Cadmore media player playing video Bone Metabolism For Postgraduate Orthopaedic Exams
Video Player
Accessibility
Using forms mode, you can utilize keyboard shortcuts to make usability more efficient.
Space bar will play and pause the video. Pressing escape will close all displays and pressing it again will jump to the end of the player.
You can press A to open the Keyboard Shortcut Dialog which also provides an audio description of the player and all of its features.
Language
1x
Play Speed
Adjust Volume
Transcript
Search
Result Count
of
Click to jump to result
Search
Re-center
Segments
Result Count
of
Click to jump to result
Search
Name:
Bone Metabolism For Postgraduate Orthopaedic Exams
Description:
Bone Metabolism For Postgraduate Orthopaedic Exams
Thumbnail URL:
https://cadmoremediastorage.blob.core.windows.net/41de7307-5ed0-44ab-b14d-e2e5eafc5dc7/videoscrubberimages/Scrubber_1.jpg
Duration:
T00H36M06S
Embed URL:
https://stream.cadmore.media/player/41de7307-5ed0-44ab-b14d-e2e5eafc5dc7
Content URL:
https://cadmoreoriginalmedia.blob.core.windows.net/41de7307-5ed0-44ab-b14d-e2e5eafc5dc7/Bone Metabolism For Postgraduate Orthopaedic Exams.mp4?sv=2019-02-02&sr=c&sig=5i5ntPfimNO4RbDIXOiNpZ%2FMpppa%2BgmyIImoMJKNlxU%3D&st=2024-11-23T12%3A02%3A32Z&se=2024-11-23T14%3A07%3A32Z&sp=r
Upload Date:
2024-05-31T00:00:00.0000000
Transcript:
Language: EN.
Segment:0 .
OK, guys. Good evening. Welcome to this teaching webinar.
This is organized by orthopedic Academy and also TV. My name is Firas arnaut, I'll be the host this evening. The presenter is set to come out. He is an orthopedic surgeon. He works in the UK in Rotterdam hospital and since passing his forces exam, he's been very active in teaching with orthopedic Academy.
He's presented multiple times and he is one of the faculty who you us. The courses and his presentations are always very well received. So we are very happy and pleased that he accepted the invitation to present tonight. Thank you. So we will just the session today is going to explain how it will run.
There will be a short lecture. Uh, it's very concise lecture and focused on what candidates need to know for the fastest exam. Following that, there will be a question and answer session when we listen to your questions. If you have any questions, please write them on the chat box or you can talk to the end of the session and directly ask your questions.
After that, we will have a short execu session when you be tested. You'll have three questions asked and we'll ask you all to answer these questions following them cq. We will be the final session, which will not be recorded, and it is a five hour session. So we will. You have a hot seat with a question when you'll be asked by members of the faculty if I've got a scenario for the exam.
So if you are interested to take part in the Viva, we please ask you to express your interest by either sending me a message or raise the hand symbol next to your name. So we know you are interested in taking part of the Viva session. This is very highly recommended. We understand what you need and we understand the stress you're under, so we will look after you, but it's very highly recommended that you take part in the Viva session.
But if you miss this, any part of this presentation or anything goes a little bit too quickly for you, don't worry, it's recorded and it will be posted. On the orthopedic Academy YouTube channel and also TV as well. So, yeah, just wanted to remind you guys of our courses, so we do orthopedic Academy three courses. One is the case based discussion course, which we only have six participants per course, and we spend all day with the participants going through 35 high yield exam specific questions.
We test you and then we give you the right answer at the end of how this each question should be answered and it's very, very focused day all day. So if you are interested in taking part of this course, we have one bas status of October and we have only one place left on it and then we have another course on the 11th of December. We also have our basic sciences course. And next course is on the 20th of November.
And all our courses are on Saturdays because we know you guys are very busy during the weeks, do you work? And also we have our emphasis mock exam course, very popular course, we have. It's basically just simulating the exam, how it goes. So we have a one on 23rd of October 4th of December and 22nd of January. So we would encourage each one of you, please to visit our website or through the Academy go UK.
Join arteriogram group or follow us on Twitter and YouTube. And if you have any questions, please send us a message. So without further ado, I leave you with Siddharth. Hello, sir. Today's topic of discussion is about bone and its metabolism. So let me share my screen. So bone metabolism is a topic for today, the emblem of orthopedics, I come from egawa, so I put the coconut tree there in the sea.
So bone is a composite connective tissue having a rigid structure, having cells embedded in calcified metrics coming to back. We've got cells there and we got metrics, which is further divided into two organic and inorganic. What are the functions of the bone? Why the bone is there? There have been times when the animal kingdom lived without the skeleton, but bone comes with functions of posture that is, the maintenance of erect posture and posture of limbs.
Protection of internal organs, for example. Visceral organs. The neutral organs. Proportion by legs and propulsion by hands. Hands to use and do the things. And legs to walk or run. Proprioception and production production of red blood cells. White cells, cells done by the bone marrow. So, Bowen, biomechanically is a very, very good structure and tailored to meet the demands.
