Cartilage would be your answer.
Our lymphatic systems act to drain lymph from our tissues, empties and redirects it back to the bloodstream. Therefore, blood vessels remove the venom which is to be drained by our lymphatic system, cycle repeats until no venom is left.
Land in the steam going down then to open water body and out to ocean or directly to ocean from stream.
Become evaporated, then rain down again
