this video is sponsored by brilliant find the link in the description below belly flops hurt and you don't need to have a ton of understanding in human anatomy to see why that's the case but what's fascinating about belly flops is what is occurring to the human anatomy as the body hits the water so in today's video with the use of the cadavers here in the lab we're going to take a look at the various organs and tissues and structures that are moving and slamming around inside of the body when you belly flop from maybe as little as a few feet or around a meter all the way up to 100 feet or around 30 meters it's going to be a painful one let's do this i actually want to talk about more than just belly flops because your body can be in other positions when it impacts the water and you can still get similar problems to a belly flop because the core of the problem or i guess the question we're pondering here is what happens when more surface area of your body comes into contact with the water and how important is the speed with which that occurs so i have a very simple science experiment for us to help illustrate this in front of you you have just under 300 milliliters of water and then we have a water bottle now there's some water in there but that's really not going to make too big of a difference here now as i place the water bottle in here you're going to all understand exactly what's going to happen because if you've ever taken a bath you've seen this happen firsthand right i can push this and we can see that i can raise the water level to 500 milliliters now i obviously didn't add 200 milliliters of water instead what's occurring here is water displacement the water is moving around the water bottle and to make room for it now this same thing has to occur when you're diving whether or not you're you have good form and you're cutting through the water efficiently or if you are belly flopping the water is still going to need to be displaced but to show you why the less surface area the better watch this we go to the same water bottle and we just turn it over and you see the cap here now as i put this in this is i don't know how well this is you're gonna be able to understand this at home but for me here as i'm doing this this is so easy compared to the other way around because less surface area is coming into contact with water and that actually makes the rest of the water bottles transition through the water much easier and it just essentially sinks it just goes right through the water we are cutting through the water there's also going to be less force being applied initially on the water bottle because there's less surface area coming into contact this makes a big difference if i just flip it over and do the same thing here i can feel this here as i'm doing this it's just much harder i mean i don't know about you but when i was younger maybe i still do this but when i was in the bathtub right i used to get my hand and i just place it on the water and you could feel the surface tension of the water as it's sticking to your hand but it's actually harder to push into the water that way than say if you just poked it right again that's all just going to be the force being applied in the opposite direction as you're hitting the water because as you displace the water let's go back here as you displace the water not only is the water moving around it's also applying a force back on the water bottle itself now if you go slow it's really not going to compromise the integrity of the water bottle all that much but if i just slammed this which i'm not going to do because i have expensive camera equipment right in front of me but if that was to happen well the water bottle might actually experience some integral integrity damage and the same thing would happen to your body now that's why again swimming form is so important right you're cutting through the water right the damage that can happen to the fingertips is still there the damage that can happen to the feet is still there but it's it's very much reduced in comparison to what's going to happen if you go this way or land on your back or something along those lines because not only you're gonna have to displace that water but you have to displace it fast depending on how high up you jumped right a belly flop from say just a few feet or around one meter right the speed with which you need to displace the water is going to be different than in comparison to say if you jumped from 100 feet or around 30 meters now obviously the skin is going to be the first thing to come into contact with the water after you jump which is why belly flopping tends to come with a lot of bruising and in fact that is the most common injury from belly flops and that's because to get more serious injuries you're going to have to be tripping from a lot higher distance than most people are willing to do but what we have here is going to be a skin dissection from the mid to upper back now i am touching the most superficial layer of your integumentary system which is just the anatomical way of saying skin plus fat and this layer that i'm touching is called the epidermis now the epidermis doesn't come with any direct blood supply it's what we call avascular so if i flip this over you can now see the underside of your integumentary system now this right here is going to be the dermis and the dermis is where we're first going to start seeing actual blood vessels but there are also going to be blood vessels going through this third layer down called the hypodermis so in order to get bruising you are going to have to rupture blood vessels now there are different blood vessels you can have arteries which arteries take blood away from the heart typically the blood is oxygenated but not