Most of the most important function of Vaughan is to really maintain posture, and that is the stiffness. So one is. Biomechanically strong in compression is a bit weaker in tension, that is, if you pull out, it will just it's less stronger than compression weakest. When you twist the bone it it fractures easily rather than when you put tension or compression.
So you can see this. This is a long bone here femur of a child. You can see the fazil plates bone derives around 5% to 10% of cardiac output. So if you see the bone, we got the epiphytes this metaphysics and devices. So as you all know, this is epiphytes this. There which is separated from metathesis by the fazil paid the blood supply, which comes to the epiphytes, is in this context, it comes from the territory.
And there is a blood supply separately for dialysis, which has basically two person, while one comes through into the medical pod and it's called nutrient artery divides into two branches ascending and defending, and one is still the nutrient artery supplies most part of bone that is 2/3 of the diameter. It it is a lot of pressure and the flow is from inside out so that its barrier still is a low pressure system, in which the blood flows from outside in.
So this is the schematic diagram. You know that at some point in some bones and some joints, the epimysium blood vessel can cross the fight plate, and it has got implications in the clinical practice. I'll come to that later. So what are the types of wounds can be divided as far as the shape size, like a long bones, long shot, short bones, flat bones, irregular bones.
But if you see histologically, there can be histopathological. It can be divided into basically three types. One is immature type, which you can see in fractured colors or some very strong reactions. The mask is a mature, mature bone is divided again into two types. So this is a piece of mature bone. And you can see some areas there, which is middle east, some areas which are cortical.
So usually the cortical bone is a lamellar bone, which is a definite laminar and left structure where it's the cancellous bone in the macula is trabecular bone. That means it has trabecular running across in various directions. So to show you more that you can see this group of bones schematic, you go to the trabecular bone up and the lamellar bone down to the bone has got rid of bone running in various directions, whereas in the bone you got your own organized in a organized structure or Austrian.
I don't have a histology of the immature bone, but I can show you an X-ray of a fracture, which shows immature bone, which is poorly organized and has got a not so much biomechanical and biomechanical strength as as, like the mature bone. So how does the bone develop? The bone development is a systematic process regulated by various genes. So they say that around six to eight weeks for 4 to eight weeks basically the limb, but appears so the embryo throws off the slim bed, which got various zones.
One the. Brown area, which you can see yellowish Brown area is then it's the mid-autumn which is going and it just got topping off at bikel, which. And it has got a polarizing zone. So what does this basically do is these are regulated by genes, for example, proximal distal growth is modulated by oxygen and proposed by a suggestion and dorsal ventral by W a gene.
So total number of bones, which we have is 200 and six, and this is the way the limb bones are formed. So you got a limb bordewich elongates and it takes ectoderm and mesoderm with it, which further differentiates into types of bones and the shapes of bones. The limb, but for lower limb, actually develops a week or two after the upper limb Bud develops. So if you have looked at this diagram, you can see the primitive Mizoram having a primitive mesodermal cells.
And during the development of porn, we get some of them get transformed into pre osteoblasts. Which again, organized themselves and get converted into a strobe light, which throw off bone. And we have the intramembranous bone formation. One can also form another way in this way, the Metrodome forms a cottage and the look with a small primary center of ossification.
Which later on gets vascularized. Still, later on, we get a secondary center of fiction this and it gets vascularized. This goes into very many, many stages, but I just grossly mentioned the three stages. So you've got a cartilage analog which gets converted into bone. The primary center of ossification, the ossification, which starts before birth, with the exception of distal female, where a secondary centers of ossification comes after blood.
So when you say when we know that and the endochondral ossification and we got primary and secondary centers of ossification, how this boon further grew from the bottle for further. So for that, we have the fazil plate or growth plate, which has got various zones, like if you see growth plate, this is to wipe the AP physiol side. Whereas this is difficult side.
So if you see. On that Brazil side, you've got an artery, which supplies some resting cells, which are. Lined that the resting site soon proliferate and because they proliferate so quickly that they sometimes do not completely separate and they have a way appearance of getting stacked.
As they further grow, they go into third zone, which is a zone of hypertrophy in which there is a growth and the conversate become bigger and bigger. And finally, it ruptures and dies itself and release all its minerals and metrics into the system. Which for the becomes born? And we on the metaphysical side, you can see the already formed bond and arteries, which form a hair loop, which actually increases the circulation there and a tooth mineralization or ossification of Manila's most metrics.
So you'll ask me how much percentage of growth occurs at each point. So if you see a piddling 40% of growth across the shoulder with the elbow, it is 20% again, 40% hip proximal femur, just 12% knee is 70% Ankle is 18% So if you consider the lower limbs, nearly 1.5 centimeter of growth occurs per year at the knee, from the bird to skeletal maturity.
Which is around 12 to 14 years in girls and 14 to 16 year in boys. So coming back to the structure of a lamellar bone, we have never seen system. The basic model or basic unit is called Austrian. So if you see this diagram, you can see a cross section. You have some various GM gear having two layers.
One is fibrous and another is. Cellular, their cellular data is very important because it is important to have the breadth of the bone along with the land. So it's important it does give some positional growth. If you see the inside, you got a Harrisons canal, which which is a central canal through which artery and vein and now flows.
