St. Patrick's Day is upon us! And while the Irish holiday has a veryÂ
rich cultural and religious history that  should be respected and at the forefrontÂ
of any celebration, it's also become a day  for many to let loose and enjoy themselvesÂ
an alcoholic beverage or two — or more... In today's video we're going to take a look at  the pathway alcohol takes asÂ
it travels through your body. We're going to see the various organs andÂ
tissues that it interacts with along that way,  and we're even going to discuss that "ohÂ
so wonderful" feeling called a hangover. There's a lot to do, so let's do this! First and foremost I have to getÂ
this out of the way — alcohol,  or more properly known asÂ
ethanol — is a legitimate toxin. While there are studies that have shown thatÂ
small amounts of daily alcohol consumption  can actually be good for you, those studiesÂ
are pretty inconsistent with each other and  you'd be hard-pressed to find anybody willingÂ
to say that alcohol is overall healthy for you. And this is not me judging you by theÂ
way. Personally, I am a bourbon man. It's one of my favorite ways to wind down. But there's never been a point as I'm sipping onÂ
the bourbon that the cells in my body are like,  "yes!! More toxic ethanol for us toÂ
detoxify and potentially get harmed from!!" But with that said if you areÂ
an adult of legal drinking age  and you're partaking responsibly,Â
all the power to you! I'm not gonna get in your way. Just know that it's not good for you. Okay? Okay! I'm glad we had this talk. To the cadavers! Obviously the very first place theÂ
alcohol is going to enter your body  is going to be the mouth or the oral cavity. And we can see that very thing right here. But this is a bisected headÂ
in the mid-sagittal plane. So that means that we've cutÂ
it right down the center. And that allows us to see a ton of really coolÂ
anatomy such as this gigantic tongue, the mandible  here, you can see the roof of the mouth, or theÂ
hard palate, and then the soft palate behind it. And then this little flappy thingÂ
is called the epiglottis and we'll  see that, or more what it does in just a second. But the thing to really understand is that liningÂ
the tongue, and lining the cheeks — in fact  lining the entire inner surface ofÂ
your oral cavity — is mucosal tissue. A mucosal lining that really just kindÂ
of helps keep things lubricated, and  just humid inside of your mouth. But the thing to understand is thatÂ
it's capable of absorbing alcohol. In fact they did a studyÂ
with some wine tasters to see  how much alcohol is getting absorbedÂ
when they're doing their wine tastings. Think about it — as they sip the wineÂ
they slosh it around, and spit it out,  they may not be drinking it but it's spending aÂ
considerable amount of time in their mouth and it  makes sense to figure out if some ofÂ
that's been absorbed in the bloodstream. And it turns out, a very small amountÂ
is — and I mean a very small amount. So that means when you're casually drinking,Â
a very extraordinarily small amount of  that alcohol is being directly absorbedÂ
into your bloodstream from your mouth. But the vast majority of it is going toÂ
continue on, and it's going to bypass  the tongue and enter this next areaÂ
called the pharynx or your throat. And that's where that epiglottis is goingÂ
to come down and block off the airway. This is the upper portion ofÂ
your trachea, or your windpipe,  and that makes this your voice box, or the larynx. And you obviously don't want the fluidÂ
going down into your airway, so the  epiglottis diverts it and pushes it into theÂ
esophagus — that's what you're looking at here. And the esophagus is your food tube, or I guessÂ
in this instance it'd be a food and a drink tube. In fact, I have anotherÂ
esophagus for us to look at here. Now this is going to look a little weird and beÂ
probably somewhat difficult to wrap your mind  around, but this portion — this is the larynx, orÂ
your voice box, and this is the "Adam's Apple". So that means you're looking atÂ
an anterior view of the trachea. This is the thyroid gland and thatÂ
makes this part of the tongue. But what we really want to focus on is — I'mÂ
going to slide the trachea, and that nerve  with with it to the side — andÂ
we see this is the esophagus. It's just a muscular tube that is connecting thatÂ
pharynx up here, all the way down to the stomach. So the stomach is actually going to beÂ
the very first real place that alcohol  is going to be absorbed into the body, and it'sÂ
somewhere around 10 — maybe 15 or so percent. The vast majority of alcohol is goingÂ
to get absorbed in the small intestine,  which we'll see in a second. But you can see on this stomach right here,Â
