what's up everybody so in this video we're going to be talking about everything that you need to know regarding transport and no this is not the kind of Transport as in flying running taking a boat trip it's not this kind of Transport unfortunately this is the kind of Transport where we learn about how things are transported in our body how nutrients go where they need to go how our oxygen goes where it needs to go this kind of Transport is what we're talking about so this will have two sections we're going to first focus on transport within animals and then we're going to go on to talk about transport in Plants okay so that's what we're going to be covering in this video so let's just get started so like I just said we're going to be learning about transport how things are moved around our body now in our body we have so many systems right including our cardiovascular system our respiratory system our immune system our digestive system so many many systems and each of them have their own role now the cardiovascular system is very important in this video because this system is responsible for moving everything where it needs to go inside our body okay so we can break the word down cardio vascular system cardio refers to Heart and Vascular refers to our little vessels all the pipes inside our body and then inside these vessels inside these pipes we have blood right so red blood cell white blood cells nutrients oxygen carbon dioxide many many things dissolved in our blood so the combination of these three things make up our cardiovascular system which is responsible for transport so I want you to understand now also that each of the systems in our body don't work in isolation they depend on each other a little bit so an example is our cardiovascular system depends on our other systems for example one one you need to know about is our respiratory system so when we open up here uh Eddie Hall the World's Strongest Man we look at his lungs and his heart and we see here okay so out here in our chest we have the lungs uh we have these pipes that lead to our lungs called our tracha and our bronchials right you learn about that in the respiratory system video and situated in between our two lungs we have our heart normally our heart is actually the shape of our fist like a clenched fist so this is obviously exaggerated unless you got a huge hand or something now like I said these two body systems work together so how our respiratory system is going to be responsible for bringing air such as oxygen inside our body inside our lungs and then putting that air into our bloodstream okay into our bloodstream now our cardiovascular system is going to help us distribute that blood which contains nutrients and oxygen to all the cells of our body because if we can keep our cells healthy and happy then we will be alive we will be healthy and happy okay now it's important for us to understand how our cardiovascular system looks like so let's go take a look at how it looks like so let's say we have our heart here how are all the vessels uh linked to the heart and where are they all going what's the whole circulation deal so I'm going to show you a simplified diagram here of what you need to know about this circulatory system okay the cardiovascular system so in the center here we have our what this is our heart you're gonna there's going to be a video where you guys learn a lot more details about the structure of the heart the whole um exact details of the circulation for now it's just to understand the overview because in this video we're really going to focus more on the vessels so we got our heart here and it's the pump it's going to be the machine that's going to pump that blood across our body so first our heart is going to start and it's going to pump blood into this little vessel this vessel here okay we call that an artery an artery specifically we call it a large artery okay because they're attached to the heart and they're quite big now the condition of our blood here is important to understand so the blood here that is being pumped away from our heart um in this scenario here will have a lot of oxygen they're nice and fresh and it's got low carbon dioxide okay so very important this is the kind of blood our cells like it likes to have a lot of oxygen because we know we need a lot of oxygen so we can do self respiration and make ATP and same goes for low carbon dioxide so this fresh blood is being pumped out of our large artery and then we know these arteries will Branch into smaller arteries Okay small arteries and then they'll continue branching and branching till they become such small arteries we call them arterials arterial so a small artery is just called an arterial and then it gets Branch so small that we reach a destination which we call the even smallest little vessels called capillaries Okay so what we have here is our heart is pumping that that fresh blood all over our body our lower body our upper body any cells that you can think of that needs this blood that needs this blood so it's being sent large artery small artery arterial and finally capillaries these are such small vessels now the capillaries are special because these um are the vessels that are responsible for um these are the vessels where the nutrients and the oxygen can leave the bloodstream and go to our cell right so at the capillaries we have a lot of cells that need the oxygen and nutrients and all that so the capillaries is nice and specialize because they are the place where this blood can actually leave and go to the cells okay that's important to understand that's different from these large and small arteries they are not allowed to let the blood leave only the capillaries are so the capillaries allow this oxygen to leave and go to the cells and the cells can use them now for whatever they need to and at the same time the cells here can make waste like carbon dioxide and things like that now this waste is going to be sent into the capillaries so that they can be taken back to the heart so the blood coming out of here from the capillaries we can consider waste blood because it's not fresh anymore all the cells here drained this blood from the capillaries and used its nutrients and oxygen and now gave it back waste so the waste is now coming back into this little vessel here which we now call a venu this is a small vein and this small vein the small venil will drain into a bigger venules and bigger until we have the biggest veins okay so a venil is just a small kind of vein so they drain out here now the blood here important is waste blood so we can consider this kind of blood to be low in oxygen why because these cells here around the capillaries sucked out all the oxygen from this vessel here from the capillaries here and gave back carbon dioxide because we know carbon dioxide is a waste product from from cell respiration when we try and make ATP so this Blood here will now be the opposite low oxygen high carbon dioxide we don't want this in our body okay we don't want the high carbon dioxide in our body and we want we want more oxygen okay so now it's coming back to the heart and now the heart cannot just take this blood and repeat the cycle it can't just take it and pump it back because this blood is dirty it's waste blood if it sends it now to the cells it'll be useless because there's no food there's no nutrients there's no Oxygen in there it will be useless so the heart first has to do something else that's very important and that's why I keep emphasizing that our circulatory system is closely related to our pulmonary system or our lungs our respiratory system because now this heart is going to take this blood that is waste blood in a way and it's going to pump it out this vessel here towards our lungs okay our we consider this our pulmonary circulation okay and this right here is our