A former student of mine shared this wonderful little video with me at the end of summer session. Counter-current multiplication is the way the nephron reabsorbs Na+ ions and water in the loop of Henle to produce concentrated urine and minimize water loss. It is often a complex concept for students in my intro class to grasp (CB says it’s the hardest concept in the class), but this video is great for breaking it down into the basics. I’m going to keep this link handy to show future students who are having trouble understanding.
In other physiology news, there’s a great post up at WhizBANG on how excess salt causes bloat.
Also, if you are an LGBT scientist, you may want to head over to Biochemist in Training and answer her questions about how to be a better ally.