Spleen: white pulp

When an arteriole leaves a trabecula and enters the parenchyma of the spleen, it is immediately surrounded by a sleeve of T-dependent, diffuse lymphatic tissue termed the periarterial lymphoid sheath, PALS.  Because the arteriole is located near the center of the PALS, it is called the central arteriole.  PALS forms one portion of the white pulp.  400x

When an arteriole leaves a trabecula and enters the parenchyma of the spleen, it is immediately surrounded by a sleeve of T-dependent, diffuse lymphatic tissue termed the periarterial lymphoid sheath, PALS.  Because the arteriole is located near the center of the PALS, it is called the central arteriole.  PALS forms one portion of the white pulp.  400x

Red pulp fills all the areas in the image not occupied by the trabecula and white pulp.

Red pulp fills all the areas in the image not occupied by the trabecula and white pulp.

Image taken of a slide from the University of Michigan collection.