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And then we start. OK, we're gonna start now guys. So um yeah, so again, as everyone knows, so I'm poor year. So I'm a second year medical student. So we're gonna talk about um cardiovascular respiratory anatomy for today and this is just a disclaimer that this has been made by our committee and not verified by the university. So it's just take it as a tool for your learning, not uh something that you would say just um just go for a base on this for your exam. So the aims on objects of our session today are we are gonna essentially try to understand what is meant for media sinum, er the main divisions, we're also gonna talk about uh the main features of the heart and also pericardium er including er innervation as well. So, nerves er mainly and we're gonna talk about heart borders and surface as well, which uh can help you visualize how heart is essentially like positioned in your er thorax. We're gonna talk about uh the blood supply to your heart. So specifically the coronary arteries, we're also gonna talk about uh the atriums and the ventricles and the main structures you need to know about uh inside. We are also gonna talk about the surface anatomy of the heart and essentially how to listen to heart sounds. And um we are gonna talk about the assimilation. Uh So essentially electrical assimilation pathway of the heart as well. Uh That is a very common in the exams again. And we are gonna talk about uh like different structures of the thorax. So we're just gonna move on to uh respiratory as well a little bit and talk about innovations, blood supplies, then we will move on to some muscles of the thorax as well. And um there are innovations as well and we're gonna specifically look at neurovascular bundle and its importance and why do we need to know about it essentially. And we're gonna talk about other structures like pleura trachea and we're gonna discuss the mechanism for breathing and also er diaphragm as well. So uh we're also gonna discuss how to be able to essentially uh interpret basic structures and x rays. So this is a skill that will help you later on in your career as well. But also at this stage, they could essentially give you x rays and ask you to identify structures in a phase one exam as well. So don't feel like, oh, you're never gonna be asked this, you might um still be asked. So, yeah. Um So we are gonna start with Mediastinum. So firstly, if we look at the picture at the right, we can see, OK, there's a lot of different divisions, the main divisions for Mediastinum are superior and inferior. So uh I'll just give you guys a hint. So the top right one at the l right image is the superior Mediastinum. So if we now look at the left picture, we have three gaps. So there are uh the three different divisions of the inferior Mediastinum. So let's start with the top left gap. Can anyone tell me put in the chat on mute yourself? What division of the mediastinum is that? So if you're not looking at any specific structures, I don't want you to name this is structure. To me say this is called this. I want you to tell me what is that um a specific division called. So the green on the left image, any ideas? So good thinking on the right side, you're absolutely right, Annabelle. So on the right side, it is called the superior or it's just referring to a left image. So the left image is the green. Um Yeah, s say it. So you're right. So it is anterior division good. So there are the three divisions of the inferior mediastinum. So we talked about the first one being anterior. So what would uh the second arrow that's po pointing to the right to the yellow image? So the heart essentially, what is that one referring to is that which section is that? So which re section of um the media sta is the heart located in. Yeah, absolutely. So it's middle, inferior spot on good. What about the last one? So what is the little blue just postero to the heart? So what do we call that one? Any ideas? So realistically that one was anterior middle, so was gonna be the posterior one called Absolutely annabelle. So well done, be good. So it is called poster spot on. Um Yeah, so let's move on. So another very important concept that you're gonna under you need to understand essentially is the arch of the aorta. So essentially er the ascending aorta that comes out of your er heart is gonna arch and there's gonna be separate things coming out of it. So the right er branch, the er the right branch that you can see here is gonna be called the brachiocephalic artery, which essential it like consists of two arteries, the right common carotid and the right subclavian artery. So the way that you can remember which one is uh essentially like media, which one is lateral is. I imagine the fact that um the common carotid is gonna supply your heart. So it doesn't want to go to your limbs. So it is logical for it to be medial. So it would supply your brain rather than going to your limbs. On the other hand, the subclavian artery has to supply your upper limb. So it would essentially branch out um and be lateral so you could go to your limbs quite easily. On the left side, you don't get the brachycephalic anymore. So you just have two separate divisions called left, common carotid and the left sub subclavian artery. Another key feature to identify here is where the coronary arteries come from. So the coronary arteries originate from the ascending aorta. So it specifically from the va like er so like er from the cusps of like the valve of the aorta, that's where they're gonna be coming from. Specifically that you will learn about its um implications later on when you do conditions of the heart. So if we move a bit more inside the heart, we'll actually encounter some different structures. So in a fetus, we have two structures called doctor's arteriosis and and ovale. So the entire point of it is to actually we're gonna get to this. So we are gonna talk about what the entire point is, but they're essentially shunting. So they are like making blood flow from one place to the other. So a doctor's arteriosis connects your artery of the aorta to the pulmonary artery and uh your foremen valid, it is gonna connect your right atrium to your left atrium. So, OK, do you guys know why do we need to have these structures in an unborn? So before I explain it is, do do you have any ideas? Why do we even need it? So why does the fetus need to have a shunting from their aorta. Er, sorry. So, from, yeah. So, er, from like, between their pulmonary artery and aorta or why would they potentially need it between the Atria? Any ideas? That's only shy? So he's absolutely fine if you have no ideas. Yeah. Annabelle. So, um, blood already oxygenated don't need to pump to lungs. Absolutely. 