Image: spleen of a rat, stained with hematoxylin-eosin.
Capsule: it is a layer of connetive tissue coating the outer surface of the spleen.
Trabeculae: they are layers of connective tissue that extend from the capsule into the spleen and divide the organ in compartments.
Red pulp: it is a region of the spleen with a characteristic red color in fresh tissue because of the large amount of venous blood vessels. In this image, it shows a white color because the blood was removed during the histological process.
White pulp: it is the region around the central artery, made up of a dense population of lymphoid cells.
Stroma: it is the interior part of the spleen consisting of connective tissue, reticular fibers and fibroblasts. Many macrophages are also observed.
Central artery: it is the blood vessel in the center of the red pulp.
PALS: (Periarterial lymphoid sheath) is the layer of cells that wrap the arteries of the white pulp.