By learning a bit more about 11 of these body fluids, we can develop a deeper appreciation for the beauty and complexity of our own biology. What exactly are these fluids, and what often unheralded contributions do they make?

A short list of bodily fluids includes:

• Blood. Blood plays a major role in the body’s defense against infection by carrying waste away from our cells and flushing them out of the body in urine, feces, and sweat.
• Saliva.
• Semen.
• Vaginal fluids.
• Mucus.
• Urine.

Biological fluids include blood, urine, semen (seminal fluid), vaginal secretions, cerebrospinal fluid (CSF), synovial fluid, pleural fluid (pleural lavage), pericardial fluid, peritoneal fluid, amniotic fluid, saliva, nasal fluid, otic fluid, gastric fluid, breast milk, as well as cell culture supernatants.

Modern medicine still bases healing on bodily fluids: blood, mucus, feces, saliva, semen, sweat, tears, urine, and even ear wax contain valuable information about a person’s health.

Potentially infectious blood and body fluids include

• fluids containing visible blood.
• semen.
• vaginal secretions.
• cerebrospinal fluid.
• synovial fluid, pleural fluid.
• peritoneal fluid.
• pericardial fluid.
• amniotic fluid.

Blood and body fluids, such as saliva, semen and vaginal fluid, can contain viruses that can be passed on to other people. If you have contact with a person’s blood or body fluids you could be at risk of HIV, hepatitis B or hepatitis C, or other blood borne illnesses.

URINE is sterile because it contains no living organisms, unless the person that produces is unlucky enough to have a urinary tract or bladder infection. There are less bacteria in urine than in tap water, for example. But drinking tap water is (generally) safe because it contains no toxic substances.

“Urine is actually not sterile,” said urologist Dr Rahul Rindani from South Coast Urology in Wollongong, NSW. “Urine has bacteria in it but it is difficult to detect unless you actually have an infection and have symptoms of an infection. And having an infection is very different to having some bacteria in your urine.”

If you let your pee sit around for a long while (I don’t recommend doing this, for obvious reasons), it will precipitate out an odorless fertilizer called struvite. So if you add a lot of urine to a lake, you’re essentially dumping in a bunch of fertilizer, which cases a bloom of algae.

Like you, fish have kidneys. Kidneys help the body make urine. The shape and size of kidneys can be different depending on the species. A lot of fish get rid of the pee through an tiny opening, called a pore, that’s near their rear ends—and in some fish, waste also goes out through the skin or the gills.

For those questioning whether or not human urine could be responsible for fish death, the answer is yes. According to i09, the phosphates in human urine act like a fertilizer that can promote algae growth. Algae blooms deplete the oxygen available to fish, causing them to suffocate.

Unfortunately, in the real world treating a jellyfish sting by urinating on it may actually cause someone in Monica’s situation even more pain, rather than relief. Urine can actually aggravate the jellyfish’s stingers into releasing more venom. Cnidocytes are spread along the entire length of the jellyfish’s tentacles.