How Bone Marrow Keeps You Alive

this video is sponsored by brilliant find the link in the description below bones are some of the coolest structures in the human body they provide structure support and protect your vital organs but even despite all of that bones still don't get the credit that they deserve and that's because bones provide even more functions that are essential for your health wellness and frankly for you to stay alive now these functions can't actually be seen on the outside of the skeleton we're going to have to go to the inside of bone to discuss this further and that's exactly what we're going to do in this video look at the inside of real human bone tissue where we're going to see structure and architecture that rivals anything us humans have ever created as well as see a tissue inside that is essential for you to stay alive so let's do this so as you can see i have two skeletons behind me jeffrey the skeleton as well as cornelius the skeleton now each of these guys wanted me to be extremely clear about how they were introduced jeffrey wants all of you to know that he is an all-natural real human skeleton as opposed to his sibling here that's a fake plastic skeleton now to be fair to cornelius he doesn't describe himself that way he wants all of you to know that he is a perfect synthetic replica of a human skeleton the sibling rivalry never ends unfortunately for cornelius we've got to use a real skeleton because we're going inside the bone so time for the role of shame don't worry your time will come all skeletal sibling rivalry and joking aside we're extremely lucky to have a real human skeleton in our lab so let's use jeffrey and his bones to talk about a few key points as we move to the inside of bone tissue so if we were to look at the outside surface of all of jeffree's bones of my bones and your bones and if i zoom in so i can actually touch the outside surface of a bone the outside surface is referred to as compact bone and if you were to look at like a textbook definition of compact bone it would say something like the dense outer portion of all of your bones now we refer to density because there's another type of bone tissue deep or underneath compact bone which is less dense and we'll talk about that bone tissue soon enough but compact bone even though it's the more dense version of bone tissue its thickness can still vary dramatically throughout the skeleton especially when we talk about the long bones of the skeleton which make up the majority of your limb bones like your humerus or where we've zoomed in to the femur down here now the end of a long bone is referred to as the epiphysis now the reason i brought up that fancy pants name the epiphysis or the end of the long bone is because at the ends or at the epiphysis the compact bone is paper thin so not very thick but when we compare that to the shaft of a long bone which is referred to as the diaphysis the compact bone gets much much thicker which makes sense so it can deal with the forces throughout the shaft of that bump but i can't show you the thickness on jeffrey because we haven't cut into that bone but we have another dissection here that i want to show you so this is a lower leg dissection and this is your shin bone that we truly refer to as the tibia and i'm touching the compact bone again that outside surface of the bone now a quick little reference here you can see a difference from here to there this tissue is called periosteum and i had to remove it from the compact bone periosteum is a dense irregular connective tissue that wraps the outside of your compact bone it's a really cool tissue it has blood vessels nerve endings and even bone cells in there that can help maintain the outside surface of the bone just for regular maintenance or even if there's damage like a fracture now speaking of a fracture if any of you have ever had a fracture or a bone break you'll tear and damage the periosteum and remember just kind of a cool fyi the periosteum had nerve endings or even pain receptors in there so when you break that bone and also tear the periosteum that periosteum is responsible for a lot of that pain you feel with bone damage so if you've ever broken a bone throw that in the comments let us know what type of bone break you've had because i'm sure some of you had some crazy ones but back to the compact bone here what you can see right here is we cut a hole inside there and if i roll it towards the camera there you might get an idea that is definitely thicker than just the paper thin compact bone that we found at the ends of the bones and i'll show you another dissection in a second that'll show that even better but this dissection shows you how cool the long bone shaft is because it's actually even though the outside even though the outside of it is thicker the whole shaft is still hollow and that hollow tube that i'm sticking the probe in there that you can see is called the medullary cavity now the medullary cavity we kind of refer to it as doing two things one it helps reduce the weight of the bone you don't need to have compact bone just fully full thickness throughout the whole length of the shaft so it does reduce the weight but also you see something inside called yellow bone marrow now this particular section of the lower leg doesn't have any yellow bone marrow in it because we removed it from the tibia but when i first did make this hole there was definitely yellow bone marrow that came out but i do have another dissection that we'll take a look at a cut through the upper limb and we're going to look down into the humerus to take a look at this yellow bone room so let's trade the sections here and if you take a look here we've got a cross section through the upper limb here now as you can see the compact bone you can definitely see the thickness of that shaft but that soft yellowy tissue inside that i've got the probe in here is the actual yellow bone marrow now yellow bone marrow is just another form of adipose tissue adipose just meaning fat so energy storage and we have a lot of different places for energy storage now some of you may have even eaten yellow bone marrow well not on humans because that would be weird but from other animals and i've never had it but i've heard some people really like it and you can throw that in the comments below if you like it and tell us what it tastes like but as far as this essential function yes we need energy storage but is that what i was referring to at the beginning of the video when i was talking about some of these functions that are essential for life and for you to stay alive no that we're going to have to take a look at another portion of the inside of bone and we're going to use jeffrey's femur here to zoom in and take a look at that so in order for us to go deeper to the inside of bone tissue we're going to take a look at the back side of jeffrey's thigh bone or for you anatomy geeks that would be the posterior aspect of the head of the femur now this isn't going to take very much for us to get to the deeper bone layer or the deeper bone tissue because remember the ends or the epiphysis of long bones that compact bone was only paper thin and if you look right above my finger there you can see some of that compact bone is missing now even this