systemic circulation it's sent across our whole body and this system is here just between our heart and our lung so it takes this blood and again remember what's the condition of this Blood it has low oxygen high carbon dioxide right it came from here it's taken by the heart now it's going to get pumped to the lungs so first it sends it out this artery okay and again the arteries most close to the heart are considered large because they have to they're one of these big branches coming off the heart and they will branch and branch in in the lung to smaller arteries and then again the smallest ones the arterials and then finally what do we have here again our capillaries now what's special about the capillaries again these are little vessels that allow these gases and nutrients to leave and um to exit and enter so here what's going to happen is in our lung in the capillaries the uh carbon dioxide is very high so here at these capillaries they're going to leave because we want to Exhale them right we want to remove them from our body so they're going to exit into our lungs into our alvioli and we're going to Exhale them and at the same time here oxygen from the Alvi is going to enter all right cuz the capillaries are nice cuz things can exit and enter so our high carbon dioxide is going to leave and oxygen is going to come in because our oxygen is very low so that means now the blood draining out of this capillary will be what we call it the blood draining out will now have give me a second we have high oxygen and low carbon dioxide cuz we just entered oxygen and kicked out oxide so now this blood is full of oxygen again ready to go okay but again first let's let's come back here the blood draining out we're going to call them venules okay venel and it's going to drain into bigger ve bigger veins and bigger veins and so on back to the heart okay that's very important to understand so we need this is all a lot I understand but we need to now Define what an artery is what a vein is cuz it looks like a mess I agree okay so let's let's break down three key points you need to understand the first one the big brain tip Uno okay Spanish for one in case you didn't know Uno so what are arteries arteries are these vessels vessels these pipes that carry blood away from the heart veins are these vessels that carry blood towards the heart I know that's not how you spell two words but just understand that this helps you remember it okay so very important so let's look at this diagram again here the blood was pumped away from the heart so we call this vessel an artery an artery and then the blood coming back towards the heart in this vessel we call this vessel a vein because it's going towards the heart now again here this dirty blood was blot back to the heart the heart is going to go send it to the lungs so the lungs can clean it up it sends it out by this vessel which is going what away from the heart so we call it an artery and then again it gets cleaned up here in the lungs it gets brought back now it's fresh fres blood this this vessel coming back towards the heart we call them what a vein because it's going towards the heart so that's big brain tip Uno so very important let's look at big brain tip two or dose so understand this what are the colors so don't get confused by the colors red does not mean artery it's only an artery if the blood is going away from the heart so you can see here although here it's red although here it's blue they're both arteries okay so what is the deal with the color here so the color here is represented by whether or not the blood is high in oxygen or not whether the blood is fresh or not so this Blood here is fresh right it's got a lot of oxygen ready to give to all the cells so because it's got a lot of oxygen we're going to call we're going to make this we're going to annotate this artery as red okay so therefore it's red oxygen rich this one here is blue because there's no more oxygen oxygen is low it has just been used by all the cells at the capillar therefore it's blue now this heart is going to take this blue blood that's low in oxygen pump it to the lungs because it's still low in oxygen we make it blue okay and then it gets cleaned up here by the capillaries where oxygen goes in and carbon dioxide comes out and now it leaves and now it's fresh now because it's fresh it's high in oxygen it is now red again so know that these the color is based on oxygen level if oxygen level is high The Vessel will be red if it's low it will be blue okay that's very important to understand so don't get confused this is our last tip here our big brain trip t that's hard to say big brain tip tress the identification artery or vein is not based on the level of blood oxygenation hence the color it's not based on the color okay it's based on whether it's going away or towards the heart make sure you understand these big brain tips and they're very important to understand so I hope this makes sense so this right here is our circulatory system how it works okay hope it makes sense so now we're going to take a deeper dive and actually look at these vessels the veins the arteries and the capillaries these three key kinds of vessels and look at their structure how they're different because it's very important to understand that oh yeah by the way so in in like real life if you really look at an artery so the oxygen right is what makes the blood red it's actually when oxygen goes into your blood that makes the blood appear a bit red so veins are never as bright red they're really dark they're not actually this blue if you look at a real vein inside your body it's just easier for students to understand the difference but in reality the real um arteries and veins are more similar in color the arteries will be very brighter red they'll be much brighter red and the vein will be much more dark it won't be as bright okay but it won't be light blue like this okay just make sure you understand that but it's don't worry about that okay so now let's go and dive it take a deeper dive into these three kinds of vessels arteries capillaries and veins okay so here we have a nice zoom in of one of these little capillaries okay so you can see so let's label some things it's very important for us to First understand structure and then we're going to talk about function if we understand the anatomy how the things are working here then we can look at the Fun uh the function it will be much easier to understand so again simplified diagram here we have our heart it's pumping blood away from the heart so what do we call that an artery any vessel going away from our heart is an artery a for away yeah V for TOS so it's going away so we call this an artery so let's label some things of this artery so we can see here there's a bunch of layers of cells right remember just like our whole body our little vessels are also made up of cells our vessels aren't made of some other material it's also made up of cells just like our whole body so remember that so we can see here the most inner layer we can see here these are like red blood cells and there's a whole bunch of other things that I didn't put in here but just remember this this's inside here is going to be our blood now the you can see the most inner layer here we can give a name this is our endothelium okay it's a very thin it's one one layer thick okay and its job we'll talk about in the next slide just want to give you the names of these structures then we got muscle look at this layer underneath the Endo endothelium you can see it's a lot of layers it can be very thick in arteries it's very thick it can be many many layers thick depending on on what kind of artery look at like for example um a big artery a large artery may be very very thick and an arterial maybe a bit thinner slightly thinner so depending on how big are arteries uh will