100%. So it is already oxygenated by the mother's lungs. So you don't need to actually send it to lungs and yeah. So spot on. So it happens at placenta. So you don't need to be able to uh essentially get anything. And also the pressure in your lungs is very high. So your lungs as a fetus is filled with fluid. So you can actually push, there's not much point in pushing so much uh like blood there anyways. So what you will do is you will shunt it from your pulmonary artery to your aorta. And that's gonna make sure your blood just directly goes to your organs. So, very well done guys. So let's talk about superior media stum as well. So it's a bit of um broader one. So it's not the most common in the exam question. So, but again, it's very important to know. So the main things you need to know about superior media stom is the ESSE essentially the veins. So we have the superior Vena Gava that comes down and we have the inferior Vena Gava that goes up and they're gonna meet together and they're just gonna go back to the heart. But you also need to understand, uh, where does the superior vena cava come from? Where does the inferior come from come from? So, superior vena cava comes from internal carotid artery that essentially drains your um, brain. And um, it's gonna join with your subclavian or uh subclavian vein that essentially drains blood back from your limbs and it's just gonna make the brachycephalic er, vein. So, we have the right brachycephalic and the left brachiocephalic and those brachiocephalic again combined together to make the superior vena cava as you can see. So now the inferior vena cava, the whole point is to actually, er get the block back blood back from other places such as your abdomen, your legs, pelvis, and, et cetera. So, what something that is very important in, er, the superior media sinum addition to these veins, er, is gonna be the nerves that pass through. So there's gonna be quite a lot of nerves, very common exam question that comes up, er, often in exams essentially gonna be diaphragm. So there's gonna be a nerve that supplies the diaphragm that it is called the phrenic nerve. You need to know for them and know their origins. So origin is C three C four C five. So cervical vertebra 3 to 5. So it could come up as a, a short answer question to ask you to name it and identify it or it could be in a, in a SBA as well to say? Ok, which one of the following innervates the diaphragm. So, um if you move on, we have um vagus nerve and thoracic duct as well, which are quite important. So, vagus nerve, OK. Can you guys tell me, I think it is already there. Not really. So, is vagus nerve, sympathetic or parasympathetic? So which one is it, is it sympathetic or parasympathetic? Which one do you think the vague nerve is? Yeah, absolutely. Um Yeah, well done. So it is parasympathetic. So it's the main idea is understanding what it does. So think of it as it is gonna slow your heart down, it's gonna constrict your um essentially bronchi. So um it is gonna be rest and digest as you guys know. So it is quite important to actually know the definition as well. So it could be asked in the exam to just define what is meant by parasympathetic and sympathetic and specifically in the a short answer question. The other thing that you need to understand from vagus nerve that is it will supply a lot of the um essentially organs that we call them viscera. So, viscera is the same as organs um in the thorax and abdomen, but also it is gonna innovate some of your larynx. So your voice box. So you will encounter two nerves that come from vagus nerve that are called the left and right, recurrent larynges, nerves So, what they do is essentially when the vagus nerve is coming down, um, we have two of them like everything else. We have two, we have a pair of nerves. So the left recurring laryngeal nerve from the left loop of the L. So, er, from the left loop of the vagus nerve is gonna essentially roll on there. The arch of the aorta come back up and go supply the larynx the right, a recurrent laryngeal nerve. On the other hand, it's just gonna roll on their, their subclavian artery and then come back up. So it's quite important to know their structure. They roll on there, which is, that could be a common exam question as well. So we have another drug called the thoracic duct as well. So, uh it looks like a vein but it's not a vein. So what it does, it just drains your lymphatic uh and it will just bring it to the vena cava. The other thing you need to understand about it is that it, it starts from your abdomen from a place called cen systen GYA. And uh it just comes back up. The other key information that you need to know is the fact that we have structure trachea and all of them are very close together with um esophagus and a vertebra. And what you do get is the division of that um trachea to go to your lungs. So, very common notice T four T five is a level of carina cartilage. That is gonna be the, at the point where your main bronchus divides to two. So, remember that. So can you guys tell me from maybe sessions below or anywhere else you've seen, have you encountered t 45 anywhere else maybe to do with your statum? Is there any specific name we call that? No, anyone knows. What do we call, what is the significance? Absolutely. Well done. So on. So spot on Atenol angle of Louis doesn't matter what name you remembered by spot on er they usually use a standard but good. So that's the significance. So you can see it's always good to make links. So think about the fact that what ca what does it relate to another like thing that you will help you remember it easier. So if we move on, we have a concept called pericardium as well. So pericardium is essentially the sac that will uh enclose your heart. So it has different layers. So we we have the fibrous and serous. So fibrous is more thick, it's outside, serous is more uh on the inside, it's not as thick as the fibrous layer. So the serous layer, as you might expect, it has two layers like uh the pleura. So it's parietal and visceral. So visceral means it's connected to the viscera. So it's the inner one. Parietal is the one that is out there. So it's not connected to the viscera. So as you expect from pleura as well in here between the parietal pleura uh or in here, um the parietal pericardium and the bits of pericardium, what you do have is a space and in body we don't really have spaces which are empty, er, with air, like the only space you do get really um that is quite big, is lungs. Um but in here, what we do have is fluid. So we call it er pericardial fluid. And essentially, one thing you need to understand is what is the nerve that innervates uh this like fiber sac. So it's the phrenic nerve. So the nerve that goes down to your diaphragm is the same nerve that innervates this, this does not innervate your heart, it innervates the pericardium. So just don't get it mixed up with the vagus nerve. So uh we have the heart surface as well, which is quite key to understand, to be able to uh visualize where the heart is in your body. So we have different surfaces. So as you can expect, we have posterior inferior, anterior and lateral surfaces. So from posterior surface, it essentially lies your posterior side. And if you think about it as the picture of I'm showing you here, that's how your heart is in your body. You don't really, you can't really see the posterior side of your heart here. But if you imagine what you can see is the right atrium at the a atrium at the right, you can visualize uh what is like pos posterior to that is just gonna be the your left atrium. So it's not like in real life that they would be exactly left and right like this. So they're a bit tilted. So uh also we have the inferior surface, so inferior surface is facing down, so it's facing towards the diaphragm. So we call it the diaphragmatic surface as well. So on that surface, what you do usually get is if you look at this, what you can't see is the part of the ventricle, that's uh the diaphragmatic surface, which