this — if I can hold this up properly — is  the end of the esophagus, andÂ
then it turns into the stomach. And it's just kind of curving over to the right. But this at the bottom — I guessÂ
I should say here at the base  of the stomach — we have this really importantÂ
structure called the pyloric sphincter. So this section of the stomach from here untilÂ
the small intestine starts is called the pylorus,  and inside of there is a very strongÂ
sphincter called the pyloric sphincter. And the reason why this sphincter is so important  is because it's literally a gatekeeperÂ
— that's what pylorus means. If you drink alcohol on an empty stomach, theÂ
pyloric sphincter is going to be more open  and the alcohol is going to justÂ
enter into the small intestine,  meaning that on an empty stomach alcohol isÂ
going to get into your bloodstream quicker. But if you have food or some other drink,  what's going to happen is inside the stomach aÂ
bunch of stomach acid is going to be secreted,  and this pyloric sphincter is actuallyÂ
going to pinch tight — pinch shut. And it'll slowly start opening it, kind of just  casually opens just a little bit here andÂ
there, and that's called gastric emptying. And it's at a very specific rate — wellÂ
more or less specific — and that means  if you have food with your alcohol, it's goingÂ
to get into your bloodstream, well — delayed. It's not going to happen right away. At least the majority of it. But like I said, some of the alcohol isÂ
capable of being absorbed in the stomach. In fact, I have a different stomach for us to lookÂ
at — which would be right here if I can get this  organized for you — and thisÂ
stomach has actually been cut. We've removed the pylorus, and that allows usÂ
to do this — this is one of my favorite things,  I love this — to reflect it like this. You can see the inside of the stomach. And you're looking at all these folds there,  those are called gastric rugae, andÂ
that literally means "stomach fold". They're just really uniqueÂ
and interesting to look at. What I want you to picture is thatÂ
this entire inside of the stomach is  also lined with mucosal tissue. And that mucosal tissueÂ
serves a variety of functions. One of the most important beingÂ
to actually secrete mucus. And that mucus prevents the stomach acid,  or that hydrochloric acid, fromÂ
consuming the stomach itself. It's kind of an important job. But the thing to understand is that the alcoholÂ
can be absorbed into that mucosal tissue,  and then from there it can get intoÂ
the bloodstream and head to the liver. So you can't — this, this is the entire reason why  if you take a drink, after just a coupleÂ
minutes you're gonna start to feel a rush. That's — even though the majority of the alcoholÂ
actually hasn't gotten into your bloodstream yet,  some of it has because it was absorbed throughÂ
the stomach here and then went to the liver. But the rest of it is actually — if I can pullÂ
this back — gonna go into your intestines. And I'm going to kind of bringÂ
them all over here... we're going  to see this a little more clearly inÂ
another cadaver section in a second. But this is where the vast majorityÂ
of your absorption is going to occur,  but that is going to take just aÂ
little bit more time to pull off. So let's go ahead and look at aÂ
different cadaver and finish our journey. Quick recap! When you first drink alcohol, it went into yourÂ
oral cavity or your mouth, some of it got absorbed  into the mucosal tissue and went directly intoÂ
your bloodstream, but it was a very small amount. You then swallowed it and it wentÂ
down your esophagus into your stomach. So the stomach on this cadaver here,  is going to be located — hopefullyÂ
you can see this — just like that. This is the stomach. And it's hiding behind this massive organ thatÂ
we'll talk about in a second called the liver. But what's going to happen, remember asÂ
it sends it into the small intestine,  the small intestine areÂ
going to do that absorbing. So the first place we can see the small intestine  coming out on this cadaverÂ
is going to be right here. Now as I move these small intestinesÂ
you're going to notice something's  different about it compared to the oneÂ
we just saw in that other dissection. The intestines are attached to your body. This is called the mesentery, and it's — the way I  always talk about it with my studentsÂ
is, I say — all those zombie movies? They're wrong. In the zombie movies you're getting like anÂ
abdominal wound, and the guts are just dragging. I mean it's possible — it's definitely possible. But that's a pretty serious cut. The intestines are attached and they need to beÂ
because what they do is they absorb the nutrients. But they have to absorb them toÂ
somewhere — bring them to somewhere. And if you look closely you're goingÂ