always then you have capillaries capillaries are the exchange vessel meaning that's where nutrients and waste from cells are actually going to switch spots it's a very important blood vessel and then you also have veins and veins are going to take blood back towards the heart again almost always deoxygenated but not always the case in terms of bruising depending on how serious the bruise is you may be rupturing capillaries or possibly even veins or even their smaller counterpart called the venule but you can kind of picture that right if you smack the water maybe i should flip this over let's say you smack the water really ridiculously hard and as you do that that pressure is going to cause the blood vessels underneath to rupture and what will happen is the blood will start spilling over now depending on how the blood spills we will actually call it a different type of bruise because a bruise's real name is a contusion but you can also loop in some other types of bruises into it one of those is called a hematoma a hematoma is a blood-filled swelling and it typically is going to happen in multiple dimensions or three dimensions i should say so you'll actually get this raised swelling so if you had a lot of blood pooling in that skin and then there's this raised part to it we would call that a hematoma another type of bruise is called echimosis in ecchimosis it's going to typically stay flat so you're not going to see this raised area filled with blood but you can see the blood invading the surrounding tissues again that really just comes down to how many of the blood vessels and the type of blood vessel that ruptured during your fall the first thing i want to discuss when it comes to more serious injuries from belly flopping is going to be sprains and strains now a lot of times people will use those terms interchangeably but they actually mean something specific so right in front of you we have a right knee i can kind of rotate it around so you can see everything here this is going to be the posterior side then we have the medial side the anterior side and then that lateral side now a sprain is actually going to affect ligaments so right here on this lateral side i can stick my probe underneath it we have what's called the lateral collateral ligament also known as the lcl now its job is actually to connect the femur down to the fibula and prevent excessive range of motion so this isn't going to work or i don't want it to work but if i try to like spend and separate the fibula from the femur that would actually put stress here on that lcl its job is to resist that action ligaments define the range of motion in a joint they say yes you can you can go this far no you can't go that far if you injure a ligament by over stretching it that is called a sprain with a p however if you affect muscle muscle tissue or tendonous tissue it's right here this is called the quadriceps tendon and this is where all four of the quadricep muscles would actually blend into this tendon here and then connect to the patella or what most people would call the kneecap well if you injure the muscle tissue or the tendonis tissue here we call that a strain with a t now these injuries can be grade one all through all the way through grade three and that's just saying how severe is it grade three is a full on rupture grade one is just small little tears but you can just picture it right if you land in the water and you hit your knee depending on how you hit it you could actually create a strain and affect the tendinous tissue or the muscle tissue or you could sprain yourself and affect the ligamentous tissue and again it could be a full-on rupture or it could just be similar to like rolling your knee rolling your ankle those types of things are going to be more minimal sprain or strain but either way landing on joints is never going to be a good thing next on the list are traumatic brain injuries or tbis now there are many different types of tbis out there so i'm only going to focus on the few that are most commonly occurring with excessive belly flopping the first is probably no surprise to you and that is a concussion so you're looking at a human cerebrum here and you're probably going to notice that there's this incision that's been made along here this accidentally happened during the dissection process but the rest of the brain looks really really good now in a concussion this can happen a few different ways but probably the one that you're most familiar with is the brain can literally just slam into the skull right there's a fluid barrier that the brain is floating in but if you hit the head hard enough it can exceed that fluid barrier and literally come into contact with the skull and depending on which area the brain slams into the skull that can create different symptomology but another way a concussion can occur is actually due to rotational forces so this actually happens very frequently with fighters if someone gets punched or kicked in the head well we used to think that the brain was just slamming against the skull but what we're now starting to realize is that as the brain is rotating you have to understand and this is just physics in action that the outside of the brain is actually rotating faster than the inside of the brain as it's spinning and what that difference in rotational speed can do to the structures is cause sometimes separation or at bare minimum damage to these structures and this can create the symptomology of a concussion now another type of tbi that can occur is what's called a diffuse axonal injury and this is more of a shearing force so if you hit the head in just the right way some of the structures can continue moving forward while others are stopped and you can get a separation that way