is your left ventricle essentially. And what part of ventricle you can see here is your right ventricle, which you can expect it to be the anterior surface because it's towards you. And you can see er at the right side that we talked about it. That is the the right atria that's gonna be your right pulmonary surface essentially, which um essentially you might encounter. So this might not be the like best exam question, but it does help to visualize the heart quite well. So we are radiology society guys. So uh let's look at x-rays as well. It make it sound a lot fancier and you can visualize it better. So if you look at this, this is where your heart is gonna be on a chest X ray. So this is a normal chest X ray. So remember in a chest X ray, your right hand side. So the right, your right hand side is the left hand side of the patient. So you can see your right hand side, the left hand side is showing in the left ventricle and the left atrium. And you can see the left ventricle tilted towards the back, posterior side, but your right ventricle is tilted towards your anterior side. So you can see it and you can see essentially that's how you can visualize the four borders of your heart. So we have the borders as well. So you need to essentially understand er where do they start? Where do they finish in terms of intercostal spaces? So that's why we number the intercostal spaces because it's easy to know where things have been damaged or where things are. So it could just go down by intercostal space or the ribs and then say this is where it's gonna be. So uh heart has different borders. So the right border, left border and we have inferior and superior as well. So the main important ones are right border and left border. So the right border is gonna be from your third costal cartilage to the sixth costal cartilage. So it's gonna be just slightly towards towards your right hand side of the body because heart is mainly towards your right and it's just gonna extend down. But your left border is gonna be between second intercostal space to fifth intercostal space. So it's not gonna be between two costal cartilages like the right side. Well, how I used to remember it is essentially the apex is always at the f in space. That's where you hear the sounds, the best of the ap apex beats. So I used to remember that's gonna be there. And um second course of space was just three higher, same with 6th and 3rd, which are three different. So again, uh I remember it as you wish, but that's how I did it. But yeah, so again, it's good to notice because it can help you to know where to place your stethoscope when you wanna hear uh heart sounds and potentially like murmurs. So it is good to actually know how to interpret chest X rays as well. So basic instructions on chest X ray. So it could potentially come up in your exam. But uh it makes you a better doctor overall. So let's think about er sorry, let's go back to a slide 13. So by the way, guys, I hope you can all see the slides. I've uploaded the slides as well before the session. So if you can't let me know again in the chat, so I'll make sure uh to see what's the problem. But um if you can just stick to the slides you have. So we are on a slide 13. So if you look at the chest X ray, remember the right hand side is uh the left side of the patient So we are starting from our left hand side. So if you look at that black, so it's not really black. So it's a little bit darker and uh you can see the top left box. So what do you guys think that is? So it is coming down from your Pharynx. It's something that's coming down. It's not your vertebra to give you guys a hint. So that's not what we are referring to. Absolutely. Absolutely. Track you up, spot on. So good. What about uh the middle one on the left? So what do you guys think that one is? So you can see it's a junction. So something is entering. So what do we call that? Do you guys remember? Do you guys know? I mean, we haven't gone through it. Really? What do we call where they enter the lung? What is that called? What's that place called? It started with the H H I Absolutely. Well done. Smart. So, absolutely. So it's high limb of the lung. So specifically, er, this one's gonna be right eye limb, so it's our left side. So it's gonna be the right eye limb of the patient. Good. So if you move on now you're referring to the parts of the heart, so you can actually see heart quite clearly here, uh which is gonna be the part between your lungs, which is just a white uh sac and uh it shows that it's just made of muscle and you can see. So based on everything that we talked about the borders, the bottom arrow on the left. So our left, what do you guys think that's referring to? So, is that referring to the right atrium? Right ventricule, left ventricle or left atrium? So which one do you think is referring to? So, I, so that's the right side of the patient. Absolutely. Very well done. So, right atrium is absolutely right. So you can see that's the right pulmonary side. So it's towards your lungs. That's why we call it the pulmonary uh like surface and it's the right side. So it's gonna be the right atrium good this spot. So if you move on to the right side, our right side to the left side of the patient, what do you guys think the top right arrow is referring to? So it's a bit chunky but it's probably something that's come up because it's a bit whiter. So it's going up, do you guys know absolutely aorta? So specifically, that's uh most likely gonna be the arch of the aorta, but 100% right? So very well done. So always we most object l most um like m most things in our body. So most viscera in our body are gonna be kind of like mirrored, not everything. But now this is an example. So the second one from the top, so the second box from the top on the right side, that's gonna be a mirror from something that we talked about on the left side. So, what do we call that? It's where you enter the lungs again? Absolutely. 100% well done. So, it's, uh, this was, uh, left hilum. So I identified correctly very well done. So, now if you move down a bit, so we are gonna look at this. So the two boxes that we've got left, one of them is referring to one of the ventricles. One of them is not. So you might say, oh, is that referring to their left Atria? It could potentially be but not really in a specific case. Why? Because Atria is just positioned uh in a specific way that is just gonna be a little bit higher and towards the back. But what we are referring to is uh kind of like an artery. Uh If you look very carefully, you'll be able to be able to spot it as a little bit darker going back on the left hand side of your heart. So what artery do you guys think is gonna be that is going down from behind your heart? Do you guys have any ideas what it could be? So, I'll give you a hint. It's part of aorta good thinking. Ascending aorta is a good shout. But if we think about it, ascending aorta is gonna be higher. Why? Because we identified that the arch of the aorta is quite high. So you can see it's like close to your clavicles. But this one is quite low. It's below the ventricles at the like nearly bottom half of your ventricle, which I will personally look at it. It doesn't really look like ascending aorta to me. Yeah. Good job. So, Thoracic aorta is a good one. So descending aorta or thoracic either way is fine, it's very well done. So that's