depend on how thick the uh muscle layer is but no in arteries compared to veins it's very very thick um what else we got here so inside here this empties the space the open space here that contains blood we call that the Lumen so the open space here in the middle the uh the hollow part of the vein of the artery is called the Lumen and in an artery it is relatively narrow because the muscle layer is so thick because it's so thick the Lumen has little has quite little space so the Lumen is relatively narrow and we're going to talk about why that's useful later and then lastly we got this most outer layer I don't want you to worry too much about it I'm just going to put it here be aware of it it's called The adventia and it's just a little layer um made up of relatively strong material we can call it collagen but don't worry about it too much okay it's not that important for you guys to worry about I want you to really worry about the muscle layer being very very thick in the arteries that's a very key thing to understand and also know that this muscle layer um and other parts of this of this artery contains a bunch of elastic tissue very stretchy tissue and we're going to talk about that as well and it's very thick in arteries so I want you the key thing I want you to take away from arteries is that they have a very thick muscular layer uh very narrow Lumen and also a lot of elastic layers um distributed inside the vessel uh um in the vessel wall okay everywhere now let's go to veins I mean capillaries so the arteries are now um the blood is now sent through the arteries to the capillaries where we know all the all the magic can happen all the nutrients can leave and all the waste can enter here okay that that's what makes these capillaries so special so a bunch of capillaries like this together a group of capillaries like this is called the capillary bed who knows why it's called a bed just un just memorize that don't know why who made that up but it's just called capillary bet this area here and here we zoomed into one capillary so it's clear to see you can see it's capillary is so small it's made up of one cell layer compared to the archery which has so many cells so many layers way thicker capillary is really really small and there's barely enough space for a single cell a white red blood cell okay so it's basically made of one layer endothelium okay okay now we know the blood is going to drain out of the capillary bed this might be a bit of waste blood right nutrients have been sucked out but all the cells around here and now we have the veins so what's different about the veins compared to the arteries so first of all they're purpose right they're coming back towards the heart now let's label some stuff let's start off here with the inner layer the inner layer here is the same it's an endothelium we're going to talk about the function later also one layer thick then we've got muscle but I want you to notice now the muscle layer compared to the artery is much thinner okay it's much thinner it's not as thick at all and therefore the Lumen the empty space inside is bigger than the artery the arter is Lumen it does not that clear on this image that I give you here but the lumen in artery is relatively small because the wall is so thick and a vein is the opposite because the wall or the muscle layers are relatively thin the Lumen is quiet big okay it's quite big um also remember because the muscle layer is thinner there is also less elastic layers remember the muscles the elastic layers are distributed here inside the muscle and other places of the artery wall there is less of those elastic layers in the veins and less muscle okay so it's thinner and lastly we also got this last outer layer again the adventia just for strength don't worry about it too much I want you to just understand from veins that they are thinner the walls are thinner and then last important thing I want you to understand from veins is that they have these little structures here which we're going to talk more about in this video they are called valves V for valves the veins have valves so remember that the veins have valves not the arteries or the capillaries just the veins they love to ask this in multiple choice okay so here now we outlined the all these structures that you need to know how to label um about archeries capillaries and veins all the three kinds of vessels in our body the transport vessels now we're going to look at the function okay the function is going to have quite a few things but I hope it makes sense I hope it's clear enough let's get into it so let's first start with Our arteries okay arteries again purpose of arteries I already said this but I'm going to show it here for you guys cuz I know you guys like to have the words written out as well other than me just saying it for you guys so arteries they take blood to the capillary bed away from the heart okay I can show you again from the heart it's pumped away that's why it's called arteries towards the capillary bed okay where the cells are that need it okay what next so arteries I just said are very thick thicker compared to veins why is that think about it the artery is receiving blood from the heart the heart is a pumping machine it's going to generate so much pressure by forcing the blood out of the heart into these arteries it's going to be a lot of stress on the on the artery there's going to be so much um blood in here at once causing pressure so if these arteries are very thin and weak like veins they might burst so it's very important for the arteries to be thicker so that they can withstand more pressure as the heart is pumping all that blood into the artery okay that's important to understand that's one reason why the arteries are so thick in terms of mus muscle and elastic layers okay okay endothelium the most inner layer I just mentioned here the endothelium what is its purpose really all you need to know is that it's like a slippery little layer of cells so it reduces friction when the heart pumps that blood into the artery that little layer is nice and slippery allowing the the the blood to just flow right by instead of being really instead of being stopped by all the friction okay muscle remember for arteries it is very thick take that away it's very thick okay why does that matter first of all um for contraction so you know me and you we got muscle on our biceps we got biceps we got triceps we got glutes we got all these muscles that we can control with our brain when I want to punch someone or I want to pick something up I can just think it and it will happen right so unlike those skeletal muscles that we have on our biceps and triceps there there is also muscle in our little vessels these little muscles here but the thing is it is not controlled by you it's not voluntarily controlled by you it is controlled by your autonomic nervous system this system is out of your control so these can contract but you have no idea when to contract them you can't cause them to contract your body will be in charge of that okay so it's controlled by autonomic nervous system so it can contract and we'll see why that's useful like why on Earth would we want the arteries to contract contct why we're going to see that now on the next diagram I want to show you so um other than other than being able to contract because it's so thick it provides strength and that's very important why because remember the arteries have to withstand a lot of pressure as the heart um forces a lot of blood into there so when it can because it's very thick it can withstand a lot of that pressure okay now let's look at a little diagram that's going to help us uh wait before we do that I want to reveal this last one so remember how I said that we also have a lot of elastic layers distributed in our wall in between our muscles or other places so