Why do nipples get hard when someone is cold?

Why do nipples get hard when someone is cold?

Same reason you get goosebumps?

And, how come your dick does the opposite?

Hmm. I was going to say “erectile tissue”, but Wikipedia says no with no further explanation. Anyone know?

Here’s more info but still nothing definitive.

Here’s more:

From: http://www.the-clitoris.com/f_html/fr_index.htm

(bolding mine)

If you click on the nipples link in that article, you get a whole article on nipples which says, in part:

These muscles are in place to cause the nipple to become erect during breastfeeding. As a side effect, cold also causes them to contract in a similar manner to the tiny muscles attached to your body hairs, which is what causes “goosebumps” in the cold. It is the contraction of these muscles which causes the nipple to become erect.

That’s what the second link in my first post leads to.

Isn’t that what my other post says??

But thank you all the same.

Yes, but obviously it wasn’t there when I was posting.

OK, My nipples are erect right now. Why is that? It’s not cold where I am.

I dunno. Quoting posts makes you horny? :smiley:

Makes me horny.

Heh heh heh…you said “nipples”. Heh heh m heh.

Oh. Right.

slinks away

Well, I’m not clear on exactly why temperature changes should affect the nipples, particlularly since I’ve noticed that MY nipples get hard when I’m in a very hot shower. What’s up with THAT? What is the mechanism that leads to that condition?

Probably stimulation in general does it.

As for the male bits, the scrotum shrinks when it’s cold as part of the temperature regulation system for the testicles. The testicles function best in a narrow range of temperatures, a little below body temperature (which is why they hang outside in the first place). When it’s hot out, they need to hang further from the body to be at that temperature, so the scrotum extends. When it’s cold, they need a little more body heat, so the scrotum contracts to pull them in. To the extent there’s any effect on the penis, it’s just going along for the ride.

Well, yes, but I guess I’m asking what the mechanism is. Stimulation leads to muscular contraction? And for what evolutionary purposes could this be? Perhaps it increases the sensitivity in females and makes them more inclined to engage in intercourse? I wonder. FWIW, I am a male. So whatever the mechanism and purpose, in me it evokes the old question of why men have nipples, and makes me think it’s one of those parallel constructions that males happen to carry but that is functional in females.

No, no, you’ve got to remember the other purpose of breasts, here. The primary cause of nipple stimulation would be a baby attempting to suckle. And that baby will have an easier time of it if he has a nice protruding nipple to latch his lips onto. So when the nipples are stimulated, they respond by becoming suitable for nursing. The reaction in males, of course, is just evolutionary sloppiness, like the existance of male nipples in the first place (it’s easier for an organism to exist with similar male and female structures).

Ah, yes. Suckling. That must be part of the story. But sexual arousal leads to erection as well. There might also be increased sensitivity to touch when nipples are erect, which would support my hypothesis - that nipple erections would tend to lead to continued sexual activity, e.g. intercourse.