gonna be the structure that you can see good. So the last one that we've talked about, the last box is essentially just um gonna be your left ventricle that you can see. Well, good. Hold on guys. So now if you move on to a uh like a chest X ray, so different structures and a chest X ray that are not related to your heart. So these are, this should be quite easy. So if we start from our left side, so the top left from our side, what do you guys think that bone is called? So it's the biggest bone. It's not the biggest bone in your body, but it's a very big bone. Everyone can identify it on their own body. And yeah, it just goes to your humerus connected to your statum. Clavi ki very well done spot on. So, Clavi kill is the right answer. So uh then now uh if you move down to our second box, this is a bit tricky. So I'm just gonna give it away. So this one is referring to your scapula So why, why you might ask? So it might look like you're referring to the intercostal space, but because the scapular is just directly behind it, so that's what they're referring to. Um, you might be able to see some markings. Er, but again, it's more clear if you go a little bit too as your left. So if you move down now, uh to your left hand side, the bottom box, so that's gonna be there. Now, with our long is finished, you can see that dome shaped um like muscle, I would call it so fibrous sac sac or whatever you wanna call it that you can see. It's just uh the diaphragm. But what is gonna be under it is just gonna be an organ that's gonna be the organ that you're referring to. So what organ is on your right hand side of your body just below your diaphragm? That does a lot of jobs process as your alcohol. Good thinking a stomach is on your towards your left side. So stomach gets it from um your essentially um esophagus, but it's a bit towards your left side. But a good guess liver is absolutely right, very well done. So, liver is very towards your right and it's quite big and uh how you can detect it as well. Liver is quite big and pushes your thorax a bit up. So if you look at this picture, this x-ray, your right hand side is a bit pushed up. So that's how you can see. Oh that's because of liver. So liver is gonna be the object that's gonna be there. So now if you look at the left as the left hand side of the patient, now, right hand side from the bottom image, bottom image, you're absolutely right. So that's gonna be your stomach. So that's where your stomach is gonna be towards your left. But you can see some uh some other stuff as well below your diaphragm. So they're kind of like bubbly. So we call them um essentially um like essentially bubbles like that you would be able to see. So gastric bubbles that you would be able to see on an X diagram usually because of air uh which they're quite common. Uh They're not like anything like medical, I mean, um as long as they're not huge and uh the left one at the top is just referring to spinus process of uh your vertebra. So very well done guys for having you go at it. So it is quite difficult, but now you should hopefully be quite confident at interpreting the basic structures. So if now we move on a little bit to the coronary arteries. So coronary arteries important to understand we have the right coronary artery and the left coronary artery. The right coronary artery mainly supplies your right hand side of the heart, left coronary artery, mainly, not all, not all like you would say, just just the left hand side, mainly the left hand side of your heart. So the left um coronary artery, the main branch that comes from, it is left anterior uh descending. So we called led something called it anterior interventricular artery, which is the exact same thing. And it gives rise to other branches like the diagonal branch, which what they all do is they supply your left ventricle and part of your right ventricle. So we have the left circumflex artery as well. So left circumflex artery supplies your left atrium. And that's his main job. It gives rise to some other minor arteries as well. And other thing to mention as well that the left coronary artery comes from the left main stem. So the left main stem er divide to circumflex and uh L ad essentially. But on the right hand side, you would usually see some branches that go to atrial var node and sinoatrial node. So for the pacemaker, some branches that go uh like to your what we call the poster interventricular artery. So the posterior descending artery, so it supplies uh your right ventricle and part of your left ventricle, which is quite important and uh we have right, marginal as well. So right, marginal, essentially, uh supplies the inferior surface of like right side of your heart. So like your right ventricle essentially. So we have so a concept called left dominant and right dominant. So it essentially means where does the er posterior interventricular artery arise from. So, if it arises from right coronary artery, it's called right dominant. If it arises from the left coronary artery, we called left dominant people. So which one do you guys think is gonna be more common? Do you think more people are right dominant or do you think they are left dominant? Any ideas? Good. So you think that your er posterior interven card artery is more likely to come from left, which is a good guess. But actually, it's the opposite way around. So it is mainly coming from your right hand side of the body. Why? Because think about it as uh mainly because of evolution, the left anterior descending is already calling coming from your left side anyways. And it's supplying your er left part of the heart like left ventricle. If the right, like the right postero ventricular artery also comes from the left side. What happens is that both of your ventricles will be supplied by the left coronary artery, which could be more dangerous. So, if the left main stem gets blocked, now, you would lose access or supply to both of your ventricles, which could be catastrophic, but more people are essentially right dominant. So they can actually supply part of both right and left ventricle via the right coronary artery. And er, if the left coronary artery gets er occluded, then there's less chance of, I mean, er, it depends, but the tissue dying potentially so it is better to be right dominant and yeah, so this is essentially the clinical significance of it as well. But good stuff guys. So you don't need to know much about cardiac veins. To be honest, you don't need any, you need to know one fact, this is not very high yielding exam, but it's good to know. So there is all of the veins come together, they drain into one main vein that goes to your right, takes all of them back to your right Atria. So I've just put a box there. What do you guys think that main vein is called, that goes back to your right, right. Atria. Do you guys have any ideas what to be called that any ideas? So we call this sinus by the way because it's not, it's kind of like a big place that it's like a sinus. So a lot of blood essentially comes there gets accumulated and then goes back to your Right Atria in simple terms. So we call it the coronary sinus. So coronary sinus is the only thing you guys need to know is where all of the chronic veins drain and then there's coronary sinus just drains into your right Atria as well. So good stuff. Uh let's move on. So we have different structures of the heart as