The spleen is the largest lymphoid organ and is located in the upper far left part of the abdomen, behind the stomach and under the diaphragm. It is soft and purple, in the shape of a fist, and approximately 4 inches long. A healthy spleen weighs about six ounces, but when enlarged due to infection, can become enlarged and weigh up to four pounds. The spleen functions as a blood filter. It also stores white blood cells, recycles old red blood cells and platelets and filters blood in the immune system. The spleen also helps to protect the body against certain kinds of bacteria (Children’s, n.d). The functions of the spleen “are carried out by the 2 main compartments, the white pulp (including the marginal zone) and the red pulp, which are vastly different in their architecture, vascular organization, and cellular composition” (Cesta, 2006).

According to Velásquez-Lopera, Correa & García, “the spleen contains arterial vessels in which the smaller arterioles end in a sinusoidal system. The white pulp is formed by lymphoid sheaths with specialized T cells, B cells and marginal zones. The marginal zone is composed of fibroblasts, marginal-zone macrophages, B cells and dendritic cells (DCs), and it is the transit area for cells leaving the bloodstream and entering into the white pulp.” (2008). All types of cells are required to participate in the immune response for the spleen to function properly. “However, the frequency and distribution of cell populations able to modulate the immune response, such as DCs subsets and regulatory T lymphocytes, are not well established in human spleen” (Velásquez-Lopera, et al., 2008).

The spleen uses cell functions economically. Useful components from old cells, such as iron, are saved in the spleen, which then stores the iron and returns it to bone where hemoglobin is made. Hemoglobin transports oxygen from the lungs to other parts of the body (Children’s). Cesta, writes, “The spleen is surrounded by a capsule composed of dense fibrous tissue, elastic fibers, and smooth muscle with the outside layer of the splenic capsule made up of mesothelial cells” (2006). Spleen cells are unique in that cells in the body have different functions with each cell having a shape and size that allows it to do its job. Cells can combine to form muscle or body tissue and groups of cell types also make up our organs. Different cell groups in our bodies each have a different function and job to do (ScienceNet, n.d.). In other words, spleen cell groups are different than liver cell groups.

Useful components from old cells, such as iron, are saved in the spleen, which stores the iron and returns it to bone marrow. Always economical, your spleen saves any useful components from the old cells, such as iron. It stores iron in the form of ferritin or bilirubin, and eventually returns the iron to your bone marrow, where hemoglobin is made. Hemoglobin is an important protein in your blood that transports oxygen from your lungs to all the parts of your body that need it.

Tissue is comprised of related cells that while not identical, work together to accomplish a specific function. Each organ in our body performs a specific function and it is the combination of cell types that makes this happen (Villa-Forte, n.d.). Villa-Forte uses the eye as an example in that it “contains muscle cells that open and close the pupil, clear cells that make up the lens and cornea, cells that produce the fluid within the eye, cells that sense light, and nerve cells that conduct impulses to the brain.” (n.d.). Without the presence of one of these cell types, the overall function of the eye to work properly would not happen.

The spleen is a non-vital organ that has a specific and useful function even though most people are unaware of its importance.