 Hey everybody Dr. O here. Welcome to the skeletal system. So what is the skeletal system? It is all the bones of the skeleton plus the connective tissues, the cartilage and ligaments and stabilizing tissues that hold it all together. So when you think of the skeletal system let's go ahead and talk about the primary functions. You probably think of support and structure and these kind of things and that's a big deal but there are some other ones as well. So support is the first function of the skeletal system. I like to think of if you didn't have the skeleton you'd basically be a puddle on the ground and that's because your skeleton is what gives you your frame. Number two you know sticking with support we have this idea of protection. You have your ribs protecting your lungs, your sternum protecting your heart, these types of things. So protection you have your skull protecting your brain. So support, protection and then leverage or movement. So we'll cover the muscular system next but your muscles couldn't do anything. Muscles just shorten how they the fact that they create force and generate movement is because of where they are attached on your bones. So support, protection and leverage are probably the three that people think of the most often with your skeletal system but we also have storage and then blood cell protection. So for storage we have storage of minerals. When you think of the minerals in your skeletal system you should think calcium first about 99% of your body's calcium is stored in your bones but there are lots of other minerals stored in your bones as well. Malibdanum boron a whole host of them. So mineral storage and we'll come back to that in just a moment but then also some lipid storage. So we don't we don't think about this but a lot of our bones once we've once we've reached adulthood are full of yellow marrow they're full of fat that's why dogs love bones so much they try to break them open to get into this kind of fatty treat. So there's a little bit of lipid storage I think that's pretty minor but mineral storage very big deal we'll come back to that in just a moment and then lastly we have blood cell production. So the one that people forget the most often is the fact that inside your bone we have red bone marrow which is where your blood cells are produced. So support protection leverage those are the physical traits of these tough bones that we have but then there's also storage especially mineral storage and then we have the blood cell production. Okay a couple more things here let's talk about the two types of marrow just one more time here you do red marrow is going to be where hematopoiesis or blood cell production takes place we'll cover that in amp2 yellow marrow is going is going to be fat so what once when when you're a kid all your bone marrow is going to be red and then slowly it transitions into yellow marrow except for the epiphasies or the ends of your long bones and then some of these flat bones like you see here the ilium the head of the femur which is an epiphasis and the scapula still have still have in your ribs these kind of places would still have red marrow in adulthood that's why if they're going to do a bone marrow biopsy or transplant they usually go right there into the ilium to get it so my father gave bone marrow to his brother and and they dipped into his ilium to get that bone marrow but the first thing I think of when we talk about this more nutrition but the first thing I think about with bones is the calcium right you see bones and you want big strong healthy bones your body sees a calcium storage depot so when when you think of the functions of calcium making strong healthy bones is actually the least of your body's worries and that's because your body is constantly trying to keep you alive right now I like to look at this way your body's trying to maintain home real stasis for the next five seconds then the next five seconds then the next five seconds so having you know I'm 41 now having long having strong bones into my 80s would be great but my body has to use calcium for so many other things now that it's that's more important every muscle contraction requires calcium neurotransmitter release so every time a nerve fires calcium is needed calcium is needed for balancing pH issues and all sorts of things so your body will make strong bones if there's more than enough calcium if there's not then your bones are going to have to be sacrificed your bones are going to get weaker a little bit every day as your body constantly has to dip into them and take the calcium out alright that's red and yellow marrow last just introductory thing that I think of when it comes to the skeleton is how all our bones are so different but it's because they all have a unique job to do right so every bone has a particular function and it's going to and its structure is going to be built for that like if you look at like a lumbar vertebra in your low back is going to be much bigger and denser and thicker than a cervical vertebra well a cervical vertebra is primary job is to allow for lots of movement it doesn't have to support a lot of weight even if you have a huge head like I do but a lumbar vertebra is not going to allow for near as much movement but it's going to be have to support all of my body weight that's at least above my waist or you think about like your femur your big big leg bones going to be much bigger and have larger attachment points for bigger muscles than the bones of your arm because our legs have to be stronger than their arms as we carry our body weight around so I think that that's that's plenty for now this is the skeletal system I hope I hope you learn a lot like we'll look at bone as a tissue first and then we're going to look we'll go through the the two parts of the skeleton our axial skeleton and our appendicular skeleton so let's dive in I hope this helps have a wonderful day be blessed