well that you need to be aware of. So we have the atria and the ventricle. So in the atria, we have different structures. So we have muscles, we have different tendons that you need to be aware of. So let's just think about it in Atria. I wouldn't ask you guys by the Atria. We have something called Crista terminalis that is a muscular ridge that divides your posterior side from the anterior side essentially. And then there is some uh some other things that are coming out of Crista terminalis as well that we will talk about in a second. But if we move on, we have some valves. So uh going down from your right atria to your right ventricle. What do you guys think? So it's just the right top box. So the left top top box, I apologies guys. So um between your right atrium and your right ventricle, what is that um valve called? So what do we call it? So we have 22 valves, two ma I mean, we have more than two valves. So we have the aortic and pulmonary as well, but we have two main ones that separate atria from ventricles. So which one is on your right side of the body? Absolutely. It is your tricuspid, very well done, so, very well done. So 100%. So if you move down a little bit, you guys can see to that trichopi valve, there is some essentially bands being connected that they connected to a muscle. So what are those bands called? So what do we cause those? So they're kind of like a tendon that they just connect their muscles, er, back to their, a, like essentially a not aortic apologies, er, to the valve. You're absolutely right. So it's called a Tendinae. So it's spot on. So that's what, er, will estil your, er, valve. So it makes sure that it like pull the thought when the pressure is very high. So that's how, like you get the connection good. So what do you think the muscle is called? So it's the left bottom box. Like you guys can see there's muscles, there's three on the, on the right side's spots on. So there's papillary muscles very well done spot on. Um and then going back to it. So we talked about cry notice at the atria as well. So the muscles there are called pex muscles, but the muscles in your ventricles are called papillary muscles. It's a very good job guys. So if you move on to left uh side of the heart, so your right hand side, you'll be able to see that we again have different structures. So, uh we have something called a moderator band that connects your papillary muscles to the septum. What do we call um, a valve between your left atrium and left ventricle? Anyone has any ideas? What is that valve called? So the right one is called Tricuspid. What do we call the left valve? Absolutely. So it mitral well, very well done. So by cos some people call it, but mitral is absolutely right. Very well done. So, we are gonna understand heart sounds as well. So it's quite important because it's quite practical stuff. So, if you look at uh, your right hand side of your bo like your heart and left hand side of your heart, you're gonna have essentially two sounds from each. So you're gonna have from atria and your ventricle, um, not atrial and your ventricle, sorry from your uh essentially between your atrial and your ventricles. There's gonna be one sound. So, er, like the valve between them and there's gonna be one between your ventricles and your arteries. That's gonna be the pulmonary and the aortic valves essentially. So when you, when do you hear the sounds when they're close? So when they open, you don't hear anything when they're close, you hear a sound, that's what you're hearing. Um And also you need to understand where to put your stethoscope to get the maximal uh sound. So, for your aortic valve, you need to put it in your second intercostal space, uh exactly towards your right of your sternum or for pulmonary, you have to put it second intercostal space towards the left side of your sternum. I personally thought that it was the other way around, but the aorta doesn't actually, it does come from the left side of your heart, but it actually pulls around and goes a little bit towards your right. So that's why you can hear it better towards the right hand side later mirror. But the tricuspid now, uh it is just gonna be a little bit towards right hand side of your mitral valve. So you hear your mitral valve at the fifth intercourse of space, mid clavicular line. So a line down the center from your claviculus and that's gonna be exactly where you hear it. So exactly in the center and trichotomy is gonna be just a little bit towards the right. So it's still on the left hand side of your body because heart is towards that. But again, it's just uh left of their standard of a little bit of fifth in circle sort of space. So that's pretty much everything about the structures. Uh Now we can move on to the conducting system of the heart. So it is quite important to understand seal sinoatrial node is essentially the pacemaker cells er that are at the border where your superior Vena cava comes. I mean, the Vena cava comes to your right atria and that's essentially gonna be where the pacemaker is located. It sends out the signals and then atrioventricular node is gonna delay it and then send it back down uh towards the septum. And it's gonna go through first a bundle of his, it's gonna divide to two branches called the left bundle branch, right bundle branch. Then it's gonna go down your ventricles and come back up and we call it the purkinje fibers those fibers that come back up, something called pine, something called pini, either one is five. So innovations are very, very important. They're very high yielding exam. So you need to understand them. So sympathetic um innervation of the heart is cardiopulmonary splanchnic nerve, which is again, uh a mouthful. You don't really uh like hear from it much, but it's quite important. So, have you guys heard about the terminology that we called inotropic and chronotropic? And if you have is sympathetic nerve, gonna be positive inotropic or negative inotropic, any ideas? Which one it could be any ideas? So, app isotropic and goo TriC refer to increasing your heart rate and increasing the strength of how much your heart is beating. So would you think your sympathetic nervous system is gonna increase that? So it's gonna be positive or do you think it's gonna decrease it? It's gonna be negative? So I just rephrasing the question, is it gonna be positive inotropic and colono tropic or is it gonna be the other way around? Any ideas? Absolutely fine guys. So it is gonna be positive. So positive inotropic and goo TriC means it just increases your heart rate and er the force of contraction. So you get more um blood pumped out. Why? Because sympathetic nervous system usually gets activated when you're in a like essentially fully advert um danger situation. So you want to make sure you're pumping blood effectively towards your muscles. On the other hand, we have the vagus nerve, which is parasympathetic. So it does exactly opposite. So it's negative inotropic and colonic and vagus does supply um other viscera as well. So, we have something called referred pain. So, referred pain could essentially come up as um not usually in phase one, but again, it could come up as a stem uh of a question. So, just explaining that a patient had a referred pain, but what they essentially mean is uh the pain radiates somewhere else. So, or the pain is not essentially coming from er, where you