Scientists have discovered that the spleen, long consigned to the B-list of abdominal organs and known as much for its metaphoric as its physiological value, plays a more important role in the body’s defense system than anyone suspected.Reporting in the current issue of the journal Science, researchers from Massachusetts General Hospital and Harvard Medical School describe studies showing that the spleen is a reservoir for huge numbers of immune cells called monocytes, and that in the event of a serious trauma to the body like a heart attack, gashing wound or microbial invasion, the spleen will disgorge those monocyte multitudes into the bloodstream to tackle the crisis.“The parallel in military terms is a standing army,” said Matthias Nahrendorf, an author of the report. “You don’t want to have to recruit an entire fighting force from the ground up every time you need it.”

via Basics – Finally, the Spleen Gets Some Respect – NYTimes.com.