Splenic blood supply continued.

Identify central arterioles associated with the white pulp lymphoid follicles (periarteriolar lymphoid sheathes or PALS), as well as the marginal zone of these follicles (Figs. 14-24 and 14-25).

In the red pulp identify the splenic cords (of Billroth), seen at lower right, and the venous sinuses (Fig. 14-26). The latter are small in most of slide 68, but can be detected by their contents of red blood cells. Sheathed vessels and sinuses are seen more readily on slide 73, which is stained with a special stain that also demonstrates elastic fibers in the trabeculae. Try to find a vascular sinus showing the unusual nature of the lining endothelial cells or stave cells.

Trace the highly unusual path of blood in the spleen (through the arteries and into the venous sinuses) and indicate how this pathway relates to the spleen's function.

What is the functional relationship between the venous sinuses and the surrounding red pulp?

Next is the skin.