Why, when every other essential organ is protected internally, are mens testicles on the outside?
WAG: to control the temperature. Testicals lower themselves when the sperm gets too hot - it is supposed to be cooler than standard body temperature.
I’m no biologist, just an end user of the product. YMMV.
Agree with Coldfire here. From what I remember from biology in school, sperm needs a lower temperature than normal body temperature to keep it alive and healthy. (AFAIK all mammals have them “hanging”.) That’s why tight clothing is actually bad for a man’s fertility: it keeps your testicles too warm…
Men’s testicles? Is there any other kind? 
It is to control temperature. It’s why doctors suggest boxers (where the boys hang free) as a way to increase the likelyhood of conception over briefs. Ever seen the Seinfeld “shrinkage” episode? It’s like a scared turtle!
And Coldfire…um…“end user?” :D:D [sub]I’m such a perv [/sub]
Most. Elephants, whales and seals are exceptions. They have other temperature regulation mechanism for their testicles which are internal.
It’s because they are SO much fun to play with!
Yes, but this just raises the question- why did we evolve so our sperm are that sensitive to temperature? Wouldn’t it have been better to evolve with sperm that thrived at 98.6, so inside the body was best?
Arjuna34
I suppose those people with undescended testicles all ended up dying off. Having an undescended testicle does make you more prone to having testicular cancer I thought.
Of course, that could have nothing to do with this topic.
If so, I will stick to answering questions about obscure football rules.
Alternate theory: testicles exist outside the body to allow Hollywood screenwriters to get cheap laughs.
Alternate theory number 2:
It’s so your dick can hang around all day complaining that his neighbors are two nuts and an asshole.
They were originally designed to be retractable in case of imminent danger, but somebody in quality control blew it and signed off on a schematic in which the control wires had been reallocated to other circuits.
Two cents more: the sperm become toooooo active at the normal body temps (as inside a female). Protection is enough by location. If it were not enogh, we all would develop something else, but as acute observers above noted, we all would have less fun.
OK, so why is it that one testicle (usually the right, I beleive) hangs lower than the other?
So that we can walk painlessly.
doooooooooooo your testes hang low?
Can they wobble to and fro?
Can you tie them in a knot?
Can you tie them in a bow?
Can you throw them over your shoulder,
like a continental soldier?
Do your testes hang low?