It is surrounded by. A La malevich, which are held by hostile sites and verite Nevada's they are there, the cementing occurs to this face the basic unit of the basic unit of a lamellar bone. We got two layers arranged in circles, which causes mineralization of metrics.
But what are the cells I told you about the cells insert some tiny dogs there, some cells, which are important. So if you see at the wound, this is a bone where you can have a cortex and medulla. The important cell, you know, is osteoclast because a lot depends on this. This is basically derived from radical engineered cells. It's a multinucleated cells which lies in the devices in the bone, and it has got a ruffled border through which the bone absorbs and AUKUS.
So whenever this cell is activated. It does two things. It releases enzymes, which dissolves the matrix. I told you sometime back that matrix is having two components. One is organic and one is inorganic. So organic component is basically college in college and one.
And some of the proteins. This is degraded by an enzyme called cathepsin, which is a proteolytic enzyme. The second part is minerals. Minerals are. In two forms, one is hydroxyapatite and second one is Brookside. So the second enzyme released by osteoclast called carbonic anhydrase dissolves this minerals and then blood vessels flush them away.
Well, this is a very important sell in bone turnover. The second cell, which is it's called osteoblasts, osteoblasts is derived from the Mason is derived from Minnesota. It goes to the progenitors and osteoblasts blast. Two birds are active cells. Why are they active? Is because they are separately.
And what do postulate separate or to blast secrete proteins? And the metrics and the protein, the main framework which forms the bone is something secreted by osteoblasts, and so phosphorylation becomes very important a cell. It undergoes three phases and either undergoes apoptosis and dies, or it can be converted into a lining cell or it gets converted into the next cell, which is astrocytes.
This is a fairly inactive cell. However, it has got a very important role in maintaining calcium, phosphorus, phosphorus and dishes. So this is the cell, which actually mineralization the inorganic matrix. So it basically in minerals is the matrix, the collagen matrix, which is created by osteoblasts.
So as I said earlier, mattress sutures is 70% of minerals, which gives construct to 30, which gives a compression to more than 30% organic, which gives the tensile strength or which awards or gives the strength against the bull on the bone. So when we see the Met or the organic component, we got collagen, which is a triple helical structure.
Made up of alpha genes and. The crystalline structure made up of hydroxyapatite. So these two combine so collagen molecules interact with each other and create small, small bits in which this. Uh, I don't see that, crystal. And that's what we call the bone matrix. So there are other proteins secreted by osteoblasts, which helps it's got some regulatory to point in periostin acting to calcium and elastin.
So suborning the constant turnover it it is, it gets reabsorbed and deposited. This is a very important cycle. So consider this a bit of bone, which is having the lines that are inactive was to blast. After some time, the rental stimulates osteoclasts and it eats some part of bone, and it creates a crater which is filled by the steel blast, which forms bone and cylinder fill the crater, which in turn will get replaced by the calcified matrix or systematics.
The help of astrocytes, which will deposit calcium and phosphate. So what are the mechanics in the bone? I told you. Bone growth occurs, but how does it affect what helps the bone growth? We got certain laws which help so. One is wolf's law, which said that the bone alliance, depending on how it is loaded.
So this can be best in the femoral head and neck, you can see this bone has a tensile load on the. The electron is stuck in a compressive load on the. Um, medial aspect. So Wolfthal said that it will reorganize itself as to the load and how much it meant for the site that if you use a tensile load can get elongated. If you compress, you load. There'll be no, it will not be so much elongated.
But because of compression, there's something else happens. Bone grows up rapidly, which had taken thickened rods, which basically are condensation of process material, giving extra strength to withstand the compression. There's another effect, which is also not knowing. So whenever there's a structure bent into a C shaped curve, there are changes in the electrical charges across.
So on the convex side, this will be forced to charge and on your site. There'll be a negative charge. So this was supposed to charge, it will bring the osteoclast and many the negative charge will get us to blast. So that's why the medial side is more dense than the lateral side. There are some. Um, chemicals which work on the bone important of which is vitamin d, is a fat soluble steroid from which comes from diet or sunlight.
So how does it come from diet that we eat? Diet, which already has got active or inactive vitamin d, which gets activated in body? But what I'm going to show you is how does the body make vitamin d? So we have a D high cholesterol in the skin, which gets converted into colic, also for the vitamin d, which gets a hydroxylase in the liver and then kidney to fill to form the.
Active vitamin d, which is also called Trillion. So 25 dihydroxyvitamin D is called City or so and active form is called calcium trio. And this is the one which is really important. The last step is regulated by Bharat hormone, which helps and facilitate conversion of vitamin D. 2.5 drops vitamin B2 eye 1,25 dihydroxyvitamin D.
So if you see the vitamin d, it's basically steroid so more easily stored several receptors which are inside the nucleus. So this is the vitamin D receptor in the nucleic acid and we have vitamin D here. It goes all across there and activates the certain genes which cause synthesis of proteins like collagen and.
