Things I wonder about bodily fluids:

1.  How much blood can you lose without dying?

2.  Suppose you're a hemophiliac, so if you start bleeding it doesn't stop without medical attention.  Suppose you get a really really tiny pinprick, so you're bleeding very very slowly.  If you're bleeding at a slower rate than your body can regenerate blood cells, but you keep bleeding forever, would you still bleed to death or could you keep functioning normally despite the fact that you're trickling blood.

3.  When people have had total kidney failure so they have to have dialysis, do they still need to urinate?