they're very important because think about it elastic means it can stretch okay and when things can stretch it means they can return back to normal like a rubber band when you pull a rubber band it stretchy but when you let go it's going to recoil back to its original shape so because our artery has a lot of these elastic layers it can also stretch and recoil why is that important so these two the muscle and the elastic layers have one kind of joint function let me show you so imagine imagine this imagine your arteries were very stiff they had no elasticity so this is not what it's actually like but if you understand this scenario then you'll understand why it's important that there's elasticity so imagine there was no elasticity it was stiff and your hard pump blood because this walls are Rock Solid the blood will be really really fast and flowing really really hard here and then slow down and slow down until it's not flowing anymore right you can think about that imagine you have um you blow water into a pipe or you blow air into the pipe initially the pressure is so high and it's moving very fast and then as it go goes further and further it stops flowing until it stops flowing at all right this is what's going to happen if you have no elasticity in your walls when it's rigid you're not going to be able to have continuous blood flow all the time and that means um this is not what it's really like so what's it really like because our arteries actually have a lot of these elastic layers when the heart pumps and forces a lot of blood in our walls our archery walls can expand a bit stretch a bit accompanying more blood and because they can stretch a bit what does that mean like a rubber band they can recoil they can recoil so what's going to happen is initially they will stretch out and then they will recoil along with the contraction of your muscles because you also have muscles there so not only does the elastic layers recoil back to normal but the muscles out of not out of our control remember the autonomic nervous system controls them they will contract along with the recoil of the of the elastic n they will recoil back and kind of squeeze that blood further along so because they recoil back now they force all this blood in here to move along okay so that's very important so this elasticity helps the blood to continuously flow along unlike how it would be if it was stiff so the blood comes in high pressure The Recoil and the contraction of the muscle squeezes the blood all along and this continues to happen all along the artery until the end so this way the blood flow is continuing it's not like um a lot of blood and then nothing a lot of blood and then nothing it's continuous the blood is here and then it gets squeezed all along so it reaches the end so that's very important our elastic fibers and this muscle is very important for allow allowing Continuous Flow okay all throughout the vessel okay so here we have sorry here we have the word form of that you can read that if you want to so just understand that is the role of Our arteries okay for stretch and recoil coil that's very important in contraction okay very important arteries have that otherwise it' be a hell of a story okay last one remember the Lumen is very small uh that's very important because if it's a very small Lumen that means there's a lot of pressure when there's a lot of pressure like that inside the Lumen then the blood will move very fast through it right because it's because the blood behind it will press on it and allow it to move forward so when we have a very small Lumen the blood will move very fast because there's no space but no space to go except forward okay if the Lum is very big the blood has a lot of space to go to okay but it's very small the blood has nowhere to go except forward so the flow is maintained so a small Lumen is very important because it maintains the flow so that the blood can go all the way from our heart down to the smallest arterials okay otherwise it would be very difficult for the blood to continue all the way along till the end if the Lumen was very big okay and last one adventia don't worry about it just for strength so let's go to capillaries I like capillaries most simple to understand so our capillaries like I said said is the site of nutrient exchange where all the good things leave the capillary and go to the cells and all the bad things go from the cells into the capillaries to be taken away by the veins so what's special about them is that they are very very thin like I showed you right they're like one cell thick one cell thick that means that the that the nutrients and things can very easily wiggle waggle through the cells and reach the outside area where all the cells are okay so they're very thin and permeable permeable me just means things can easily pass through it okay um there are special places in our body like our kidney and our intestines where the capillaries are even extra permeable like more permeable than normal because the intestines you want all the nutrients to go into the capillaries and the kidney want all the waste to be filtered out so these capillaries are even more permeable so that all these nutrients can come in in the intestine and the kidney can filter out all the weights very easily so these are places where the capillaries are what they call fenestrated so even even more permeable it just means they have a lot of little holes in them um compared to normal capillaries that are not that permeable okay remember capillaries are everywhere so when you look at um let's go back here to all the branching the capillaries have so many branches so many branches compared to a venel look a venu has like some branches but capillaries have a really huge network of branches this is done so that they can reach all the cells in our body right because we have so many cells and the capillaries need to supply all of them so know that our capillaries what's unique about them is that they are very highly branched compared to the arteries and the veins okay endothelium same thing reduceed fraction Lumen very small um is very very small as you saw like literally one cell can fit in there and that's very important because because this allows um the capillary bed to have time for nutrient exchange to happen because the flow remember the flow is really fast in arteries and then over time when it reach the capillary bed the Lumin is so small and there's almost no space that the flow slows down quite a bit quite a lot it moves very slow at this point in the capillaries but this is important because this gives us time for the nutrients to leave and waste to enter if the blood just flowed by like zoom zoom there'd be no time for nutrients to enter and waste to leave I mean nutrients to exit into the cells and waste to enter the capillaries there'd be no time for that so it's very important that the Lumen is very very small and that the flow is very very slow it gives time for things to happen otherwise there' be no time for that okay so here we have the diagram blood comes in fresh and oxygenated comes in and see because it's so thin nutrients can leave to the cells and waste can enter and waste can be taken away so because the flow is very very slow here that gives time for this to be able to happen if the flow was very fast like in the arteries there'd be no time for that you got to give time for the job to be done so let's now go to the veins so veins take blood away from the capillary bed to towards the heart so the opposite of the arteries they are thinner remember because they are so far away from the heart once you understand blood has to be pumped from the heart and be and then the all the way through the arteries and then the capillaries so the by the time they reach the veins remember the blood flow is really really slow in the capillaries