It also synthesizes the enzymes like alkaline phosphatase, which helps the mineralization for the water, does it also for this proliferation of cells, which which causes the meiosis to occur more often? And we got a lot, many osteoblasts osteoclasts, which help in mineralization? So what are the actions of vitamin d.? Vitamin D is basically stabilizer of calcium and phosphate, so it does cause bone mineralization, but also cause proliferation of osteoclast and helps in the resorption if required it.
It absorbs calcium and phosphate from intestine and kidney. It inhibits the secretion of. Barbara tyerman, it promotes community and purposes and has got some antineoplastic action. It's also called a smooth muscle proliferation, so it's all healthy and type of vitamin D coming to next slide.
The other hormone, which is like calcium bit less, is called calcitonin, the 32 amino acid polypeptide secreted by peripheral blood cells and parathyroid. Basically, it works. It is a better osteoclast. It's got a receptor for questioning, which makes it inactive when it blocks the absorption of bone than by osteoblasts. So it's just to plastic.
And then third, chemical is better hormone secreted by the traject, by chip cells having a different amino acids. And basically, it comes as a precursor and then it is broken down to active form. Basically, parathyroid causes absorption of calcium from bone biology to place, but it also helps absorption of calcium from the intestine and kidneys. However, it causes inhibition of phosphate in absorption from the proximal tubule, so it's got a phosphorus loading effect.
It is stimulated by reduced calcium, magnesium and inhibited by vitamin D and. Increased calcium, so vitamin d, calcium, calcium in the three main factors which cause. And which which which maintains the bone homeostasis. So if you see the osteoblasts and osteoblasts sitting with the liner cells and an option, the astrocytes that. So when the parietal moon is there, actually osteoblasts is the one which is called a receptor for that.
So and wasn't just the receptor also lost or osteoblasts secretes rankle. Which goes and sits on the receptor in the osteoclast. So when this receptor is activated was to become activated, its full back to get it to, and there's the bone resorption ultimately when there's plenty of calcitonin. What is the creation of osteoporotic during which catches the wrinkle and does not allow it to sit and activate those two, plus the wrinkle has got a full name complicated 1 receptor activator of nuclear copper ligand.
So even if, say, rankle, it's enough. This is how it happens to the bone. In short, it's a very dynamic structure rich in blood supply, has got important function, has got a variation in structure and has got a living lifestyle. Thank you. Yes, I'd like to thank you very much for this very concise presentation. Specific and exactly at the level of their force, yes, exam, and I thank you for preparing all these media slides.
I'm sure it's not easy. A lot of work behind all of this. So thank you very much. I think we've covered a lot and I think most people would want to probably watch this. A few times, because, you know, basic science topics can be hard sometimes, but I think you've covered really a lot about bone metabolism there. Thank you very much, Siddharth.
Appreciate that. I think. And we will move on now to the second part, setting it and 3% have participated. Right so I think it's coming. There So I would ask you all guys to answer the questions. I hope you all can see them.
You know, it's anonymized, so no one can identify you. You just have a go. It's very good practice. And there are specific for the exam excuse once you will give you one minute better question. And then we will go through the answers that will go through the answers with you after that. So we remind you guys, while you're doing that, just after this part, we will go through, we'll have a Viva session.
So Siddharth has prepared some of the questions and we currently have one candidate only who is Mohammad javad, if anyone else interested. Please let me know if no one else express interest, then we will just have the one candidate. But if anyone else is interested, we have a maximum of three questions for the session. It's highly recommended to take part. It's good practice.
I would give you feedback, and we'll let you know. And it's a good, good learning for everyone. And all 18 have answered, so the question was primary pathology of osteoporosis lies in. So the answers were osteoblasts one or two class Ii mesenchymal cells III collagen four. So primary.
Pathology in osteoporosis is deficient osteoblasts, which 63% have answered, so this question is correctly answered by 63% OK not bad. Yeah, that's good. Around what you expect and exam, isn't it? Yeah, Yeah. Oh, another candidate has just joined. I think you just answered no. So second question is why this is intra articular in all, except one.
And the choices were wrist, elbow, ankle and hip. So 50 percent, which is 11 out of 20, I think one more candidate is on Search just now said it's wrist, which is a correct answer. There is a. Ankle, they said. The 30% case is not really correct, and question was bone mineral absorption. At truffled border of due to cathepsin alkaline phosphatase, osteoporotic urine or carbonic anhydrase.
So 45 percent, which is 9 out of 20, has answered it correctly. That is carbonic anhydrase. So I'll end the poll and I'll see if I can share the results. Much for explaining them. Siddharth, yeah, that's brilliant. Thank you very much. That's great, wonderful. Yeah, lovely. OK, guys, now if we're going to stop the recording and we will move on to the next part of this teaching session.
Uh, which is the survivor component exam, so that if you don't mind, please, can you get your first viva question ready? Yeah
Segment:0 .
OK, guys. Good evening. Welcome to this teaching webinar.
This is organized by orthopedic Academy and also TV. My name is Firas arnaut, I'll be the host this evening. The presenter is set to come out. He is an orthopedic surgeon. He works in the UK in Rotterdam hospital and since passing his forces exam, he's been very active in teaching with orthopedic Academy.
