Hey everyone, thanks for tuning into Dnews Plus again today,
I’m Tracen, this is episode two of three on puberty.
We are talking about how humans start puberty and
then what happens.
Today is the what happens. And eventually we are gonna talk about
if we can reverse puberty and go backward,
it’s gonna be really cool.
Make sure you stick around, subscribe all that great stuff.
But first, what is puberty exactly?
Like, we know of it
as the thing that we went through when we were teenagers
if you past that stage.
If you’re not there yet,
stick with it, it’s gonna be awesome.
It’s gonna be terrible, but then it’s gonna be awesome.
Several factors come into play,
when we’re talking about puberty and when it takes place.
There’s the genetics of it, there’s environmental factors.
For most people, it begins between the ages of 11 and 16,
but there is a trend right now of it happening much earlier.
There are usually telltale signs of when it started.
Now I don’t know if your parents,
祖父母 老师 或者其他什么人
or your grandparents or your teachers or somebody,
has had a conversation about puberty with you.
But for me, it was…
you get hair in funny places and start liking girls.
That was what they told me in my Midwest small town.
But, hair and funny places is actually not the beginning of puberty,
that comes out later.
Pubic hair does not puberty mean.
It all starts up in the brain,
before pubic hair has even started.
We’re going into more depth on the chemistry of it in a minute,
but the first signs of puberty,
medically speaking, for girls,
are breast development, breast tissue development,
and for boys, are larger testicles and a scrotum
that begins to thin and redden.
Now if you’re feeling awkward about all this stuff,
I’m sorry but we have a…, you know,
medical show here, a little science things.
So after that, all hell breaks loose.
For females, typically they start at first,
they’ll get pubic hair, they have hair on their arms and legs.
The breasts start to grow,
nipples start to enlarge, they start their period.
It usually happens a little later than breast development.
Pubic hair becomes coarser and curlier,
the adrenal glands make male sex hormones
对 在女性体内分泌 她们也有睾丸酮素
inside of the body, yes in women, they also have testosterone,
the ovaries begin to produce estrogen,
the larynx has structural changes that changes the voice,
the armpit hair starts to show up, hair on the upper lip,
她们排汗增多 长痤疮 白头 黑头
they start to sweat more, you get acne, whiteheads, blackheads,
pus-filled spots called pustules.
另外还会长高 增重 拥有身材曲线
Plus you grow taller, you gain weight, you get more curvy,
all sorts of stuff.
For men, for males, very similar changes in some ways,
体毛浓密 排汗增多 胸部暂时会发育
you get hairier sweaty, or you even get breasts swelling temporarily,
acne, of course, pustules growth,
grow spurts. But they also experience wet dreams
as the sex organs start kind of working it out,
the enlargement of the larynx changes the voice,
vocal chords lengthen, the voice breaks,
and then gets permanently deeper,
you kind of fly back and forth over that throughout your life.
Testicles drop and the penis actually gets a little larger along with the seminal vesicles,
the prostate and the bulbourethral glands.
After the initial ejaculation,
guys are pretty much fertile, that’s that.
This process is pretty important,
because the whole point is again, turning an undeveloped sexually anyway,
human, into a developed sexual human,
you’re getting ready to breed.
We’re gonna come back to that,
but that’s pretty much what puberty is for.
The point is, before puberty,
sex doesn’t do anything even if you could have it.
After puberty, sex causes pregnancy
so that you can propagate the species.
How long this lovely process will take?
当然 因人而异了 对女性来说
Of course, varies. In females,
from the first indication of puberty,
that breast tissue development, to complete maturity,
can take anywhere from eighteen months to six years.
In males, it’s very similar sometime between
18 months to six years. But,
the male genitalia has been known to take
between two and five years to fully develop.
So if you are a male out there
and you are currently going through puberty,
don’t worry, it’s still going, still changes.
But as I said before, puberty actually doesn’t start out here,
with our visible distinctions,
it starts in the brain.
The trigger for puberty to begin
in both boys and girls is the production of a hormone,
gonadotropin-releasing hormone, GnRH.
It comes out of the hypothalamus,
and that little guy sends the pituitary gland into overdrive,
Pituitary gland is like the star of puberty,
if like, puberty were a concert,
pituitary gland is Justin Bieber,
people can’t get enough of puberty gland.
That little gland is releasing hormones
all over the place.
We got the follicle stimulating hormone,
I think you can probably guess what that does,
the luteinizing hormone.
Those hormones head to the testicles and the ovaries and they essentially
start setting things up, getting things ready.
Sexual maturity has begun.
I mean not exactly, again 18 months to 6 years later,
it’s gonna be done,
but it’s a long process.
Scientists don’t really know why or what
triggers the hypothalamus to suddenly start releasing this GnRH,
which is actually kind of crazy.
The maturing ovaries and testes will then also secrete
gonadal steroids and estrogen testosterone.
There must be some kind of countdown
that trips is what people figure
once you reach a certain age.
A study in the Postgraduate Medical Journal from 1975 found
that with age, the ganadostat
becomes progressively less sensitive
to the suppressive effects of sex steroids,
so let me translate for you.
