adequate vitamin intake and mineral intake as well as a healthy diet is necessary for you to maintain bone growth and bone maintenance so we're gonna talk a little bit about the different vitamins and hormones that will affect bone growth and maintenance first is vitamin C not only is it important in most of your body's metabolic processes but it is also necessary for collagen synthesis so when we produce collagen vitamin C is one of the main factors in producing functional collagen without vitamin C collagen is still produced but it's not made correctly so we lose its strength so any tissue with vitamin C in it I mean with collagen in it and you have a vitamin C deficiency will be weakened so bone has collagen in it and your bones can get really weak if your vitamin C your skin the dermis is primarily going to be made up of collagen and you get Bruce is really easily the ligaments that hold your bones and teeth in place will weaken and that's what we're seeing in this picture vitamin C deficiency is known as scurvy and scurvy was often known as a pirates disease because when they were out on the ships for a very long time they would finish off any type of citrus or leafy vegetable food first which are always high in vitamin C so without that they were going to a deficiency and develop bruising broken bones loss of teeth scurvy is reversible but once you lose your teeth that's not something that you can regain now vitamin b12 deficiency it's really important for osteoblast activity so when you have a deficiency osteoblasts do not function as efficiently so we need to have a lot of vitamin b12 to help us maintain your bone metabolism if you have low b12 over long periods of time it will eventually lead to osteoporosis because it is not encouraging the functioning of osteoblasts to build new bones matrix no vitamin D we've talked about vitamins and vitamin Z's active form is known as calcitriol and when we talk about vitamin Z you can get it in your diet but your body can also naturally make it now vitamin D was named a vitamin because when they first discovered it they did think it was a vitamin but then they realized that your body could also synthesize it so they also will act as a hormone so if you're not getting it in your diet you need to be exposed to around 10 minutes of sunlight a day UV light basically initiates vitamin D to be produced in your skin but it's not active vitamin D so that molecule will travel to your liver in your liver it will be modified and from the liver it will go into your kidney well it would be the final modifications are made when the final modifications are made basically it's an addition of two OHS two hydroxy groups we not call this calcitriol calcitriol main effect is going to be to increase calcium absorption from food in your intestines but calcitriol does also affect bone resorption so it also increases osteoclast activity the main function of active four vitamins e calcitriol will be increased calcium absorption from the diet in your intestines next is HGH human growth hormone um this is a anabolic hormone meaning that it just basically causes things to be built now it affects pretty much every cell of your body but this is a chapter on bone so HGH is going to be released from your pituitary gland when it's released from the pituitary gland growth hormone is going to travel to the liver in the liver it's going to target the release of insulin like growth factors IGFs now IGFs are going to be released from the liver in the presence of HGH and when they're released they're going to actually go target the epiphyseal plate and in the epiphyseal plate what you're going to have is chondrocytes that can divide so IGS will help increase chondrocytes of vision now think back to what zone has the conscious sights dividing if you said proliferating you're correct so IGFs of targeting conscious sights that are going to divide in the proliferating zone now IGS will also target osteoblasts to increase their function so when IG FS are telling chondrocytes to divide more rapidly they're also telling osteoblasts to lay down bone more rapidly so HGH and IGF is very important in bone growth in length the interstitial growth at the epiphyseal plate now if you continue to produce a lot of HGH after your epiphyseal plates have closed epiphyseal lines it leads to a disorder known as acromegaly and you're gonna end up having the growth plates aren't sorry the growth lines still continue to develop so excessive bone gets laid down in these areas and your hands feet the mandible they all start to take on a disfigurement because they keep getting larger if you don't produce enough HGH what will lead to is some types of dwarfism achondroplasia is not a door fizz and that's caused by an HGH issue it is improper functioning of the epiphyseal plate when you're born so due to genetic factors you epiphyseal plates do not grow as rapidly as they should so individuals with achondroplasia are considered little people they have normal-sized torsos but in heads but their arms and their legs are not going to be in proportion to the rest of their body now other hormones that are really important are going to be your sex hormones that are released in high amounts at puberty your sex hormones estrogen and androgens specifically testosterone are the ones that people are most familiar with estrogens are really important because they um promote osteoblast activity in inhibit osteoclast activity so basically going throughout life you're producing all this estrogen and for females around menopause they stop producing estrogen so osteoblast activity declines why osteo class activity increases and then testosterones are the normal hormone that you've hear a lot about with males their role isn't as studied when we talk about aging but a deficiency in testosterone can lead to low bone density or low bone mass and it has shown that it does play a role in bone formation females now when we talk about other bone disorders we have osteomalacia and rickets this is known as softening of the bones osteomalacia and rickets doesn't mean that bone wasn't formed