He's presented multiple times and he is one of the faculty who you us. The courses and his presentations are always very well received. So we are very happy and pleased that he accepted the invitation to present tonight. Thank you. So we will just the session today is going to explain how it will run.
There will be a short lecture. Uh, it's very concise lecture and focused on what candidates need to know for the fastest exam. Following that, there will be a question and answer session when we listen to your questions. If you have any questions, please write them on the chat box or you can talk to the end of the session and directly ask your questions.
After that, we will have a short execu session when you be tested. You'll have three questions asked and we'll ask you all to answer these questions following them cq. We will be the final session, which will not be recorded, and it is a five hour session. So we will. You have a hot seat with a question when you'll be asked by members of the faculty if I've got a scenario for the exam.
So if you are interested to take part in the Viva, we please ask you to express your interest by either sending me a message or raise the hand symbol next to your name. So we know you are interested in taking part of the Viva session. This is very highly recommended. We understand what you need and we understand the stress you're under, so we will look after you, but it's very highly recommended that you take part in the Viva session.
But if you miss this, any part of this presentation or anything goes a little bit too quickly for you, don't worry, it's recorded and it will be posted. On the orthopedic Academy YouTube channel and also TV as well. So, yeah, just wanted to remind you guys of our courses, so we do orthopedic Academy three courses. One is the case based discussion course, which we only have six participants per course, and we spend all day with the participants going through 35 high yield exam specific questions.
We test you and then we give you the right answer at the end of how this each question should be answered and it's very, very focused day all day. So if you are interested in taking part of this course, we have one bas status of October and we have only one place left on it and then we have another course on the 11th of December. We also have our basic sciences course. And next course is on the 20th of November.
And all our courses are on Saturdays because we know you guys are very busy during the weeks, do you work? And also we have our emphasis mock exam course, very popular course, we have. It's basically just simulating the exam, how it goes. So we have a one on 23rd of October 4th of December and 22nd of January. So we would encourage each one of you, please to visit our website or through the Academy go UK.
Join arteriogram group or follow us on Twitter and YouTube. And if you have any questions, please send us a message. So without further ado, I leave you with Siddharth. Hello, sir. Today's topic of discussion is about bone and its metabolism. So let me share my screen. So bone metabolism is a topic for today, the emblem of orthopedics, I come from egawa, so I put the coconut tree there in the sea.
So bone is a composite connective tissue having a rigid structure, having cells embedded in calcified metrics coming to back. We've got cells there and we got metrics, which is further divided into two organic and inorganic. What are the functions of the bone? Why the bone is there? There have been times when the animal kingdom lived without the skeleton, but bone comes with functions of posture that is, the maintenance of erect posture and posture of limbs.
Protection of internal organs, for example. Visceral organs. The neutral organs. Proportion by legs and propulsion by hands. Hands to use and do the things. And legs to walk or run. Proprioception and production production of red blood cells. White cells, cells done by the bone marrow. So, Bowen, biomechanically is a very, very good structure and tailored to meet the demands.
Most of the most important function of Vaughan is to really maintain posture, and that is the stiffness. So one is. Biomechanically strong in compression is a bit weaker in tension, that is, if you pull out, it will just it's less stronger than compression weakest. When you twist the bone it it fractures easily rather than when you put tension or compression.
So you can see this. This is a long bone here femur of a child. You can see the fazil plates bone derives around 5% to 10% of cardiac output. So if you see the bone, we got the epiphytes this metaphysics and devices. So as you all know, this is epiphytes this. There which is separated from metathesis by the fazil paid the blood supply, which comes to the epiphytes, is in this context, it comes from the territory.
And there is a blood supply separately for dialysis, which has basically two person, while one comes through into the medical pod and it's called nutrient artery divides into two branches ascending and defending, and one is still the nutrient artery supplies most part of bone that is 2/3 of the diameter. It it is a lot of pressure and the flow is from inside out so that its barrier still is a low pressure system, in which the blood flows from outside in.
So this is the schematic diagram. You know that at some point in some bones and some joints, the epimysium blood vessel can cross the fight plate, and it has got implications in the clinical practice. I'll come to that later. So what are the types of wounds can be divided as far as the shape size, like a long bones, long shot, short bones, flat bones, irregular bones.
But if you see histologically, there can be histopathological. It can be divided into basically three types. One is immature type, which you can see in fractured colors or some very strong reactions. The mask is a mature, mature bone is divided again into two types. So this is a piece of mature bone. And you can see some areas there, which is middle east, some areas which are cortical.
So usually the cortical bone is a lamellar bone, which is a definite laminar and left structure where it's the cancellous bone in the macula is trabecular bone. That means it has trabecular running across in various directions. So to show you more that you can see this group of bones schematic, you go to the trabecular bone up and the lamellar bone down to the bone has got rid of bone running in various directions, whereas in the bone you got your own organized in a organized structure or Austrian.
I don't have a histology of the immature bone, but I can show you an X-ray of a fracture, which shows immature bone, which is poorly organized and has got a not so much biomechanical and biomechanical strength as as, like the mature bone. So how does the bone develop? The bone development is a systematic process regulated by various genes. So they say that around six to eight weeks for 4 to eight weeks basically the limb, but appears so the embryo throws off the slim bed, which got various zones.
