

FIGURE 11.14 | Spleen: Red and White Pulp

A higher magnification of a section of the spleen illustrates the red and white
pulp and associated connective tissue trabeculae, blood vessels, venous sinuses,
and splenic cords.

The large lymphatic nodule (3) represents the white pulp of the spleen.
Each nodule exhibits a peripheral zone—the periarterial lymphatic sheath—with

densely packed small lymphocytes. The central artery (4) in the lymphatic
nodule (3) has a peripheral, or an eccentric, position; however, because the artery
occupies the center of the periarterial lymphatic sheath, it is called the central

artery. The cells in the periarterial lymphatic sheath are mainly T cells. A
germinal center (5) may not always be present. In the more lightly stained
germinal center (5) are found B cells, many medium-sized lymphocytes, some
small lymphocytes, and lymphoblasts.

The red pulp contains the splenic cords (of Billroth) (1, 8) and venous

sinuses (2, 9) that course between the cords. The splenic cords (1, 8) are thin

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