so so that nutrient exchange can happen so the blood entering the veins are moving really really slow so because they're moving really really slow there's no point in the vein having a very very thick wall it doesn't have to withstand any pressure there's no need for that we'd rather have the vein have a very big Lumen so that a lot of blood can be carried back towards the heart so the veins they are very thin okay because they don't need to withstand all this high pressure okay the endothelium again reduce friction so the muscle let me show you both these at the same time the muscle is very very thin because it doesn't need to contract so much um compared to the arteries and they don't need to be as thick and strong because of the low pressure um they also have less elastic layers so less stretch and less recoil compared to the elast compared to the archery elastic layers okay that just makes sense because there's no um uh rush for the blood to go back okay Lumen opposite from the arteries is very large um unlike the arteries that's very small now the last unique thing remember is valves so veins have valves I'm going to show you a diagram now here so valves are little things here inside the veins okay they are little oneway doors oneway doors meaning blood can only pass one way through them okay the valve can only open one day one way so for example if we have the vein here and the blood is traveling upwards blood can travel through it because this vein this valve opens this way but if blood wants to come downwards the valve shut closed think about it imagine the blood's flowing down the blood is going to force these valves to shut close so blood cannot flow backwards so the veins uh the valves in the veins are very important to ensure oneway flow why is that important remember I just told you that the blood flow in veins is very slow CU think about it it's coming from the capillaries that the blood flow is Flowing like one cell at a time so the veins blood flow is so slow that you need the valves otherwise the blood will just keep dropping back to the bottom okay so because the blood flow is so slow the blood isn't being forced upwards the blood can easily fall backwards and back into the capillary bed if there's no veins if there's no valves so the valves are very important to ensure that the blood goes back to the heart eventually and doesn't keep falling back due to gravity because the blood flow is so slow so this brings us to another point of muscles one very key thing for our muscles you know our muscles are very useful because it can make us move and do things running jumping whatever but another interesting thing our muscles are useful for is here if you have a vein here that has Valves and your muscles are relaxed the veins are not being compressed right and remember the the veins have very thin walls so they're very easily compressed compared uh compared to arteries arteries are very thick so to compress them it's very difficult it's they're too strong but veins can be very easily compressed so when your muscles are relaxed around the vein um the the what's going to happen is the blood will just stay the way it is okay obviously the valves are preventing blood from flowing downwards back down right that's very important because we don't want the blood to go down we want to go back to the heart but when your muscles contract they squeeze the these veins and remember the veins are very weak very thin so they're very easily compressible but when you compress them now you're going to try and force some blood up and some blood down but thankfully because of the valves the as soon as the blood tries to move down the valves prevent them and they can't move down so the blood is ultimately forced to go up so by moving your muscles and Contracting your muscles you actually help your veins to move the blood back up to your brain back up to I mean back up to your heart so that's very important that's why exercise is very important when you sit on a plane for a long time and you're you're not doing any movement your blood kind of stagnates in your legs and causes swelling and all that but when you move around in the plane you contract and help your veins to move the blood back up to your heart and you reduce the swelling so that's very important so in general in general physical activity is very important for this reason you can't just sit down all day okay because you're going to get a lot of swelling and have a when when blood when blood ends up being very still in one place for a long time they can very easily form blood clots so you can get strokes and heart attacks and all that so exercise to move this Blood constantly around and back up prevents them from stagnating and causing like strokes and heart attacks and blood clots from forming so that's very important okay that's it and the last one adventia which is for strength so that's very important we covered the hardest stuff just now in this video already okay so we got these three vessels we know their structure we know their function make sure you know their differences their similarities very important uh here I want to show you a real picture so this is like if we take a real real slice from our body and we look we can see here the three um vessels the big thick one look at the thick wall that's an artery very thick muscular layer the endothelium the adventia elastic layers in in there that helps it to stretch a little bit you can see it's very thick and inside there there's blood cells and all that sort of stuff this is the Lumen that has some blood cells in it so you can see this is the artery because it's very thick this is the vein because look how thin the wall is so so thin with a huge lumen so I think this image is really great because it really shows you the real scenario in our body thick walls for the arteries Lumen um the vein um very um very big Lumen very weak you can see how fragile and weak it is it's very thin the wall okay um and the Carill really really small one cell layer thick you can barely even see it with the Lumin inside that's very tiny so this image is really useful to see the real scenario and you can see all the tissue around it um just around around in our body okay here's a little summary these these are just very important these are not all the things that you that um this you shouldn't only remember this table like I said on here there's a lot of little details you should know if you want to get top grade um these are these here are some of the most key things so if you have no time remember these but if you want a really good grade obviously focus on all the things that I mentioned but here's a nice summary of some differences between the arteries the veins capillaries okay next we're going to the second last part measuring pulse rate this is this is pretty straightforward so let's go quickly on this so your pulse rate is the number of times your heart beats per minute so athletes for example will have a very low pulse rate they don't need to uh their heart doesn't need to beat that much because they're so fit they don't need that much blood and nutrients and oxygen because they're so fit they can um kind of do a lot with so little okay so two places where you can measure your pulse rate is radial archery and your car artery so your radial artery is basically if you you can feel this artery on the thumb thumb side of the wrist with the Palm facing up 2 cm from the base of the thumb so just go feel your wrist near the thumb side of your wrist two cm from the base of your thumb if you feel there you can move around a little bit if you can't feel it so not everyone's is exactly on the same place and then after a while you might feel it Doof Doof Doof if it's beating very fast uh you're either very nervous and seeing some lady in front of you or uh you're just very unfit