One the. Brown area, which you can see yellowish Brown area is then it's the mid-autumn which is going and it just got topping off at bikel, which. And it has got a polarizing zone. So what does this basically do is these are regulated by genes, for example, proximal distal growth is modulated by oxygen and proposed by a suggestion and dorsal ventral by W a gene.
So total number of bones, which we have is 200 and six, and this is the way the limb bones are formed. So you got a limb bordewich elongates and it takes ectoderm and mesoderm with it, which further differentiates into types of bones and the shapes of bones. The limb, but for lower limb, actually develops a week or two after the upper limb Bud develops. So if you have looked at this diagram, you can see the primitive Mizoram having a primitive mesodermal cells.
And during the development of porn, we get some of them get transformed into pre osteoblasts. Which again, organized themselves and get converted into a strobe light, which throw off bone. And we have the intramembranous bone formation. One can also form another way in this way, the Metrodome forms a cottage and the look with a small primary center of ossification.
Which later on gets vascularized. Still, later on, we get a secondary center of fiction this and it gets vascularized. This goes into very many, many stages, but I just grossly mentioned the three stages. So you've got a cartilage analog which gets converted into bone. The primary center of ossification, the ossification, which starts before birth, with the exception of distal female, where a secondary centers of ossification comes after blood.
So when you say when we know that and the endochondral ossification and we got primary and secondary centers of ossification, how this boon further grew from the bottle for further. So for that, we have the fazil plate or growth plate, which has got various zones, like if you see growth plate, this is to wipe the AP physiol side. Whereas this is difficult side.
So if you see. On that Brazil side, you've got an artery, which supplies some resting cells, which are. Lined that the resting site soon proliferate and because they proliferate so quickly that they sometimes do not completely separate and they have a way appearance of getting stacked.
As they further grow, they go into third zone, which is a zone of hypertrophy in which there is a growth and the conversate become bigger and bigger. And finally, it ruptures and dies itself and release all its minerals and metrics into the system. Which for the becomes born? And we on the metaphysical side, you can see the already formed bond and arteries, which form a hair loop, which actually increases the circulation there and a tooth mineralization or ossification of Manila's most metrics.
So you'll ask me how much percentage of growth occurs at each point. So if you see a piddling 40% of growth across the shoulder with the elbow, it is 20% again, 40% hip proximal femur, just 12% knee is 70% Ankle is 18% So if you consider the lower limbs, nearly 1.5 centimeter of growth occurs per year at the knee, from the bird to skeletal maturity.
Which is around 12 to 14 years in girls and 14 to 16 year in boys. So coming back to the structure of a lamellar bone, we have never seen system. The basic model or basic unit is called Austrian. So if you see this diagram, you can see a cross section. You have some various GM gear having two layers.
One is fibrous and another is. Cellular, their cellular data is very important because it is important to have the breadth of the bone along with the land. So it's important it does give some positional growth. If you see the inside, you got a Harrisons canal, which which is a central canal through which artery and vein and now flows.
It is surrounded by. A La malevich, which are held by hostile sites and verite Nevada's they are there, the cementing occurs to this face the basic unit of the basic unit of a lamellar bone. We got two layers arranged in circles, which causes mineralization of metrics.
But what are the cells I told you about the cells insert some tiny dogs there, some cells, which are important. So if you see at the wound, this is a bone where you can have a cortex and medulla. The important cell, you know, is osteoclast because a lot depends on this. This is basically derived from radical engineered cells. It's a multinucleated cells which lies in the devices in the bone, and it has got a ruffled border through which the bone absorbs and AUKUS.
So whenever this cell is activated. It does two things. It releases enzymes, which dissolves the matrix. I told you sometime back that matrix is having two components. One is organic and one is inorganic. So organic component is basically college in college and one.
And some of the proteins. This is degraded by an enzyme called cathepsin, which is a proteolytic enzyme. The second part is minerals. Minerals are. In two forms, one is hydroxyapatite and second one is Brookside. So the second enzyme released by osteoclast called carbonic anhydrase dissolves this minerals and then blood vessels flush them away.
Well, this is a very important sell in bone turnover. The second cell, which is it's called osteoblasts, osteoblasts is derived from the Mason is derived from Minnesota. It goes to the progenitors and osteoblasts blast. Two birds are active cells. Why are they active? Is because they are separately.
And what do postulate separate or to blast secrete proteins? And the metrics and the protein, the main framework which forms the bone is something secreted by osteoblasts, and so phosphorylation becomes very important a cell. It undergoes three phases and either undergoes apoptosis and dies, or it can be converted into a lining cell or it gets converted into the next cell, which is astrocytes.
This is a fairly inactive cell. However, it has got a very important role in maintaining calcium, phosphorus, phosphorus and dishes. So this is the cell, which actually mineralization the inorganic matrix. So it basically in minerals is the matrix, the collagen matrix, which is created by osteoblasts.