zoomed in angle that we have here still doesn't do the inside of your bones justice so we're going to zoom in even further right to the spot look at how amazing this deeper bone tissue is obviously this is going to be deep to the compact bone and this deeper bone tissue is referred to as spongy bone now it kind of makes sense if you look at it more porous and kind of resembles a sponge now those little beams of bone that are making up the spongy bone they would continue deeper into the bone tissue it's just we're so zoomed in right now that it's hard to bring those into focus but if i adjust the camera settings and you kind of look in the background there you should see those other little beams come into focus and that's pretty amazing to see that and let me come back into the original picture here now you've heard me mention the phrase little beams a few times so we should probably talk about these little structures in some more detail so these little beams of bone are actually referred to as trabeculae trabeculae translates to weird little beams now at first glance the trabeculae might look like they're oriented in all sorts of random directions but remember at the beginning of the video i said we're going to look at some amazing structures and architecture the trabeculae are not oriented randomly they are actually precisely oriented in the direct lines of stress that your bones experience on a day-to-day basis and they can even build up in change throughout life based on activity and even disease states like for example when you go from a little tiny baby not moving to crawling up to walking and running the trabeculae will build up in change based on the forces that the body experiences based on those different movement patterns of no movement to crawling to walking and running around like a little crazy toddler but we also need to talk about the spaces in between the trabeculae found in the spaces between your trabeculae is something extremely important to multiple body functions and that is red bone marrow that's a bit different from the yellow bone marrow that we talked about earlier which is another form of adipose tissue but your red bone marrow produces your blood cells now we say that the red bone marrow produces three different lines or three different types of blood cells let's start with the first being the red blood cells also known as erythrocytes eryth just means red sight means cell we also have the white blood cells or the leukocytes produced in the red bone marrow luke just means white against site meaning cell and the third would be the platelets which are also known as thrombocytes thromb just means clot and if we look at the functions of these cells we can see how vitally important red bone marrow is erythrocytes or red blood cells they're designed to carry oxygen to all the tissues throughout the body and everything about these cells is designed to carry oxygen the shape the hemoglobin inside these are actually some few cells in the human body that actually even get rid of the nucleus because they want more room to carry as much oxygen as possible the white blood cells we can all agree are pretty important because they are involved in immunity for things like fighting off infections tissue repair so again vitally important to our health and well-being the third cell line we mentioned were platelets or thrombocytes thrombogen meant clot so these are going to get involved in clotting your blood so say like you get a cut on your arm these are the cells that get in form the clot and stop the bleeding so again bone marrow being so vitally important because of the production of these different cell types now one thing we have to mention about this is i kind of want people to think about bone tissue sometimes gets thought of as dead tissue i don't know why i just have noticed that amongst my students it's probably because the bones tend to remain long after somebody passes away we use them at halloween but bone tissues are very much alive and as we mentioned are constantly changing and modifying throughout life so this spongy bone has an extremely important function not only to deal with stresses and strains that our bones experience but also to protect that red bone marrow and one thing we also have to think about where do we want all these blood cells all of these blood cells have to circulate throughout the bloodstream throughout the entire body so it's kind of cool to think about is that the bones have to have little holes or passageways for blood vessels to pass in run through those spaces of the red bone marrow pick up those blood cells and then take them out of the bone so they can distribute throughout the whole body now just keep in mind as the blood does go into the bone it'll also distribute nutrients so the bone can stay alive as well as pick up all of those different blood cells and one last thing i want to mention you actually will not find red bone marrow in the spongy bone throughout the entire skeleton you'll actually only find it in the spongy bone of specific bones in the adult those would be the sternum in the rib cage you'll also find red bone marrow in the spine or what we also refer to as the vertebral column also it's in the hip bones and the proximal ends of the humerus and the femur so what's filling the spongy bone in all of the other regions well that would be some more yellow bone marrow because who doesn't love to store a little bit of extra fat so there was our deep dive into the depths of your bones and hopefully you guys learned something new and interesting and speaking of learning if you haven't noticed we at the institute of human anatomy might be what you would call a little bit geeky because we love learning new things all of the time and that's why we love associating with those who also promote education and lifelong learning it benefits us as well as our viewers and that's why i want to say thank you to the sponsor of this video brilliant brilliant is an interactive online learning platform for stem subjects those subjects would be math science logic and computer science brilliant is constantly pushing the envelope of learning and education by creating new courses that are challenging but also interactive and fun and those are the best combinations for the learning to stick and you do apply it to your daily lives they just recently created a new course on logic and we could all probably use a little bit more logic in our lives but especially applying logic to the sciences the holiday season is also upon us so a brilliant subscription might be a great gift for a child a niece nephew 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Channel: Institute of Human Anatomy

Views: 2,820,520

Keywords: bones, human bones, human skeleton, skeleton, femur, humerus, bone tissue, what are bones made of, what are bones made out of, what makes bones, is calcium in bones, bone fracture, bone marrow, red bone marrow, yellow bone marrow, platelets, red blood cell, white blood cell, thrombocyte, leukocyte, erythrocyte, blood cells, blood cell formation, periosteum, medullary cavity, epiphysis, diaphysis, long bones, human anatomy, real anatomy, real human anatomy, anatomy, ioha, cadavers

Id: BsnKZDGSuw0

Length: 13min 34sec (814 seconds)

Published: Fri Dec 03 2021