For some reason, I always thought nipples grew back, but after researching it online, I guess they don’t.
It got me to thinking, what bodyparts do grow back? Obviously skin, but what else? I hear the liver regenerates, and recently scientists discovered certain neurons do too. What else? What other body parts can be destroyed and regrown later?
Well, obviously dicks grow back.
You missed hair.
Hair’s a body part, but it’s never really alive in the first place, right? I never mentioned that in my OP, but I don’t feel the same excitement with hair as I would, say, a kidney. Same thing applies to nails.
This is sort of related: Why do we only grow back teeth once?
Does that count as something that grows back?
I’m not really the ultimate arbiter of such matters, but I’ll say sure, why not.
Yay! I contributed!
First time for everything!
I’ll try not to make a habit out of it.
Fat
I recall reading some years ago that it was discovered that fingertips can grow back in small children; perfect scarless regeneration, at that.
They don’t grow back, as such.
We just have (in normal circumstances) two sets lined up ready to use - the first set is small (to fit a child’s mouth) and disposable (so decay doesn’t cause death before reproductive age)
So, we could splice shark DNA with humans and grow 3+ sets of teeth? OK that’s getting off-topic.
I want this!
Don’t bother brushing! Just close your eyes and concentrate- pow! New teeth.
Or, splice Megamouth shark DNA with certain females! Bam, think of the blowjob potential!
OK, I need to stop. You’re not helping Melon!
Only if you’re not Bill Gates!
You don’t know the power of the Dark Side of the Force!
But not in your teen years. I just checked. The end of my left thumb, which I hacked off w/ a saw @ 16 or 17 (accidentally), is still shorter than the right one, by the same amount I cut off.
Almost every section of every organ will grow back (or try its hardest, at least), provided the scaffolding (basement membrane, connective tissue) has not been destroyed. Skin layers, which are constantly being shed and replaced, are a good example.
But it is not as if you can take a chunk of skin and watch it grow scarless. If you that, chances are you’ve destroyed part of the scaffolding, and now the healing will leave a scar.
Liver is very good at regenerating, again if it doesn’t get too damaged. Bone itself is constantly being turned over. There are constant pieces being taken down and new bone being laid. Inside some bones, their bone marrow, which has precursors of most blood cells, remains active throughout life. It has to do that, you know, otherwise you’d die.
In contrast with bone, skeletal muscle takes longer to grow back because it has a more limited capacity. Neurons and cardiac muscle have an even more limited capacity, even if the scaffolding around them is intact.
My sister works for a biology research group which is studying limb regeneration in salamanders. They hope to one day apply the technology to humans.