So as I said earlier, mattress sutures is 70% of minerals, which gives construct to 30, which gives a compression to more than 30% organic, which gives the tensile strength or which awards or gives the strength against the bull on the bone. So when we see the Met or the organic component, we got collagen, which is a triple helical structure.
Made up of alpha genes and. The crystalline structure made up of hydroxyapatite. So these two combine so collagen molecules interact with each other and create small, small bits in which this. Uh, I don't see that, crystal. And that's what we call the bone matrix. So there are other proteins secreted by osteoblasts, which helps it's got some regulatory to point in periostin acting to calcium and elastin.
So suborning the constant turnover it it is, it gets reabsorbed and deposited. This is a very important cycle. So consider this a bit of bone, which is having the lines that are inactive was to blast. After some time, the rental stimulates osteoclasts and it eats some part of bone, and it creates a crater which is filled by the steel blast, which forms bone and cylinder fill the crater, which in turn will get replaced by the calcified matrix or systematics.
The help of astrocytes, which will deposit calcium and phosphate. So what are the mechanics in the bone? I told you. Bone growth occurs, but how does it affect what helps the bone growth? We got certain laws which help so. One is wolf's law, which said that the bone alliance, depending on how it is loaded.
So this can be best in the femoral head and neck, you can see this bone has a tensile load on the. The electron is stuck in a compressive load on the. Um, medial aspect. So Wolfthal said that it will reorganize itself as to the load and how much it meant for the site that if you use a tensile load can get elongated. If you compress, you load. There'll be no, it will not be so much elongated.
But because of compression, there's something else happens. Bone grows up rapidly, which had taken thickened rods, which basically are condensation of process material, giving extra strength to withstand the compression. There's another effect, which is also not knowing. So whenever there's a structure bent into a C shaped curve, there are changes in the electrical charges across.
So on the convex side, this will be forced to charge and on your site. There'll be a negative charge. So this was supposed to charge, it will bring the osteoclast and many the negative charge will get us to blast. So that's why the medial side is more dense than the lateral side. There are some. Um, chemicals which work on the bone important of which is vitamin d, is a fat soluble steroid from which comes from diet or sunlight.
So how does it come from diet that we eat? Diet, which already has got active or inactive vitamin d, which gets activated in body? But what I'm going to show you is how does the body make vitamin d? So we have a D high cholesterol in the skin, which gets converted into colic, also for the vitamin d, which gets a hydroxylase in the liver and then kidney to fill to form the.
Active vitamin d, which is also called Trillion. So 25 dihydroxyvitamin D is called City or so and active form is called calcium trio. And this is the one which is really important. The last step is regulated by Bharat hormone, which helps and facilitate conversion of vitamin D. 2.5 drops vitamin B2 eye 1,25 dihydroxyvitamin D.
So if you see the vitamin d, it's basically steroid so more easily stored several receptors which are inside the nucleus. So this is the vitamin D receptor in the nucleic acid and we have vitamin D here. It goes all across there and activates the certain genes which cause synthesis of proteins like collagen and.
It also synthesizes the enzymes like alkaline phosphatase, which helps the mineralization for the water, does it also for this proliferation of cells, which which causes the meiosis to occur more often? And we got a lot, many osteoblasts osteoclasts, which help in mineralization? So what are the actions of vitamin d.? Vitamin D is basically stabilizer of calcium and phosphate, so it does cause bone mineralization, but also cause proliferation of osteoclast and helps in the resorption if required it.
It absorbs calcium and phosphate from intestine and kidney. It inhibits the secretion of. Barbara tyerman, it promotes community and purposes and has got some antineoplastic action. It's also called a smooth muscle proliferation, so it's all healthy and type of vitamin D coming to next slide.
The other hormone, which is like calcium bit less, is called calcitonin, the 32 amino acid polypeptide secreted by peripheral blood cells and parathyroid. Basically, it works. It is a better osteoclast. It's got a receptor for questioning, which makes it inactive when it blocks the absorption of bone than by osteoblasts. So it's just to plastic.
And then third, chemical is better hormone secreted by the traject, by chip cells having a different amino acids. And basically, it comes as a precursor and then it is broken down to active form. Basically, parathyroid causes absorption of calcium from bone biology to place, but it also helps absorption of calcium from the intestine and kidneys. However, it causes inhibition of phosphate in absorption from the proximal tubule, so it's got a phosphorus loading effect.
It is stimulated by reduced calcium, magnesium and inhibited by vitamin D and. Increased calcium, so vitamin d, calcium, calcium in the three main factors which cause. And which which which maintains the bone homeostasis. So if you see the osteoblasts and osteoblasts sitting with the liner cells and an option, the astrocytes that. So when the parietal moon is there, actually osteoblasts is the one which is called a receptor for that.
So and wasn't just the receptor also lost or osteoblasts secretes rankle. Which goes and sits on the receptor in the osteoclast. So when this receptor is activated was to become activated, its full back to get it to, and there's the bone resorption ultimately when there's plenty of calcitonin. What is the creation of osteoporotic during which catches the wrinkle and does not allow it to sit and activate those two, plus the wrinkle has got a full name complicated 1 receptor activator of nuclear copper ligand.
