After a long absence, we're back! With an episode about the autoimmune disease multiple sclerosis and how immune cells navigate the around the body.
We'll try to get some relevant graphics up soon, but for now, check out this video, which shows leukocytes (in white) rolling along the blood vessel walls. You'll have to take my word for it that there are actually thousands of those white cells flying through the field of view - you just can't see most of them because they're moving too fast. You can also check out the wikipedia page on "extravasation," which is a term we didn't mention specifically, but refers to cells leaving the blood stream and getting into tissues.
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