http://ask.metafilter.com/tags/hematopoiesis Questions tagged with 'hematopoiesis' at Ask MetaFilter. Wed, 07 Jun 2006 19:05:54 -0800 Wed, 07 Jun 2006 19:05:54 -0800 en-us http://blogs.law.harvard.edu/tech/rss 60 http://ask.metafilter.com/39748/Ahh%2DI%2Dhave%2Dblood BloodFilter: How do new blood cells make their way out of bones? Help this anatomy-challenged Mefite understand! This may seem like a silly question. But I've Googled like crazy, and I've still been unable to find anything that will explain in minute detail how exactly the blood cells created in humans' bone marrow make their way out of the bones.<br> <br> I've found the <a href="http://en.wikipedia.org/wiki/Haematopoiesis">Wikipedia stub about hematopoiesis</a>, but that only explains how blood cells are formed, not the path they take to get out of the bones.<br> <br> So how does it work? Do blood cells make their way out of "pores" or "channels" in the spongy part of the bone? That was the best guess my friends and I could come up with—but we don't know if it's correct. And even if it is correct, it still doesn't explain how the cells get into the bloodstream. Are there veins that directly abut the bone? If so, how do the blood cells move into the veins—do they somehow go through the blood vessel wall?<br> <br> I never took an anatomy class, and the only biology I had was eight years ago—I took physics courses in college. Please forgive my ignorance! tag:ask.metafilter.com,2006:site.39748 Wed, 07 Jun 2006 19:05:54 -0800 blood bloodstream bone hematopoiesis marrow resolved veins limeonaire