Each kidney tube loops back and touches its own filter. Right at that spot, a crowd of cells checks how much salt is flowing past.
Drag to turn it around. Use the buttons to zoom in and try things from the lessons.
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After the U-shaped loop, each kidney tube comes back up and touches the blood vessels of its own filter.
Right where it touches, the tube wall has a patch of tall, skinny cells squeezed close together. This patch is the macula densa.
Macula densa means dense spot in Latin. The cells are packed so tightly that their nuclei look crowded under a microscope!
It is like a feedback loop, checking and adjusting all day long.
Press Sense the salt on the 3D model, then press Send a signal.
By Operation Ouch. A fun video for kids.
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