So even if, say, rankle, it's enough. This is how it happens to the bone. In short, it's a very dynamic structure rich in blood supply, has got important function, has got a variation in structure and has got a living lifestyle. Thank you. Yes, I'd like to thank you very much for this very concise presentation. Specific and exactly at the level of their force, yes, exam, and I thank you for preparing all these media slides.
I'm sure it's not easy. A lot of work behind all of this. So thank you very much. I think we've covered a lot and I think most people would want to probably watch this. A few times, because, you know, basic science topics can be hard sometimes, but I think you've covered really a lot about bone metabolism there. Thank you very much, Siddharth.
Appreciate that. I think. And we will move on now to the second part, setting it and 3% have participated. Right so I think it's coming. There So I would ask you all guys to answer the questions. I hope you all can see them.
You know, it's anonymized, so no one can identify you. You just have a go. It's very good practice. And there are specific for the exam excuse once you will give you one minute better question. And then we will go through the answers that will go through the answers with you after that. So we remind you guys, while you're doing that, just after this part, we will go through, we'll have a Viva session.
So Siddharth has prepared some of the questions and we currently have one candidate only who is Mohammad javad, if anyone else interested. Please let me know if no one else express interest, then we will just have the one candidate. But if anyone else is interested, we have a maximum of three questions for the session. It's highly recommended to take part. It's good practice.
I would give you feedback, and we'll let you know. And it's a good, good learning for everyone. And all 18 have answered, so the question was primary pathology of osteoporosis lies in. So the answers were osteoblasts one or two class Ii mesenchymal cells III collagen four. So primary.
Pathology in osteoporosis is deficient osteoblasts, which 63% have answered, so this question is correctly answered by 63% OK not bad. Yeah, that's good. Around what you expect and exam, isn't it? Yeah, Yeah. Oh, another candidate has just joined. I think you just answered no. So second question is why this is intra articular in all, except one.
And the choices were wrist, elbow, ankle and hip. So 50 percent, which is 11 out of 20, I think one more candidate is on Search just now said it's wrist, which is a correct answer. There is a. Ankle, they said. The 30% case is not really correct, and question was bone mineral absorption. At truffled border of due to cathepsin alkaline phosphatase, osteoporotic urine or carbonic anhydrase.
So 45 percent, which is 9 out of 20, has answered it correctly. That is carbonic anhydrase. So I'll end the poll and I'll see if I can share the results. Much for explaining them. Siddharth, yeah, that's brilliant. Thank you very much. That's great, wonderful. Yeah, lovely. OK, guys, now if we're going to stop the recording and we will move on to the next part of this teaching session.
Uh, which is the survivor component exam, so that if you don't mind, please, can you get your first viva question ready? Yeah
Form Title Download
Transcript
Form Title Bookmark
Entire Media
Segment(s)
Custom Clip
Start At:
End At:
Form Title Share
Entire Media
Segment(s)
Custom Clip
Start At:
End At:
Form Title Accessibility and Keyboard Shortcuts
The cadmore media player is a professional video and audio player experience designed to deliver media as well as relevant transcript, segmentation, and metadata. On the screen is a traditional html video player with buttons such as play, pause, forward, captioning, language and play speed selection and more. Adjacent to the video player are generally tabs, one of which shows a scrolling transcript of the video and the other shows any segmentation of the media, sometimes referred to as chapters. At the top of the video is a menu bar containing an Explore button and Tools button. The Explore button allows you to dig deeper into the video by opening up an explore dialog which contains tabs for a visual navigation of the video using thumbnails, an about tab which contains rich metadata about the media, a segments tab which contains further information about the video, and a related tab which contains links to other media related to this media. The tools button opens a menu with options for sharing the media on social media, creating bookmarking links, creating embed codes for your website, generating citations, and more.
Keyboard Shortcuts
Keyboard shortcuts only work while you are in forms mode. By entering forms mode, you will be able to quickly access portions of the media player with single key commands.
Spacebar: Play/Pause Toggle
I: Info Menu,
O: Tools Menu
T: Transcript Tab,
S: Segments Tab
F: Forward 15,
R: Rewind 15
L: Languages,
P: Playspeed
M: Mute Toggle,
V: Volume Bar
N: Video Only Toggle,
B: Full Screen Toggle
C: Captions Toggle
Escape: Closes dialogs and menus / Exits Player
Z: Next Transcript Chapter
X: Previous Transcript Chapter
Q: Next Transcript Paragraph
W: Previous Transcript Paragraph
Entire Media
Segment(s)
Custom Clip
Start At:
End At:
Embed Size
-
You Size - Responsive
-
We Size - Responsive
-
Picture Overlay Popup
-
400 x 225
-
512 x 288
-
400 x 700
-
768 x 1024
-
1024 x 512
-
1280 x 608
Form Title Cite
No citation provided.
Info
Segments
Related
Thumbnails
Exit Clip Mode
You have requested to see a portion of the video outside of the clip.
Click OK to switch to the full video or click if you would like to stay inside the clip. You can always go back to the clip with Tools and Clip Mode