okay here's a character arter this one is they like to use this in the movies because it's very big and easy to find um it's on your neck on the side of your neck it's very big so it pumps quite hard compared to rad radial artery you can just feel around for that next to your track here now how do we measure pulse rate very important to understand I'm going to read this here because I wrote it specifically so it's clearly to understand so first you feel for your pulse once the pulse is felt then start a timer for 60 seconds during these 60 seconds count the number of pulses so if you count 80 beats in that in that 60 seconds your heart rate trate is 80 beats per minute okay but sometimes you don't have the time to wait a whole minute so what you can do is you can do it for 30 seconds and then multiply your pulse number by two so let's say you feel for 30 seconds and you counted 40 beats okay so now you can just double that to find out how much it would be in one minute that that' be 80 beats okay so that's how you measure your pulse rate very important it's a very good way of figuring out if someone is dead because there be no pulse rate if there's no pulse that means uh no blood is going to their brain to their organs and so their cells are going to die soon so you need to save them CPR okay last part here coronary arteries so you need to know about a kind of specific artery that is actually on our heart this artery is so your heart will pump the blood into this little artery away from the heart but onto the heart isn't that interesting so this is a because you might wonder okay the heart is pumping blood to the whole body so the whole body can get fresh nutrients and oxygen to survive but how does the heart survive that's very interesting these coronary arteries are little arteries that are supplying the heart itself so the heart not only does it pump blood to the whole body it also pumps blood to Itself by the coronary archeries these little arteries so these are arteries that Supply the blood to the cardiac muscle because the heart is just a big big muscle that is not controlled by yourself right it's you don't you don't decide how many times you uh how often you beat your heart right it's controlled by your autonomic nervous system it's not controlled by you so this blood will go to the heart itself and keep it healthy and all that now normally these coronary arteries will be nice and empty I mean not nice and empty but nice and round just have blood inside them but sometimes you can have a problem where you have an occluded artery so a little plaque something some things called plaque will build up plaque is like little fat and um fat fat things and other um fibrin and things like that that build up because of bad habits like smoking and eating a lot of fat things a lot of lot of things contribute we'll look at it now but when these are olude when these arteries get so uded that blood can barely flow past them then that's going to lead to your heart dying right CU imagine imagine this little area gets occluded now blood can cuz here blood can flow very easily nice and freely supplying the heart but it gets if it gets occluded like this there's a very limited space for blood to flow past so this area is not receiving enough oxygen and it's going to start dying so we call this coronary heart disease or in simple terms a heart attack when you have a heart attack it just means your heart is not receiving enough blood because there's some occlusion or something going on preventing the blood from reaching the heart and that area is going to die off and when that area dies off that's a problem because now your heart part of your heart is dead and your heart is supposed to pump blood the rest of your body so if your heart is not working then the rest of your body is also going to be missing blood now and start dying so you might pass out or whatever you might die all right if you don't solve the problem quick enough so that's what you need to know so here are some factors that can be correlated with a coronary heart disease will correlated with this problem sometimes sex can sex can influence it like as in whether you're male or female age can influence it like obviously older people are more likely to have coronary heart disease because of their bad habits since since since when they're young um family history maybe it's in your genetics maybe your diet will affect it if you don't eat healthy foods maybe if you have diabetes hypertension so what or smoking is very important so what I want to say is that there's not one single thing that causes coronary heart disease or this ATT buildup inside your coronary arteries it is a combination of many things so we call it a multifactorial disease so you have to take care of yourself in terms of everything obviously you cannot control your sex your age your family history but you can control the other things so make sure you control what is possible to control the rest is not up to you right okay so that's it we covered a lot now we're going to do some questions um and then we'll move on to the uh plant part okay the plant part which is much shorter so question one here what helps to keep blood flowing on onwards away from the heart in an artery away from the heart it's going to be arteries we know arteries so what about arteries allows blood to continue flowing away right we learned that we learned that arteries do not have V so it's not going to be a they do have a lot of elastic fibers and this these elastic fibers remember if we come back to it here these elastic fibers is what allows the blood to continuously move all the way down the the elastic fibers and the muscles Contracting okay uh contraction of skeletal muscles no they don't help blood move away but they do help blood return to the heart um by compressing the the veins right we learned that here the veins can be compressed the veins can be compressed by skeletal muscles helping blood return to the heart but it's not like that for the arteries okay having a wide Lumen the artery does not have a wide Lumen it has a narrow Lumen and narrow Lumen helps to help blood flow away from the heart right because a narrow Lumen makes the blood flow faster because there there's no space to go except forward okay so the answer here is going to be B what is the role of coronary arteries we just learned this one to supply information about blood temperature to hypothalamus no it does not do that that would be some kind of nerve um to supply the heart muscle with oxygen and nutrients yes it's going to be that one to carry blood away from the heart um no it carries blood towards the heart itself so that the heart can be supplied to monitor blood pH nope definitely B which blood vessels have thick muscular walls that can resist pressure and assist in pumping blood arteries right they have very thick so they can resist the high pressure from the blood coming from the heart and they can assist in pumping blood because the the elastic layers can recoil and the muscle the smooth muscles in the vessel can contract to help squeeze along along the vessel all the way down so the answer is going to be arteries so Atria is a is a chamber of the heart which you learn about later veins do not help move how do not help pumping blood and they can't resist high pressure because they're very thin and ventricles is another chamber of the heart which you'll learn about so the answer is going to be a oops oh something's happening okay let me just fix that for you somehow I didn't prepare that hey okay last one what is a similarity between archeries and capillaries um the answer here is going to be neither has valves remember the only one that has valves is your veins okay so that's very important to understand very key difference so here lastly I want to show you a big question um this is from