All of the following are the components of the white pulp of spleen, except (AIPG 2011)
|A||Periarteriolar lymphoid sheath|
|C||Antigen presenting cells|
White pulp: The altered coat of the arterioles, consisting of adenoid tissue, presents here and there thickening(s) of a spheroidal shape, (Malpighian bodies of the spleen, splenic lymphoid nodules).
These bodies vary in size from about 0.25 mm. to 1 mm. in diameter.
They are merely local expansions or hyperplasia of the adenoid tissue, of which the external coat of the smaller arteries of the spleen is formed.
They are most frequently found surrounding the arteriole, which thus seems to tunnel them, but occasionally they grow from one side of the vessel only, and present the appearance of a sessile bud growing from the arterial wall.
The red pulp (also called splenic pulp, but should not be confused with white pulp) is a soft mass of a dark reddish-brown color, resembling grumous blood
It consists of a fine reticulum of fibers, continuous with those of the splenic trabeculae, to which are applied flat, branching cells.
The space of the red pulp is divided into cords of Billroth and sinusoids.
Cells found in red pulp
The meshes of the reticulum are filled with blood:
The white corpuscles are found to be in larger proportion than they are in ordinary blood.
Large rounded cells, termed splenic cells, are also seen; these are capable of ameboid movement, and often contain pigment and red-blood corpuscles in their interior.
The cells of the reticulum each possess a round or oval nucleus, and like the splenic cells, they may contain pigment granules in their cytoplasm; they do not stain deeply with carmine, and in this respect differ from the cells of the Malpighian bodies.
In the young spleen, giant cells may also be found, each containing numerous nuclei or one compound nucleus.
Nucleated red-blood corpuscles have also been found in the spleen of young animals.