to see all these little blue lines. Those are veins taking whatever they'veÂ
absorbed — so this would be any food or  drink — any nutrients that went into theÂ
stomach and got released in the intestines,  is going to be absorbed into the mesentery,Â
and is then going to travel to the liver. The same goes for anythingÂ
that's absorbed by the stomach. And we did just see that alcohol, or ethanol, isÂ
absorbed in some quantity by the stomach itself. So the stomach and the mesentery in the intestinesÂ
are going to send the alcohol to the liver. And look how big this thing is! On top of it is the diaphragmÂ
muscle that I've scooted up so  we could get a pretty goodÂ
view of this liver here. It's absolutely enormous! This is the second largest organ in theÂ
body if you count the skin as an organ. And this thing is so amazing — itÂ
has so many different functions. But one of the coolest properties, I guessÂ
you could say of it, is that it regenerates. Most of your body does what's calledÂ
healing, and healing isn't all that cool. Healing is a mixture of someÂ
regeneration but mostly scarring. Not the liver — the liver isÂ
capable of true regeneration  and that's because it takes so much abuse. It's not just ethanol — there's other toxinsÂ
that get into your digestive tract that  it has to try and detoxify throughÂ
some really interesting chemistry. But throughout all that abuse it could take someÂ
damage, so it needs to be able to regenerate. Such an amazing organ! But let's take a step back again. So the alcohol goes into the liver andÂ
this is where it's going to be met with  an enzyme called alcohol dehydrogenase. But I should also mention the stomachÂ
also had alcohol dehydrogenase. What this enzyme does,  is it interacts with the ethanol and convertsÂ
it into something called acetaldehyde. Here's the ironic thing — acetaldehyde isÂ
actually more toxic than the ethanol itself. And if that's where it was leftÂ
then we'd have a serious problem. If — if — if we left just the acetaldehyde asÂ
it was — oh, you'd be in a world of trouble. But luckily the liver is also going to haveÂ
another enzyme that can convert that acetaldehyde  into something known as acetate, and the bodyÂ
can easily take care of acetate no problem. Here's the thing — the amount of alcohol youÂ
consume, and the time frame you consume it  has a pretty strong influence on the liver'sÂ
ability to convert it all the way into acetate. So what will happen is you drink it, itÂ
gets absorbed, it's permeating the tissues,  but it isn't able to handle theÂ
entire workload all at once. So some of that ethanol is gonnaÂ
make its way into the bloodstream. Because the liver is then gonna send theÂ
blood directly to the heart — and that's  what this gigantic thing is here, I'll kindÂ
of remove this — this is the pericardium. You can see the heart here, and what's goingÂ
to happen is the heart is then going to beat  and send that blood directlyÂ
to the lungs right next door. And this is how alcohol can be on your breath. Because as the ethanol gets in —Â
it's, remember it's in the blood,  but it's going to go to the lung tissue,  and inside of the lungs you have all these hollowÂ
air sacs that are surrounded in capillaries. And what will happen is the ethanol will evaporate  into those little air sacs, and then as youÂ
breathe out — so kind of picture if this could  inflate — and then as you breathe out and itÂ
kind of gets squished what's going to happen  is that ethanol is going to go up yourÂ
respiratory tract and it's on your breath. This is the entire premise behindÂ
a breathalyzer and why it works. So — kind of interesting that way — that you canÂ
actually get rid of alcohol when you are drinking. You're getting rid of alcoholÂ
by simply breathing it out. But not all of the ethanol is going to do that. The rest of it's going to go back to the heart  and then when that heart contractsÂ
it's going to send the blood  all the way up straight to the brain, and thenÂ
start distributing it throughout your entire body. And this is something that's so important to take  note of — ethanol is going to interactÂ
with pretty much everything in your body  except for bone tissue, becauseÂ
it's just so hard, and fatty tissue. Because you have to understandÂ
ethanol is water soluble  and fatty tissue is made of lipidsÂ
and oil and water do not mix. If you've ever done that experimentÂ
maybe back in elementary school. So sure — some ethanol can get into yourÂ
fatty tissue, but it's a very small amount. But everything else in your body...Â
so like I just said — your lungs...  I don't know if you'll be able toÂ
see this all that much — I'll kind  of pull this tissue to the side — there'sÂ
