Monday, October 26, 2009

Revisiting the spleen

I'll never forget that snowy day all those years ago when my friend Keith slammed his sled into a laundry pole and ruptured his spleen.  Perhaps as an expression of our shock and concern for him as he lay in his hospital bed after his splenectomy, we spent an afternoon wondering to each other, "what IS a spleen . . . and how can you live without one?" 

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. 

This is a FREE image (click for source).
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
DOI: 10.1126/science.1175202
[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
DOI: 10.1126/science.1178329

[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
N. Angier
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 Medicine
Tseng and Chou
New England Journal of Medicine 361 (13): 1291, Figure 1
[Images.  Includes link to FREE PowerPoint slide for subscribers]

 For a few FREE images of the spleen, go to the Lymphatic Image Library at The A&P Professor website


Amber said...

I am an undecided student planning on pursuing a career in either the medical or Biology education field. I am captivated by the human body and have mentored in the Pathology department and emergency room at a nearby hospital. While in histology, I saw several spleens mainly removed because of cancer or fear of malignancy in tumors. I also questioned why we could live without what seamed like a vital organ.

Kevin Patton said...

Hey Amber, thanks for the information. I didn't realize that cancer was one of the reasons that spleens are removed, but it makes sense, right?

If you're thinking about biology education, you might want to consider teaching A&P! There's an increasing need for more of us, that's for sure. Check out for a good place to get advice and be mentored.

Amber said...
This comment has been removed by the author.
Amber said...

I was shocked at how many different organs were removed daily because of cancer.

I actually want to teach Human A&P more than Biology. Im fascinated by anatomy. Thank you so much for the Society's website!

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