the old syllabus because obviously there has been no new exam on the new syllabus so do this question with regards to all the information you learned in this video develop yourself a nice answer and make sure you can answer this kind of question on the test this is one very key question they can ask because it's largely what we learned in this chapter here is the mark scheme from the previous syllabus there's like 90% overlap so it is very very similar so you can use this Mark scheme to guide you but no it's from the old syllabus so it's not exactly the same so you might have to modify your answer a little bit so just like animals plants also have their own ways of transporting things from where to where they need to go they have their own little vessels their own little pipes that make sure everything goes where it needs to go but it's a little bit from from from animals right and let me show you I think the best way to explain this we're going to tell a story of this little guy here our water which is in the root all the way from the root up to the leaf okay and then as we go along we'll explain all the little structures and it should make sense and everything you need to know will be there so let's start off here in the root and bear in mind I'm talking specifically about plants called diodon plants we can split up all the plants into two categories diodon and mono caladon we're only focusing on the dialon plants okay cuz that's what you need to know for the IB so don't get confused when you see this word just know you are learning about dadon plants so now we're in the root here and we know the the the the roots here are anchored into the soil right why because the roots is the thing that's going to absorb minerals and water into the root right so how does the root look like our root has looks vaguely like this and let's reveal some structures we got the outer layer here the epidermis okay and then we've got the cortex which is this whole thick green part and then in the center I mean the little layer here surrounding the center is going to be our endodermis and then in the endodermis we got two key vessels so this is where the real vessels are the pipes like in the humans the arteries and the veins these are the vessels in the plants okay and we're going to call them xylm and flm I like to remember it as in the xylm here is in the center and it looks like an x a little bit right the xylm okay and then the outer part here we've got the FL now the flm I remember it as P for periphery so the flm is always on the outside and you'll see it's the same when we look at the stem okay so now the xylm the function of the xylm and don't worry all these words I'm saying I have a little table later where I have all the structures and a sentence describing them so don't worry if you can't catch everything now the xylm is the structure that's actually responsible for moving the water okay it's the pipe that water is transported in so if we have a little water here that comes into root in actuality it's entering the xylem now the xylem will move that water up up to the stem and then up to the leaf okay so know that the xylm is where the water and the minerals are being transported the flm is another pipe and it's transporting carbohydrates like sucrose kind of like sucrose that that plants need for energy and things like that so it is transporting something slightly different from the xylem okay now the epidermis this layer here on the outside what's unique about it it is the layer where water has to pass so sometimes the epidermis can grow little hairs like little hands that basically help absorb the water okay so the root can have a little bunch of little hairs on it that help absorbing water even better okay so like a bunch of little hands grabbing the water and pulling it in okay the cortex is mainly for structure it doesn't have like a spe specific key function it's not very specialized it can also store certain things certain nutrients but it doesn't have any huge role okay so again the combination between the xylm and the flum we call that our vascular bundle so here is a realistic image that you need to be able to recognize again you can compare and see it's very very similar our cortex our epidermis endodermis the xylm and the FL make sure you can recognize both because you may need to be able to draw a cartoony version of of a of a root structure a cross-section like this or even they may give you a one and you need to label it so be make sure you can do you can recognize this very well so now the water comes and it's been moving up in the stem um to the top so what's interesting here how does water just move up CU in in the animals we know we have a heart and the heart is the thing that's going to pump pump the the blood everywhere through our vessels but uh does a plant have a heart no it has no heart so what is causing the water to move upwards Against Gravity we call that process capillary action and we're going to look at it later in detail okay so now we have the water coming up to the stem how does the stem look like so we cut the stem let's take a look at it you can see it's a bit more complicated let reveal things so there's some structures here that you need to know let me show you uh first of all here the brown part that's the xylm and then the blue blue one here is our flm see again the xylm is more towards the center that's how I like to to remember it okay and the P for the FL is near the periphery it's more near the outside and again the combination of these two are FL and our xylm we call the vascular bundle now what's similar we also got the epidermis just like we did in the root um then we got the center part the thick center part called the pith I cross it out here because you don't need to know it I'm just labeling it here because when you see a real image that structure will be there and I don't want you to be like what's that do I need to know that okay just labeling everything for you guys and then what's this black thing here cuz we got the xylm the flm and this black thing uh this black thing is called the pericycle and you don't need to know it but you're going to see it on the realistic image so I don't want you to get lost when you see that okay you don't need to know what it does though it's there um next to the flm then we got this cortex here so that's similar to this the the root here that also has a cortex and then we have this white line in between the xylm and the Flom you also don't need to know what that is it's called the vascular cambium and it's basically a little area that stimulates the xylm and the flum to grow properly so know the things that are not crossed out here okay know the things are not crossed out and the xylm has the same function in the stem that it has in the root carrying water up water and minerals upwards from the root and the FL has the same function as in the root carrying sucrose and things like that in the plants okay for energy so here let's look at a realistic image so see they have this little black structure here so if you saw that and you didn't know what it was you might be like wait is that the flum now because it's the you you might get confused so don't get confused it will look like this on the real image so we can compare Center here the pith we got the epidermis we got the pericycle don't need to know it though the FL and then the xylm okay so make sure and then the cortex so make sure you can recognize again the same way as the root make sure you can recognize it label a diagram if you're given one or draw a very vague diagram now because it's the IB I saw in the the book they completely ignore the pericycle so sometimes you may be given an image where there is no pericycle it was deleted so in that case when you only see when you see a picture of two regions like this one here one here