this organ down here called the spleen. Your gallbladder... everything in yourÂ
body is going to interact with the ethanol. To what degree does theÂ
ethanol have an effect on it? There's a lot of factors that go into it. It depends on how vascular that organÂ
and structure is in the first place. It depends on your genetics... itÂ
depends on your overall health. So it's hard to give you aÂ
real solid answer on that. But a real interesting one isÂ
what it does to muscle tissue. Actually I should probably take a quick step back. We're going to see the brain here inÂ
a second, but you need to understand  that ethanol actually stimulates what'sÂ
known as your sympathetic nervous system. This is your "Fight or Flight"Â
aspect of your nervous system. And what that means is it's goingÂ
to accelerate the heart rate. So the heart's going to just startÂ
beating, and as it starts beating  it's going to start pushing the blood evenÂ
more forcefully to things like muscles. It's also going to cause you to sweat. This is why if you're drinkingÂ
you'll start sweating because  your sympathetic nervous system is "going off". But think of all the ethanol that isÂ
hitting the skeletal muscle tissue. And that can actually have anÂ
effect on protein synthesis. So let's say you went to the gym earlier thatÂ
day and you got a really great workout in,  and then later that night youÂ
decided to have a few drinks. Well those drinks could possibly negate maybe notÂ
entirely but a significant portion of your gains,  because the alcohol prevents proteins fromÂ
being built inside of the muscle tissue. Absolutely fascinating what's going on there! So all right — alcohol is now —Â
if we kind of take a step back to  kind of make this kind of a process...Â
alcohol is now heading straight for the brain. So what we're going to do is we're going toÂ
jump on over to some brains and check it out. Okay! So blood is pumping straight toÂ
the brain and that's what we have here. So this upper portion is called the cerebrum, it'sÂ
highly folded and such an amazing structure — in  fact I did an entire video on just this oneÂ
section here called the prefrontal cortex,  so you should definitely goÂ
check that out after this video. This lower portion is called the cerebellum. But what we really want to look at because it's soÂ
cool, is if I flip it over, you can see that there  — if you look closely that is — there's this grayÂ
outer portion and then this white inner portion. This is gray and white matter respectively. The gray matter is where the cells of the brainÂ
called neurons are communicating with each other. So picture billions upon billionsÂ
of connections all happening in just  this tiny little area I'm traversing with theÂ
probe, and that's where they're just talking. And they talk with the use ofÂ
something called neurotransmitters. And I guarantee you've heardÂ
of neurotransmitters before. The two most famous areÂ
probably dopamine and serotonin,  but there's other ones like GABA and glutamate,Â
that ethanol is also going to affect. And ethanol is also going toÂ
affect the secretion of endorphins,  which — let's put this all together. So without getting too granular orÂ
nitty-gritty, you're gonna have pleasure,  you're gonna have euphoria, you'reÂ
gonna have lowered inhibitions,  and you're gonna have loweredÂ
cognitive ability and lowered reflexes. When you bundle it all together — soÂ
basically think about it like this... When you lower inhibitions, that's whenÂ
things you start start saying and doing things  that you normally wouldn't do. When you're drinking alcohol also you get thisÂ
great idea — "what if I took off my pants,  I jumped on the table, and i justÂ
screamed, I'm King of the World!" Anybody who's not drinking,Â
that is a terrible idea. But someone who's five shotsÂ
of tequila in, that's smart! Not only is it smart, it's necessary! That just goes to show your choice-makingÂ
ability has gone out the window. But you're literally thinking slower. You're also euphoric. You're happy about it! It's a really strange combination. But that is only the effect that it has on  the neurological tissue — it's alsoÂ
going to affect your hormonal system. So what I want to do is look at anotherÂ
dissection, and it's that sagittal head  that we've already seen, so we canÂ
focus on these two structures here. So this first one that I'm traversingÂ
with my probe is called the hypothalamus,  and this is going to be just above anotherÂ
really famous one known as the pituitary gland. Together they form what's known asÂ
the hypothalamic-pituitary axis. And that's a big word that's reallyÂ
not all that necessary to remember. Just understand that these two structuresÂ
control your entire hormonal system. The hypothalamus is more or lessÂ
