The spleen is an organ in the upper left abdomen, which filters blood, disposes of worn-out red blood cells, and provides a 'reserve supply' of blood. It contains both red tissue, and white lymphatic tissue. The major (encapsulated) lymphatic organs are the lymph nodes, thymus and spleen.
Place the brined corned beef in a large pot or Dutch oven along with the liquid and spices that accompanied it in the package. Pour in enough water to cover the beef, then bring the water to a boil on the stovetop. Reduce the heat to a simmer, and cover the pot. A three-pound corned beef could take three hours or more to become perfectly tender. Check the meat occasionally, adding more water if necessary. The beef is ready when it pulls apart easily.
By convention, the beef chuck is separated from the rib primal between the 5th and 6th ribs. What this means is that it also contains a few inches of the longissimus dorsi muscle, which is the same tender muscle from which ribeye steaks are made.Note also that each side of beef has two shanks, one in the forequarter and one in the hindquarter.) Beef shank is used in making the luxurious Italian dish osso buco. That's it for the forequarter. Next let's look at the beef primal cuts that come from the hindquarter.