would usually imagine it would come from. So you might think your heart pain might be central on your chest where your heart is. But some people get it on the shoulder and you might think why is that? So, the reason behind it is because uh the dama terms of like over your shoulder and your hands and a little bit of your neck, um those dermatomes go back to the same spinal nerves that your er s somatic sensory nerves coming from your heart go to. So your brain can't distinguish which one is alarming you. So it would just essentially give this pain signals back to all of these dermato because it can just distinguish, but it is um quite good to understand it. Um just in, just because you'll see it later on in questions as well. So to just give it a little bit more context and we've put some cases here. So, imagine this was a patient that was admitted to emergency. Uh, they had shortness of breath and they had swelling in the legs and they were really fatigued. They have hypertension as well. And history of like, uh, heart disease, ischemic heart disease specifically. And they have, er, so they have like, essentially edema in the legs as well. So there's fluid accumulated there and their BP is quite high and the heart rate. Um, yeah, I would say it's quite high as well and you order investigations as a doctor. So you get a blood test that tells you something's elevated. You might, you guys probably have not heard of BNP, but it's just, er, coming from your event because it just shows damage and you see this chest X ray as well. Firstly guys, does this chest X ray? R look normal to you? So when you look at this, would you say it was the same as what we saw before? Absolutely. I would agree someone. So 100%. So what can you see which is wrong with this? So, what about the heart? Can you see that you couldn't see on the normal chest X ray that I showed you guys? Is it bigger or smaller? Absolutely. So it's very enlarged. Absolutely. Annabelle. So very well done. So it is very, quite enlarged. So that's a big trigger as well. So this one's a very severe case that does essentially uh lead to the diagnosis of heart failure. With addition of all of the info that we have and also the blood test. So the essentially how you identify heart failure from x rays are you might see some pleural effusion. So some fluid coming out to the pleura where it's not supposed to be that shows edema. Um we have cephalisation of vessels as well. You guys don't need to really understand what that means. You do it later on. And essentially the main thing is just the cardiothoracic ratio has gone higher. So the heart has become a lot bigger. So now we can move on to a little bit of your thorax. So the bones are quite important. You need to be able to identify this maybe on yourself as well. So what are the three main parts of your sternum? What do we call those three main parts? Any ideas? Absolutely marium body enzy for process the spot on guys. So it's good to know them. Then if you move on to ribs, the ribs do connect to them. So they're quite important. So, uh there's different classifications of ribs. So some of them are called true ribs. So 1 to 7, why are they called true ribs? Cos they're, they're complete, they come from your vertebra completely to your sternum. So 8 to 10, we call them false ribs. And why? Because they just completely float from the seventh rib. So they're not originally coming from, directly from the sternum and the 11th and 12, waves are called floating. So not connected to sta at all. So that's why we just call them floating. So you have different joints as well. So the costovertebral costochondral joints, the costochondral joints is a joint between costal cartilage and your ribs. And costovertebral is between your ribs and your vertebra. So try to always make sense of the stuff before memorizing it. you need to understand the attachment as well. So the head of your rib is er gonna attach to the body of your vertebra. And the transverse er process of your vertebra is the part coming laterally. It is gonna er attach to your tubercle of the ribs, er rib as well. But again, it's not the most common exam question but make sure you understand and visualize why this is the case. So in terms of surface anatomy, like it's good to know where these lines come from. Not necessarily come up in exams, but mid axillary, anterior axillary and posterior axillary lines are gonna be if you just look at your axilla, if you draw a line, middle posterior and anterior side, that's gonna be the line. So this could be useful when you are referring to where uh an injury is potentially located. So in medical terms, you can describe it via uh these lines, we have other lines as well. So we have mid clavicular as well and midscapular. So essentially imagine halving your scapula and also your clavicle and drawing the line straight down. So you need to be able to identify a lot of these structures that we talked about on yourself um which are not really hard to identify. So if you move on to breast as well, so there's a lot going on with breast. But honestly, at this stage, the most important things are these two dermatomes know them. So the nipple area areola is gonna be around dermatum T four. Mius is gonna be T 10. So know these two and that we talked about before as well. I know the blood supplies as well. They're quite uh common so they can come up with exams. So internal thoracic artery uh is essentially an artery coming from a subclavian artery. It's just gonna be the medial side. It's gonna be here. It's gonna supply parts of your breast and you're gonna have the axillary artery. So axilla from your axilla, just gonna part, supply the lateral sides of your breasts as well. So there's five different uh lymph nodes that you see their names all over the place in your axilla. Don't need to really know the name of them. All of them don't really come up in exam. The only one you do need to know about, which is quite important is apical node. Why? Because every other one drains into the apical node. So it's a central place to look for any conditions, for example. So it's quite important to know it. So now if you move on, we have different muscles as well. Um So you just need to be able to identify them. So they could give you a picture or er, they could ask you about the innervation essentially. So we have pectoralis major minor serratus, anterior. So pectoralis major is the most anterior one. So um what you can see is connected to the first top six ribs is connected to your scapula and your clavicles. But your pectoralis minor is just gonna be a little bit deep to it and it's a lot smaller as well. So it's only connected to ribs 3 to 5 and there's a little bit of your shoulder blades or scapula and s to anteria is just gonna be towards your sides and it's just gonna be connected to the top eight ribs essentially. Um You'll learn more about them when you do upper limb as well. Don't worry about their innovation for that. So, intercostal muscles as well, they're quite important. So we have innermost internal and external uh intercostal muscles. So external intercostal muscle, I always used to remember that. Imagine you've got a pocket you're putting your hands in. So external intercostal muscle is like this, it's going anterior towards the center. So imagine if it has when it's contracting what it does, it contracts up like this because