As we all know, the spleen has a number of functions including acting as a blood reservoir and as a site of lymphocyte development and activity. Research published a few months ago has now expanded our understanding of this odd organ.
According to the new research, another function of the spleen is to serve as a reservoir of monocytes that can be called upon during tissue injury in other locations of the body. The splenic monocytes, which far outnumber the monocytes circulating in the bloodstream, form clusters in the cords of red pulp just under the capsule (wall of the organ). From there, they move in a group out of the spleen and to the site of injury. There they help remove and repair damaged tissue.
You can use it in your course.
Want to know more?
Identification of Splenic Reservoir Monocytes and Their Deployments to Inflammatory Sites
Swirski, F. K. et al.
Science 31 July 2009: Vol. 325, no. 5940, pp. 612-616
[The original research article. A particularly clear abstract.]
Dispensible But Not Irrelevant
Jia T. et al.
Science 31 July 2009: Vol. 325. no. 5940, pp. 549 - 550
[Editor's summary of the implications of the original research. Full text version includes a great diagram of this newly discovered role of the spleen.]
Finally, the Spleen Gets Some Respect
The New York Times 3 August 2009
[Article summarizing the new findings.]
While we're on the subject of the spleen, have you seen the images of a pelvic spleen published recently in the New England Journal of Medicine? The piece in the NEJM briefly documents the case of a rare condition in which the spleen my drop into the pelvic cavity when there is problem with the suspensory ligaments of the spleen.
Pelvic Spleen: Images in Clinical MedicineFor a few FREE images of the spleen, go to the Lymphatic Image Library at The A&P Professor website
Tseng and Chou
New England Journal of Medicine 361 (13): 1291, Figure 1
[Images. Includes link to FREE PowerPoint slide for subscribers]