in charge of the pituitary gland. So it'll secrete hormones thatÂ
boss around the pituitary gland. But the hypothalamus isÂ
constantly monitoring your body. So when you start drinking,Â
the hypothalamus is aware of it  and it's going to start adjustingÂ
based off of the ethanol. In fact it's going to basically tell the pituitaryÂ
gland to start bossing around your adrenal glands. And your adrenal glands are what secrete cortisol,  which is your stress hormone and epinephrineÂ
and norepinephrine — also known as adrenaline. So think about this... when you drink — not onlyÂ
do you have diminished choice making ability, your  inhibitions are gone, but now you're stressed andÂ
you have adrenaline coursing through your system. If you remember just a moment ago  we talked about the sympathetic nervous systemÂ
and the heart rate increasing and all that. So this is a pretty potent mixture. But not only that, the pituitary glandÂ
is also going to slow down its secretion  of a hormone known as anti-diuretic hormone. So a diuretic is somethingÂ
that causes you to urinate. So anti-diuretic hormone would meanÂ
that you would hold on to water. But what instead happens, is ethanol  influences the secretion of ADH, and that'sÂ
going to have a pretty big effect on your kidney. See the kidney is going to —Â
this is a really cool dissection. So you can see a bunch of amazing structuresÂ
in here, and these are just renal pyramids. And this outer portion is called the cortexÂ
of the kidney and inside of here are all these  tiny little filtration unitsÂ
that are filtering blood. You see, blood gets pumped — let's see if I can  grab this — through this arteryÂ
here called the renal artery. And that is then going to go to theÂ
outside of the kidney and get filtered into  urine, which will then be droppedÂ
down this long tube called the ureter,  and then the bladder, and then the outside world. That means your urine was once blood. Well — now, the ADH isn't beingÂ
secreted, the blood vessel — so  think about that — so another name for ADH,Â
or anti-diuretic hormone, is vasopressin. And I like that name because it soundsÂ
like you're pressing on blood vessels. Because that's what it'll do. It'll actually constrict the bloodÂ
vessels inside of the kidney,  meaning less blood volume is able to go andÂ
get filtered, meaning you make less urine. But if you're drinking alcohol what's gonna happenÂ
instead is you are going to be peeing a lot. I remember I used to — beforeÂ
I knew any of this years ago,  I used to be confused... like I'd have oneÂ
beer... like I'd try to do the math in my head. I'm like, "okay. I drank thatÂ
much... but I peed that much..." It never made any sense to me, butÂ
that's because of the lowered ADH. But what that means is youÂ
are now dehydrating yourself. You're getting rid of all this fluid — and more  fluid than you're bringing inÂ
through the alcoholic beverage. That also means the insideÂ
of here — without getting too  nitty-gritty into it — in order toÂ
make this whole process efficient,  the kidney is going to start droppingÂ
electrolytes into the urinary tract. And so that means as you urinate, you'reÂ
going to start losing electrolytes. And this is going to be kind of important when  we're talking about — or mayÂ
be important — with hangovers. But just think about it like this — not onlyÂ
are you dehydrated, you're also lowering your  ability to rehydrate because electrolytesÂ
are what attract water back into your body. So I'm sure you're starting to seeÂ
where this is all going... you're  jacked out of your mind onÂ
adrenaline and stress hormone...  you are making bad decisions, you're happyÂ
about it, and you gotta pee all the time! I mean, if that does not sum up theÂ
alcohol experience, I don't know what does! At the same time though, alcohol doesn't affectÂ
every single individual in the exact same way. There are certain things thatÂ
affect how it effects you. So for instance, sex is a large one. You see, females have aÂ
higher body fat percentage. And so let's say, I had a male andÂ
a female who weighed the exact same  and they drank the exact amountÂ
of same amount of alcohol. Well what would happen, sinceÂ
the female has a higher body fat  percentage, that also means sheÂ
actually has less blood volume. So that same amount of alcohol is moreÂ
concentrated in her lower blood volume  than it would be for the male, meaning itÂ
can actually affect her more intensely. But things like age are alsoÂ
going to play a giant role. You have things like genetics. There's certain people that just aren't ableÂ
to produce the enzymes in enough quantity  to properly break down alcohol. Like we mentioned earlier — do you have food inÂ