these muscles are going that way. It just contracts up So it's used in like mainly active, essentially in inspiration. We have the internal intercostal muscle as well. So they're perpendicular to it. So you can see that this way. So when they do contract, they pull it down. So they actually reduce the volume of the chest. So you, they are mainly active in inspiration, er expiration, sorry. Um Yep. And yep, innermost as well. So innermost are parallel to er internal intercostal muscles as well. So, pleura as well is just good to understand what it is. So uh we have different pleura, so we have pleural sac. Uh So we have parasal pleura, uh visceral pleura. So visceral connects to the viscera. So to the surface of the lung, parasal pleura is gonna connect to uh the surfs of your thorax essentially and you're gonna have a fluid between them and we call them uh the pleural fluid. Essentially, there's different classifications, not really high yield in the exam. Um We have something else I might encounter that people don't really understand. Have you ever heard of Costa Media style and cost informatic recess? It's not a very common exam question. Just people get confused about it. Have you guys heard of it? Do you know what that is? Ok, good. So you've had it. That's good. So essentially the space between, so ca er Costal media style. OK. That's good. So I guess so we go through it, don't worry. So er Costa media style is gonna be cost. Costo essentially comes from your ribs. Um and media style comes from your heart. So costo media style is just ap a little bit like it's not a big pouch. But again, where a, a little bit of your fluid is gonna be there, it's just gonna be between the media sinus sur surface of your lung and your heart essentially co the diaphragmatic is just gonna be between um your diaphragm and your lungs. Essentially. There's just gonna be a little bit of space that's gonna be fluid between them. But the more important things is lungs. So it's quite important to understand lungs. So there are different surfaces. The costal media style is diaphragmatic. You can tell diaphragmatic surface is inferior surface, costal is towards your ribs. So front and media style is towards your uh heart. So the main important things it could come up in the single best answer and it could come up in short answer the question as well. Just ask you to identify structures or name structures, potentially of the lung or main name the differences, potentially. So the main difference is that the right uh lung has three lobes, the left lung has two. So because of that, that means there is two fissure. So two lines that separates everything on the right side and there is one on the left because there's only two lobes. So we call that the oblique fissure oblique because why it's just, it's not horizontal, it's going down. So it's in both of them that separates superior from inferior, you have horizontal fissure as well only on the right uh lung, which is a good exam question, but that separates the superior from middle lobe of your right lung. The other thing that you need to understand is where these lungs finish in terms of your ribs. So, er lungs, in terms of your, in er, like anterior surface, they finish at your sixth rib laterally, they finish at eighth rib posterior at 10th. So that shows you that actually the posterior, it is a little bit, little bit bigger than your anterior side, but actually the paal pleura extends a little bit lower. So add the two to each of them anteriorly. It goes to eight later into 10 posterior to two. Why? Because there's fluid between them and there's just a space, you can just squash them all together. So let's talk about innovations as well. So, uh we have autonomic uh that essentially innervate the lungs that a again parasympathetic and sympathetic. So, for a parasympathetic, uh what we do have er, is what it does is like uh concentric of bronchial muscles and for sympathetic, it's just do, does the opposite. So it's gonna be bronchodilation. So, uh lymphat lymphatic system is quite good to know. But again, er in Sheffield, they don't like ask too much about their lymphatic system. So, if we move on, this is a very common exam question that they put in. So the the high of the lung where everything enters or gets out are the main, essentially uh things like the bronchus, uh the pulmonary artery and the vein. So the main main thing you need to understand is called R. So your pulmonary artery on your right high limb is gonna be anterior to your bronchus. So your towards the front on the left bronchus, it's just gonna be superior. So right, anterior, left superior, that's the acronym that you need to remember. So you need to understand bronchi as well. So the structure of bronchi, so we have three lobar bronchi on the right side and two on the left and then all of those lobar bronchi, so that they are essentially divisions of the main bronchus. They essentially go to 10 segmental branches on both right sides. But you might, you might ask why three on the right, two on the left because we have three lobes on the right, two lobes on the left. So you can see everything you know, to be relates to other stuff. So if we move on to diaphragm, so diaphragm is just a sheet of skeletal muscle and uh towards the center, it's essentially not a muscle. So it becomes fibrous, we call it central tendon. So a lot of things get inserted there. And do you guys remember what is that nerve that in rates? Phrenic? Er Sorry, I just said it. So, phrenic nerve is just a nerve that innervates the diaphragm. So, er, absolutely. So, it's a common exam question. You need to know it. The other thing that you guys need to understand is that the diaphragm, there's gonna be different structures passing through and at what vertebral level do they pass through? That's a common exam question at vertebral level. T eight, Vena Cava is gonna pass through at vertebral level. T 10, esophagus is gonna pass through at T 12 aorta is gonna pass through. How do you remember it? Vena Cava is eight letters, T eight, esophagus is 10 levels and 10 letters T 10 and the other one is left is aorta. So let's quickly talk about breathing and uh we'll do some exam questions and hopefully finish off quite soon. So, um what we do have is we talked about the actions of uh your acceler intercostal muscles and your diaphragm. So, acceler intercostal muscle pulls it up, pulls your chest up. Diaphragm contracts a as like a dome goes completely down. So this increases the volume of the lungs and more air moves in. Essentially the other way when you are expiring er in expiration, what you do get is the opposite of it. So, inspiration is quite active. Why? Because you have to contract the diaphragm, you have to contract the external intercostal muscles, but actually normal breathing. If I'm normally breathing, do you think expiration is gonna be active as well, or do you think it's usually because of elastic recoil? Any ideas? Any ideas? So it is actually because of elastic recoil mainly. Why? Because the diaphragm just relaxes, it just goes back up and, er, but if you do need more force as well, internal intercostal muscles can essentially contract to put it all down. But again, it just depends, the other good thing to know is accessory muscles of breathing. So, if a person is under dis respiratory distress, they would need these four muscles uh