with no third region just know that the most outer part is then the flum and that's the xylm that means they ignored the pericycle so just that's a heads up for you guys okay so now our water is moving up we got no know what the root looks like we no know what the stem looks like so it moves now up to the leaf let's take a look at the leaf structure oh yeah first maybe many of you want to know okay how the heck does the structure change from the root to the stem in a split second like that how does that happen so it's kind of interesting you don't need to know it but I want to show you it just as cool to look at so in the root the vascular bundle in the center is like this and as the stem starts forming branches start forming from this vascular bundle to the outside of the pipe to the outside of the stem that's why it ends up looking like this having a bunch of vascular bundles distributed near the periphery okay so again don't need to know it just be aware of this concept I think it's pretty interesting okay it may help you remember the idea a bit better of the root in the stem so here is the table I promise you guys all the structures and their functions remember it's for dialon plants not monocon plants and then here we got the stem so remember xylm transporting water and minerals up from the roots but it can also serve as mechanical support in the stem so it can have two functions bear that in mind not only moves water and minerals but it happens to be pretty sturdy and strong and that helps the stem prevents it from collapsing or falling over okay awesome so now finally like I said we're at the leaf okay the leaf structure was covered in another chapter called gas exchange um where we talked about gas exchange in plants so I'm not going to go into detail here I'm just going to show you the structure you don't need to be able to label this kind of structure for this specific specific chapter you do need to label it for another chapter called gas exchange but right now it's going to be useful in explaining transport and plants so we're still going to use it but don't this is not the emphasis of this chapter so here comes the water it's being transported in what the xylm so here is our xylm here you can see here's our vascular bundle of the xylm and the flm the water comes out it will leave into these empty spaces in the layer called the spongy mesop so understand this image the top here is the top of the the leaf and the bottom here is the bottom of the leaf so the water will go in go to certain cells that need it because it's got minerals and water and all the cells need that and eventually it can be sweated out yeah just like in humans right in humans we get rid of water through Sweat Right we call that sweating but in Plants we call sweating transpiration so when plants get rid of get rid of water out of the leaf we call that transpiration which is the equivalent to sweating in humans so where does it exactly get sweat out of here these little holes called stom so there are certain in the epidermis at the bottom of the leaf we got um little cells here called guard cells and they can control how big this hole is if they decide to if they want this hole smaller they can make themselves bigger and therefore make the hole smaller if they want the hole bigger they can make themselves smaller to make the hole bigger we call this hole the stom so this is where sweating or evaporation of water can happen from it can leave right out there into the environment okay so I want to give you another view of that here so if we look now not from the side because this image here is a cross-section it's a side view of the plant right we're looking at from the side I want to give you now a bottom view so you look at the leaf from the bottom we can see a bunch of these little holes these stoas everywhere so let me show you one area where the hole exists so here is okay great here so you can see here if we look at the bottom the sto this little hole here and the surrounding two cells these cells the guard cells can move and change their shape to increase or decrease the size of the stoma and therefore influence the rate of sweating or transpiration in Plants okay and then all the cells surrounding that are not um um that are not guard cells here are called epidermal cells okay just these here okay so great so make sure you can recognize both the side view and the bottom view it's very important so ultimately we had this little water from the root move up by capillary action to the stem and then to the leaf and then leave the leaf by um through the stom by transpiration okay that's awesome so now we know how um water and and things are moved all around the plantet in these little vessels we also we know that for plants and we also know that for animals you can see how they are very different so now we real quick got to look at the xylm structure okay xylem structure so the xylem you um before it's formed it's actually a bunch of living cells stacked on top of each other like this to form the xylem these cells end up dying and merging together so let me show you they die and now they are the the membranes aren't there anymore separating them so now they're one long pipe you see so let's look at some features so the xylm when it's formed it's just dead cells dead cells not living and they have these little holes in them which allow the water and things to move in and out um very easily otherwise the water will be confed to the xylm and can't go to the cells so the pits are very useful to allow water to move out of the xylm not only that the walls here have a material in them called lignan which helps keep them strong okay need to know that so that's why the xylm can also serve a structural role to keep the stem very strong now notice the here the walls are absent to make a pipel like thing right very important and water will move upwards from the roots to the top of the plant so one key big brain tip Quattro for this video which means four is xylm is the dead left over walls of cell while the flm which is the other kind of pipe which carries sucrose is living okay that's one key difference between the xylm and the flum so know the structure of the xylm and these key points about the ZM now remember that the the plant does not have a heart so the process by which water moves from the root up into the stem up to the top of the plant we call that capillary action this is a concept that is explained in a1.1 so I'm not going to give detail on it essentially water is absorbed um into this the the stem and the root due to that creates negative pressure the negative pressure causes the water to move up due to its properties of cohesion and adhesion um and so on okay so the process is a little complex if you want to understand it go watch a 1.1 okay but for now just know the process is called capillary action okay so finally get some questions what is transported in xylm tissue we know here the contract by yourself the answer is going to be C water from the roots to the leaves what where does translocation of sugars such as sucrose occur in a plant stem we know that's the flow so that's going to be here the outer part here the B because that one in here C would be the xylm which structure is shown in the following image I told you it's a diodon stem right so there's two monocot and dcot remember this is dcot that we're learning about last one here the diagram below shows the cross-section of a stem what is the structure labeled Y and one of its functions so we know that is the xylm the outer one here is the flum so the xylm you can know it does two things transports water and minerals up or mechanical support so the answer here will be B so I hope that video was useful I know there's a bunch of stuff it's a little bit complicated but I hope it made sense and I'll see you in the next one one