it just never hardened so rickets is basically a childhood disease because it's only going to affect the epiphyseal plates and osteomalacia can be basically the childhood our adult version it's gonna affect the other parts of the bone so you can often see bow legs and bowed arms because the plates are gonna bulge at the areas that you're putting stress on them because it's not hardening fast enough and these bones are also easily broken osteomalacia and rickets again very similar disease but rickets is going to be in children and that plates where as ah stimulation is going to be the rest of the bone both these diseases can be caused by diet so if you're not getting enough calcium in your diet that means there's no calcium to deposit in the bones or you can have a vitamin D deficiency so the active form calcitriol is not present to help you absorb calcium or it could be a genetic factor oftentimes rickets osteomalacia are seen in child abuse cases when children are not allowed outside another interesting disorder is osteogenesis perfect so basically this is a disorder where your collagen fibers aren't being formed properly and collagen is really important because collagen is giving strength to your bones so without proper collagen the bones can break really easily so what happens with individuals is osteogenesis imperfecta is they can have numerous broken bones throughout their life are even before they're born depending on the severity of it and since I don't wanted to show you a broken bone picture what I'm showing you is the scleras of the eyes those are the whites of the eyes are gonna kind of take a bluish or grayish tint to them if you have this disorder because the whites of the eyes are made up of dense irregular connective tissue which is basically collagen fibers in all different directions and since the collagen fibers aren't forming properly it's thinner and when you're looking into the eyes you're actually seeing the coloration of the retina in the back of the eye which is a black color so we're seeing that bluish great chance now Accio Genesis imperfecto is also a disease that was part of a movie known as unbreakable we've already talked briefly about achondroplasia again it is an abnormal gene activity on chromosome 4 and basically it's affecting your fibroblast activity which affects collagen fibers and so the epiphyseal plate cartilage goes really slowly so it's again it affects the appendages but the torso is normal another odd one is Myositis ossificans basically it's when bone invades non bone tissue so your muscles can be invaded by mesenchymal cells and there's mesenchymal cells when they get into the muscle we'll say okay I'm gonna turn into bone cells and it's going to cause hardening of muscles it causes bones to fuse together it's a really really rare there's not many cases of it out there but it's just an interesting disorder to know about and then another one that is caused by calcium being deposited in high high amounts on the cranium and what happens is you have all these little holes in your cranium called for raymond's or slits and the more cowson that gets deposited it narrows those holes which pressors pressure on different nerves and blood vessels causing them not to function properly but there was a movie made about cranio diaphyseal dysplasia also known as lion itís called the mask it was about a kid named Roy Lee but they called him rocky and here's just a little clip about the disorder so these are just interesting clips so you realize that these types of disorders are prevalent in the population and this is a way for them to get the word out there about what's going on our next one is going to be osteoporosis so osteoporosis is going to be weakening of already formed bone and osteoporosis is extremely prevalent in populations especially female populations over 50 to 55 because of the implementations of estrogen not being produced so what happens in osteoporosis is the bone that was previously there starts to degrade so you're actually having a decrease in the amount of bone strength to the loss of bone mass um basically osteoclast are out working osteoblasts so bone resorption taking the calcium out of the bone into the blood is increasing while bone deposition osteoblasts laying down new bone is decreasing um bone health and osteoporosis is affected by a lot of things one thing that we're gonna see is that osteoporosis affects spongy bone first because it's easier to resorb calcium from areas with more surface area so different things that might affect osteoporosis is vitamin d if you don't have a lot of vitamin Z then you're not going to be able to absorb calcium without calcium your bones density is gonna be weakened okay weight-bearing exercises the more stress you put on your bones the thicker they become so bones are going to build around areas of stress and different athletes have are different types of athletes will have different types of bone formation so an athlete that is a runner they might have thicker Linea aspera on their femurs which is basically kind of a ridge on the back of your thief's femur due to the weight name medications can definitely affect your bones ability to lay down new bone or absorb calcium risk factors so hereditary factors history genetics alcohol alcohol is really important alcohol is actually toxic to osteoblasts so knowing that affects that alcohol can have will only help you stay healthier so if osteoblasts are being killed based on your drinking and your ability for bone to be built will be lessened and then smoking smoking decreases the amount of estrogen in individuals estrogen promotes osteoblast activity so osteoporosis is affected by many many things what you can control is diet and exercise those are things that you can actually control on how your bones are affected when osteoporosis it occurs it's going to affect your vertebrae hips and wrists the first because those particular bones have a lot of spongy bone in it and again remember it's easier to break down and remove calcium from high surface areas so we're gonna watch a quick videos on osteoporosis you