“X bodily fluid is just filtered blood!” buddy I hate to break it to you but ALL of the fluids in your body are filtered blood. Your circulatory system is how water gets around your body. It all comes out of the blood (or lymph, which is just filtered blood).

“Okay but why is it always so chemically roundabout and unnecessarily complicated” well buddy, that’s because your blood is imitation seawater. See? It’s very simple.

Blood is what now?

It’s imitation seawater what part is confusing

#are you telling me#humans are just sentient aquariums? 

Buddy if anything is living in your blood (except for more parts of you) in detectable amounts then you have a serious microbial infection and need to go to the hospital.

Humans are seawater wastelands kept sterile of all but human cells, with microbial mats coating their surfaces.