think the neurons of the brain which again you can't see that because neurons are microscopic but i'm touching the surface of the brain these cells here are what we call gray matter but parts of the grain of the cells are actually wrapped in fat and we call that white matter well if the gray matter separates from the white matter or what there's you can't see it in this dissection but there are large white matter tracts and pathways traveling through the brain that can literally get sheared off or start to separate and that can create a big communication issue within the neurological tissue of the brain and then the last tbi that i want to talk about is one that's probably going to make a lot of sense to you and that is brain hemorrhaging and you can see a lot of the blood vessels here on the surface of the brain now these blood vessels if they rupture that is going to deprive blood to areas of the brain or possibly blood returning from the brain tissue but if you have brain bleeds that is going to be a pretty serious issue the next thing on our list is probably going to make a ton of sense to you and it's also going to lead us directly into the last thing on our list and next up is bone fractures so what i have for you now is going to be the anterior aspect of the rib cage and if you look closely you're going to notice that there are some broken ribs here now this happened just due to handling over around the 10 or so years that we've had this cadaver the tissues just naturally wore down and broke but it's also important to note that it ripped or broke in the cartilaginous aspect of the rib where it blends with the sternum but i think everyone understands if you were to do a pretty serious belly flop that you could break or fracture your ribs but you could also fracture all the other bones in your body you could break your leg you could break your arm you could fill in the blank break your back all of that is up for grabs but if we think about it when a bone breaks it breaks into things it goes places so if you break your femur you could be shearing blood vessels if you break your back you could be paralyzed because it could sever the spinal cord and if you break a rib it could and i'm going to go ahead and remove this now puncture some of the internal organs in your body right so maybe it punctures a lung maybe it punctures the heart maybe it punctures the liver broken bones are not a good thing ever but you definitely don't want to have a broken bone if you have just jumped into a massive amount of water and it's now puncturing some of your organs which leads us to the last thing on our list and that's just overall internal organ damage now these organs can be injured in a variety of different ways from a belly flop maybe they slam into the musculature and bones of the rib cage and abdomen maybe they slam into one another because remember as they momentum is going to be conserved the moment they're going to still be moving forward as you hit and so they can definitely start slamming into things all over the place and when they do that they can start breaking you can picture the liver here just rupturing and fracturing you could picture the lungs picture this actually let's say you take a nice big deep breath and these things are just filled all the way to the max and then when you hit the water there's no give in the lung anymore that can cause some pretty intense collapsing of the lung which is one reason why it's actually a better idea if you're to dive to not take this crazy maximal breath instead you're going to want to take more along the lines of a half breath because that'll give give to the lungs so that they don't completely collapse but just fill in the blank here i mean any of these organs and structures can start rupturing and fracturing causing internal bleeding that can cause you a lot of problems real quick and in a hurry so i don't think it comes as a surprise to anybody that it's really not a good idea to do a belly flop but it's definitely not a good idea to do a belly flop from really high up probably realized this already but there was just no way i could do this video without sprinkling in some basic physics all throughout and that just goes to show how important physics is to the other scientific disciplines there's no way that you could understand biology without also understanding some basic physics you couldn't understand biology without some basic chemistry i mean how important is mathematics to the universe it is the universe and that's why i'm so excited about the sponsor of today's video brilliant brilliant is an awesome tool for learning stem interactively that is math science logic and computer science what i love about brilliant is they understand that if you really want to know something you really want to learn something and have it stick in the brain you need to make it fun and interactive but also relatable and that's one of the biggest problems with learning stem subjects in a university type environment it just tends to be dry and boring a lot of the time but that's not the case with brilliant take their course everyday math for example it provides you with foundational math lessons to help you get started on your stem journey without overwhelming you with mathematical abstractions and just exhausting the mind while you're desperately trying to take notes and hoping that you're comprehending what you're seeing it's an absolutely pun intended here brilliant way to teach math if you're interested go ahead and visit brilliant.org iha or you just click the link in the description below and the first 200 people there will get 20 off their annual subscription thanks for watching everybody i really hope you enjoyed this video and i will see you next time you