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Wondrous Wednesday 15: Body Cell Regeneration

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Summary

"Body regenerates every 10 years" - not entirely true. Red blood cells: 4 months. Skin: 2-4 weeks. Hair: 6 years women, 3 years men. Liver: 150-500 days. Stomach/intestine lining: 5 days. Bones: 10 years (slows with age). BUT brain neurons generally don't regenerate (except smell processing areas). Brain connections change but cells stay same - this is probably why we feel like "same person."

Transcript

0:00 Welcome to ANI In The Air, Wondrous Wednesday, where I talk about something wondrous.
0:08 So I thought I'd briefly mention this thing that I've heard for decades, that basically
0:19 our bodies, human bodies, regenerate every 10 years.
0:24 So after 10 years, there's nothing left.
0:26 Now this is not entirely true, apparently.
0:30 What is true is various cells do regenerate themselves entirely.
0:38 So red blood cells live about four months, apparently.
0:45 And so after four months, they are totally rejuvenated.
0:51 No red blood cells from the past.
0:55 The skin is, you know, our outer layer of protection, and that gets rejuvenated every
1:03 two to four weeks, apparently.
1:05 So if you looked at yourself two months ago, you were looking at something entirely different.
1:12 All new skin being seen.
1:16 The hair, this probably needs a fact check, but supposedly has a lifespan of about six
1:25 years for women and three years for men.
1:28 I don't understand why there'd be a difference, but okay.
1:33 The liver is more on the order of a year, somewhere between 150 to 500 days.
1:40 It's the, you know, main detoxifier in a body.
1:44 And stomach and intestines, the outer lining is maybe only up to five days, so they're
1:52 dealing with lots of acid and stuff.
1:54 Harsh life.
1:56 Our bones apparently takes a full 10 years to regenerate, although that slows down as
2:06 we age.
2:07 So that's probably where the 10 years figure.
2:10 So that's a lot of major systems that do regenerate, and you know, it's, you know, that's a big
2:22 bulk of who we are, like literally.
2:27 However, the way we think of ourselves in terms of our mental states, I think therefore
2:34 I am, that is governed of course by our brain, at least in part.
2:44 And the neurons in the brain, they generally don't regenerate.
2:49 Apparently there are certain areas that do create new nerves, such as the place for dealing
3:02 with sensory smell information, seems oddly specific.
3:08 But for the most part, the configurations of our brain, while changing, is not changing
3:14 because of new cells, but just simply, you know, the neurons making connections or getting
3:24 rid of connections or whatever it is they do.
3:27 So yeah, that's my thought.
3:32 I wonder if spotty, I mean, you know, a lot of times people bring this up to say something
3:39 along the lines of, well, you're not the same person you were 10 years ago or 20 years ago
3:44 or something, it's a whole new individual.
3:48 And I think with the, you know, it's obviously a philosophical debate as to whether one thinks
3:54 that way or not, but I would say most people, if with the brains being kind of fixed, would
4:05 consider that kind of the same person, although obviously we're not the same, we change a
4:11 lot, but you know, the basic structure is still the same there.
4:17 But it is kind of like weird to think about just how much change is going on in everybody
4:23 you see, and yet you never see the change, right?
4:28 You don't see anyone really shedding skin other than, you know, some medical conditions.
4:36 And we all know that, you know, stuff grows and flakes off and whatever, and cells die
4:42 and get discarded, new ones grow, but I find it a little bit wondrous to just think about
4:50 that all going on and our mental awareness of it all is just kind of all put to the side.
4:57 It's like, eh, it's not really happening.
5:00 So I think that pretty much does it for Wondrous Wednesday.
5:07 Just a little bit of a brief notion of thought.
5:10 So the next time you see yourself or somebody else, just think about all that skin that's
5:15 going to be replaced in a month.
5:18 It's kind of crazy.
5:20 All right.
5:21 Well you all have a good one and see you when I see you.