your stomach? Do you have drink in your stomach? These things are all goingÂ
to play a pretty big role. But we haven't even talked about what happens  after all of this... afterÂ
all the fun — the hangover. Hangovers are actually still pretty mysterious. We have general ideas, like I can tell you aÂ
hangover is essentially because you're dehydrated,  lack of sleep, just maybe physically beatÂ
up because who knows what you're doing...  like jumping on tables sayingÂ
you're the "King of the World". We can say like generally there's all theseÂ
little things that add up to create the hangover. But if you actually startÂ
trying to break down specific  pathophysiology — the real causes — it getsÂ
kind of hard to figure out what's going on. One of the leading culprits — at least what we  think — is that acetaldehydeÂ
that we mentioned earlier. So remember, acetaldehyde is moreÂ
toxic than the ethanol itself. And so the idea is that too much acetaldehydeÂ
can actually start to create that hangover,  or at least some of the symptoms of that hangover. Which I should probably mention the symptoms! I mean they're going to be things like —Â
and these are everybody's favorite, right? You've all been there. Diarrhea, nausea, possible vomiting,Â
just fatigue — you're just exhausted. And you have an extreme loss ofÂ
appetite, which is interesting because  if we're talking about how to overcomeÂ
the hangover, there's also not a lot of  real understanding as to whatÂ
can solve it other than time. I don't about know you, but I've heardÂ
probably every single remedy under the sun. I used to be in the United States Marine Corps,  and if any of you know about UnitedÂ
States Marines — we like to drink. And so I remember hearing so many differentÂ
remedies after a weekend of just harsh  inappropriate drinking. And my go-to was actually — please don't judgeÂ
me too harshly for this — my go-to was about as  greasy of a breakfast sandwich fromÂ
McDonald's as I could possibly get,  and then some kind of sportsÂ
drink like a Gatorade or Powerade. And I did that because someone told me that wouldÂ
fix it at some point, and I just kept on doing it. There's no evidence that thatÂ
actually helps all that much. Some people will say coffee. Some people say a shower. Sleep is obvious — that'sÂ
definitely going to help. But the only thing that's actuallyÂ
been proven, is time itself. You have to wait it out. If you if you're just dependingÂ
— there's no magic pill. Although, I am curious to see if you canÂ
leave it in the comments below what you may  have heard, or what you do, or what youÂ
swear by, because don't get me wrong — like  I still to this day, despite everything IÂ
know... if I do have a hangover, my first  inkling is I gotta go get some really grossÂ
breakfast sandwich, and that's gonna fix it. And what's funny is it neverÂ
does, but I keep doing it anyways. Again — please try not to judge me too harshly... Thanks for watching everyone! I had a blast filming this video,Â
but I wanted to take a moment  and just give my thanks to thoseÂ
who donate their body's to science. Because while I'm trying to make this lightheartedÂ
and fun so we can at least enjoy this,  I also want to be respectful and understandÂ
the amazing gift that they have given. Because without their generous gift, weÂ
wouldn't be able to show these types of things. What I often tell my studentsÂ
is — five minutes with a kidney,  or five minutes with any structure really, youÂ
learn more than in five hours in the classroom. Or maybe you learn something different thatÂ
you just couldn't learn in the classroom. And so as fun as we're having with this video,Â
it's nice to be able to see these structures  so you can better understand and hopefullyÂ
make better decisions with your drinking. Especially with St. Patrick's Day, or I don'tÂ
know — maybe it's Wednesday — for any of you. But again, I just wanted to extend my thanks  and gratitude to those whoÂ
donate their body's to science. But as always, please like, comment,Â
subscribe if you haven't already. Which if you haven't — what are you doing? We try to make videos like once a week. Sometimes twice a week. And if the stars align, we would love toÂ
push it to three to four videos per week. But make sure you hit that notification bell  so you'll be the first person toÂ
see the videos as they come out. But if you're gonna go drinkingÂ
please, do so responsibly. And try not to take your pants offÂ
and say you're King of the World... If you don't do that, as farÂ
as I'm concerned — it's a win.
That's a quality video., thank you.
https://www.reddit.com/r/neuronaut/comments/2v3342/brain_may_flush_out_toxins_during_sleep/
NrN Search 'ALCOHOL'
https://www.drugscience.org.uk/mdma-for-alcohol-use-disorder/