Essentially, they thought that there was some hormone
that was restricting or holding back
the pituitary gland, you know,
this hormone was like the opening act
in the concert of puberty that we were just talking about.
It was keeping the Biebs off stage,
but at some point, Biebs got to get out
he’s got to get on that stage,
the crowd is sick at the opening act,
and that’s how they think.
You may have desensitized over time
to that blocking chemical
that allows your body to start becoming mature.
There’s also another theory that the hypothalamus,
the brain itself, parts of the brain weren’t mature enough yet,
and once they get to a certain maturity level,
they’ll start releasing hormones
that kick off the process.
So, maybe there’s a tipping point of gonadal steroid levels.
There are all these different guesses but,
it’s not like you can stick something into the brain and,
see what’s going on with the chemicals
in a prepubescent and post-pubescent kid, right?
Not really ethical. So this is our best guess.
In the end, all of these hormones start turning the keys,
all over our bodies and starting construction projects
including all sorts of other stuff,
which is why these changes don’t just affect us physically,
they also affect our behavior.
It’s hypothesized that these gonadal steroids
activate dormant neural circuits
that cause us to act more like an adult in a few different ways,
both socially and reproductively.
Animal studies show that sex steroid hormones
have three effects on behavior.
First, we start thinking about things
from a reproductive standpoint a lot more.
You know, you start noticing
the member of the sex that you’re attracted to,
and this occurs mainly in the hypothalamus.
Second, our sensory and association regions
start to get reorganized,
literally the brain starts to change its structure,
things like the visual cortex and the amygdala,
the hippocampus they start doing different things and,
so we start seeing and smelling people
as potential sexual partners in a different way than we did before.
And third, the reward areas of the brain get rewired.
This happens mostly in the nucleus accumbens
and the dopaminergic pathways to the prefrontal cortex.
Basically areas of the brain that make you want to get down with the hotties,
whoever those hotties happen to be,
brain chemistry is pretty crazy actually, if you think about it.
But again, the results of this are mostly from animal studies,
a lot of it was done postmortem and dissections after the fact,
they started taking these brains apart and saying
Woo! This brain looks different than that brain,
What’s different? Ahh, these chemicals there and there,
these chemicals there and this starts to make these changes.
So more research is obviously needed
and maybe someday we’ll be able to,
you know, put something in your body
that can tell us what’s going on, but as of now,
重申一次 是猜想 但有一点说得通
again, a lot of this is guesswork, but it makes sense
that we would first start liking people from a reproductive standpoint.
Second, start associating those people
and smells and sights with certain things,
and then get rewards when we are successful in sexual,
at least interest, not so much reproductive stuff early on,
because some of us are really awkward for most of our lives.
总之继续说 所以我们可以 并且已经研究了青春期的发展过程
Anyway moving on. So we can and have studied this development,
and there’s been some really interesting studies in grey matter,
in the brains of adolescence,
Several aspects of cortical gray matter
changed during development.
比如密度 厚度 以及体积
Things like density, thickness and volume.
Gray matter actually develops in this interesting inverted u-shape,
and it reaches its peak in adolescence.
Some believe that there’s a definite connection to puberty hormones,
and this gray matter development.
And what’s even crazier is that MRI scans during adolescence
show that the amygdala
which is like an emotional center of our brain,
the volume grew for males,
but it didn’t grow for females.
That’s super interesting, right?
The hippocampus also increased in volume for females, but not males.
The hippocampus is like a memory and association center.
It’s really interesting.
According to an assistant professor at John Hopkins Bloomberg School of Public Health,
named Sarah Johnson, because of the increase in the brain matter,
teens have the processing power and decision-making skills of an adult.
Given enough time, to process the situation and information.
So yes, teenagers are essentially young adults,
but it takes them longer,
to get to the same conclusion that an adult who is developed
would have gotten to.
Usually though, teens are overly influenced by their emotions,
because though their processing power is getting stronger,
their emotional power is also getting stronger.
And that brings us to the limbic system,
the amygdala which I just mentioned,
directly linked to a lot of things,
愤怒 恐惧 侵略性 激动 性吸引
rage, fear, aggression, excitement, sexual attraction,
and it makes sense that during this part of our lives,
puberty and adolescence and such,
teens experience all of those things, probably in about five minutes.
But when does puberty really end, right?
I know I said eighteen months to six years,
but according to the National Health Service in the UK,
most boys will have reached a full adult age by the age of eighteen.
Girls, also, about the age of eighteen.
So maybe there’s something to that,
once you’re 18, you’re an adult.
Although other studies have shown the brain doesn’t fully develop
until you’re in your 20s.
So it really depends.
Are you going… you’re physically an adult?
Or mentally an adult?
So I guess that’s a question I should pose to you,
so tell us down in the comments, what do you think?
Should we let people continue to be considered kids until their brains are developed?
Or is 18, when your puberty is over,
are you now an adult?
Let us know your thoughts in the comments,
make sure you subscribe so you get more episodes of dnews plus.
And now tomorrow, we’re going to figure out
after we learned all about this process,
if we can reverse it.
Can we go back? Can we regress? Find out tomorrow.
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