to actually help them breathe better. So, mastoid pectoralis, major, minor serous an area. So chest muscles that will usually help move your arm will actually help you breathe. So, uh OK, guys, let's just look at the X ray uh very quickly. If we just look at the X ray, does this look normal to you guys? And do you think is there anything that you can tell me about this x-ray that doesn't look normal to you if it doesn't or if it doesn't look normal to me? Let me know. Does this look normal? Do you? Yeah, absolutely. So it's abnormal on the right side? Absolutely. I would agree with you. Liquid on the right side 100%. Why? Because it's white, it's not supposed to be white. Um You can see in, in your um lungs, it's usually made of air that makes it a little bit darker. But you can see there's a lot of fluid, so collapsed lungs, it could be. So, um in this specific case, the left lung hasn't collapsed yet. And the right lung um is probably about to collapse if it is, if it goes untreated. But again, it depends on the patient. So I would agree with you collapsed lung could certainly be on your differential. And absolutely. So you guys can see there's a pleural effusion, that's what we call it. So it's in your effusion, it's just essentially like fluids uh going out to that place and pleural is between your pleura. So it's spot on. So why does this come from? It does, it can lead to like collapsed lungs because it reduces the surface tension, which in this case, it potentially could have. But the main reason if you read the case here is a patient has shortness of breath, dry cough, um high BP, low saturation. It's just because of the fact that uh they've had essentially a heart failure. Why? Because when you do get heart failure, your heart doesn't pump anymore. So fluid gets er like fluid just stays in a place and then heart right to pump and all the fluid is trying to come back. So pressure builds up, pressure leads to fluid leaking out to spaces where it should not be, which leads to this specific example. So when you are trying to interpret x-rays, always look for anything that doesn't look normal. So if you look at the chest and you know how it looks like, look for any deformities, any different colors that could guide you very well done guys. So we have got some exam questions and then we'll finish off. So now we have a patient that is under respiratory distress and that means that when they sat down, they're using external muscles for breathing. So which of the following muscles is an accessory muscle of breathing. Is it external intercostal muscle, internal intercostal muscle, external Clamato or external oblique? So which one is one that we talked about uh for to be an accessory muscle of breathing. And also remember usually questioning your exam do have a clinical stem. So that's what I've tried to do a very short clinical stent. It doesn't necessarily need to be relevant. You don't need to know much about it if they mention a specific condition, but it gives it context. So which one do you guys think is gonna be? So internal intercostal muscle? Good guess. Is anybody else, does anybody else agree with it or disagree with it? So the is c so it's AOM mastoid, you are close, but actually internal intercostal muscle, external intercostal muscles are actually a accessory muscles of breathing. Their main job is breathing. So, accessory muscles of breathing are the ones that help breathing uh when like you are in distress. So standard the mass. So it does help it but doesn't usually involve it. So that's why you uh get it as an accessory muscle of breathing. But good guess. So if you move on now, uh which of the following is found in the middle Mediastinum? So they might ask you to identify certain structures. So which of these do you guys think is in the media? Medi medi Mediastinum, is it the aorta thymus heart or a vein? So think of it as what was in the middle Mediastinum, what was the barrier? So what would be there? Do you think? So, mainly we talked about in terms of heart? So heart is gonna be mainly there. So what other structures could be also that or would it be just hearts or am I just misguiding you guys? Absolutely. It's hot. So I have a good guess. Thymus is good. So I've seen in the anatomy pan book once they refer to thymus being in um essentially er like inferior mediastinum. Once in being superior Mediastinum, it's certainly not in media mediastinum. If it was gonna be, it would be in anterior because it's not gonna be close to your heart, but it's actually usually in the superior mediastinum. Um it, it varies between people but it's gonna be used in the superior mediastinum. But good guess. So, heart is the one. So aorta you could potentially uh counter by this very um it's very broad. So I would just say ascending aorta, you could count it in but not just aorta, but heart is the right answer. So, very well done to anyone who got it good and as it gets very, it's gonna be in posterior mediastinum. So it's just gonna be towards your vertebra. So behind your heart. So now diaphragm is a muscle involving inspiration, which one of the following nerves innervates the diaphragm. Is it vagus nerve, accessory nerve, glossopharyngeal nerve or phrenic nerve, a guys very well done. 100% right. So phrenic nerve is the right answer. It's a good exam question. So now we know that patients are admitted to the hospital with cough and chest pain and the doctor uses a stethoscope to listen to his heart sound. And where should he place his stethoscope to actually uh hear the aortic valve sounds? Is it the second intercostal space? Fifth intercostal space? And where is it gonna be a, we've got an option for a anybody else wants to go for it? You're absolutely right. They well done. I'm going to run for b very close. So it is second intercourse of space. Actually, your aortic is gonna be to the right of your sternum. Why? Because we talked about it as your heart, your aorta is just gonna loop on there and go towards your right side a little bit. So that's why you hear it better on the right side of your sternum and not the left side. It would be logical, but it's the way that is set. But good. Good guess this guy is very well done. Last question, which of the following is found in ventricles. Is it pectic muscles, papillary muscles, fossa, ovalis or pacemaker cells? We have one testing for B papillary muscles. Good. Anyone disagrees absolutely fine guys. Well done. So, papillary muscle is right. So the rest are found in your atria. So thanks guys for listening. Um So we've hopefully finished on time. So let me know if you guys have any questions, we've covered quite a lot today. So uh let me know if anything doesn't make sense, you want me to explain something again or? Um Yeah, any questions that you might have, I'll be able to answer. So feel free to do the feedback form that should be sent to you guys. So you'll get a certificate and a good for your portfolio as well. You're welcome guys. Absolutely fine. My pleasure. So let me know if you want me to do something differently in the feedback form, always put it there. If you want me to continue doing this stuff again, put me, put it there as well. And yeah, so if you have any questions, let me know, I'll stick around for a few minutes for anyone who has any questions. Feel free to unmute yourself or put it in the chat. Absolutely fine. OK. Thanks guys.