Respiratory | Respiration at High Altitudes

iron engines in this video we're going to talk about respiration at high altitudes why is such a big deal because you know when you're at high altitudes for example if you decide to go and hike Mount McKinley or Mount Everest there can be some dangerous things that can happen if you go to high altitudes very very quickly and very fast it can be very deadly so we're going to talk about is how our respiration changes during the actual ascent during the high altitudes ok let's go ahead and start there so first thing that we need to understand about being at high altitudes is what the actual atmospheric pressure you know when you talk about the atmospheric pressure generally atmospheric pressure where barometric pressure is approximately 760 millimeters of mercury and out of that 760 millimeters of mercury it's a mixture of many different gases like nitrogen and water vapor and oxygen co2 well what we're talking about here is oxygen because of high altitudes the availability of oxygen decreases why so as you go higher the percentage of oxygen out of this pressure decreases so normally normally the partial pressure of oxygen is 21% of this so if you take 21% of 760 millimeters of mercury it'll give you approximately 160 millimeters of mercury about right now what's the problem how is this such a big deal right when you ascend high altitudes the availability of oxygen decreases so the percentage of oxygen within the atmosphere decreases so then the partial pressure of oxygen within the atmosphere decreases so now let's look if it's less than 21% less than 21% this new partial pressure of oxygen is going to be less than 160 milliliters of mercury okay now you might say okay why is that such a big deal we're going to see here in just a second let's say here I have the long right and then the long it's made up of many many many different alveoli okay we're going to treat this whole space in here as an the old line okay we're going to show you this whole space here so now let's say that the partial pressure of oxygen normally within the lungs normally at normal sea level is approximately about a hundred and ford we're going to keep it at yeah average about one hundred millimeters of mercury so normally the partial pressure of oxygen within the alveoli is approximately a hundred we'll write it down one hundred and four millimeters of mercury that's approximately right but that's whenever it's at 760 and the percent of oxygen is 21% if the percent of oxygen decreases and it goes below 21% now there's going to be disastrous effects now some of you might be wondering okay I don't I don't get I thought exactly remember in the videos you said that air moves from areas of high pressure to low pressure until equilibrium is reached well if that's 160 out in the atmosphere and this is 104 here in the alveoli that doesn't make any sense shouldn't it be 106 yeah it should but guess what happens as oxygen is coming down into the actual lungs it mixes with some water vapor and as it mixes with some of the water vapor some of the oxygen actually gets you lost in that process so the amount of oxygen it's actually coming down is only 104 so you actually whenever it combines with some of the water vapor as it's moving down you actually lose some of that oxygen and then it becomes 104 millimeters mercury so if it actually drops if the partial pressure of oxygen is in the atmosphere when you go to high altitudes drops below than 160 what's going to happen to the partial pressure in the alveoli it's going to drop a low 104 significantly so for example let's say I drop down to like 130 okay so the partial pressure of oxygen in the atmosphere drop down to 130 then the partial pressure of oxygen within the avital is going to drop down significantly let's suppose though for this actual video we're going to suppose that the partial pressure of oxygen is in the atmosphere it's so low that it causes the partial pressure in the alveoli to drop down to approximately 60 millimeters of mercury okay so we're going to assume that the partial pressure of oxygen with an altitude and the atmospheres whenever you're going high altitudes is so low so less than 160 that whenever it moves into the alveoli it actually becomes about 60 millimeters of mercury suppose that why is that a problem okay so remember the structures that we had with inside of the actual specifically the major medulla and the pons you guys remember that real quickly what do we have this was the vrg right eventual respiratory group consisting of complex of neurons clusters and neurons this was the DRG this was your central chemo receptors this was your apt newest extensor and this was the pneumo toxic Center both of these were making up your Ponte and respiratory group right so both of these pneumo toxic center in the optimistic center collectively are making of your pontine respiratory group so pontine respiratory group all right cool well now if you guys remember the V R D and the G R DRG had very specific inspire toward neurons right those inspired Tory neurons were doing what well they could send down let's actually do this in an orange they would send down these actual fibers right they were sending down these actual descending axons and these descending axons were coming out and stimulating specific actual what cell bodies here right the somatic motor neurons within the ventral gray horn and what were they doing they were coming out and collectively forming the actual neuron that were going to supply the external intercostals and that we're also going to supply the what diaphragm and again if it was the diaphragm it was actually going to be via the phrenic nerve and if it was going to be through the external external intercostals it would be the intercostal nerves and if there was the intercostal nerves that was at t1 and T 11 friended nervously three to c5 right okay well this is the normal way if you guys remember from the video when we talked about the control and the regulation of respiration we talked about what happens whenever the partial pressure of oxygen is really low all right so now let's take this guy over here and let's see what's going to happen because this should make sense now okay partial pressure of oxygen within the alveoli we're going to treat this as the alveoli the partial pressure of oxygen within the alveoli now we're at high altitudes are so low that it drops to 60 millimeters of mercury all right sweet deal but then let's say as the blood is coming through what is this here's your right right side of the heart right this is your right atrium this is your right ventricle this is the pulmonary trunk pulmonary arteries we'll put P a pulmonary arteries and then coming out over here what are these going to be these over here are going to be your pulmonary veins pulmonary veins okay as the blood is flowing through the pulmonary artery what is the pressure what is the partial pressure of oxygen so the partial pressure of oxygen within the blood is approximately 40 millimeters of mercury right and if you guys remember from before air will flow from areas of high pressure to areas of low pressure until there is equilibrium reached right so what's going to happen then oxygen is going to flow from the alveoli into the blood what is that called external respiration right so where is the actual blood going to flow I'm sorry the oxygen flow the oxygen is going to flow here into the actual pulmonary capillaries and exchange this process with the oxygen so what should oxygen come out at it should lead and go into the pulmonary veins as having a partial pressure of oxygen equal to 60 millimeters of mercury okay what about co2 all right now we'll talk about co2 for a second here the partial pressure of co2 normally within this blood is going to be approximately about 45 to 46 millimeters of mercury whereas in the alveoli the partial pressure of co2 is only what let's do this in a different color let's do this in the brown also so the partial pressure of co2 is in the alveoli is about 40 millimeters of mercury so it's approximately 40 millimeters of mercury but we'll see how this stat changes during this process so again where would the air when a flow the air would want to flow from areas of high pressure to low pressure so where is this going to go it's going to go out it's going to come out here into the alveoli and it's going to move from the blood into the alveoli until the partial pressure of co2 in the blood is going to equilibria with the partial pressure of co2 within the alveoli so what should it leave as the partial pressure of co2 is it leaves should be equal to 40 millimeters of mercury so that's where it should be so the partial pressure of co2 should be equal to 40 millimeters of mercury okay why am I telling you all this because if you get this it's going to make so much sense here watch this the problem is they're having hypoxemia right what do we define as a hypoxemia it was basically whenever you have this low arterial partial pressure of oxygen what did we say whenever the partial pressure of oxygen is equal to 60 or less than 60 millimeters of mercury what chemoreceptors are getting activated the peripheral chemoreceptors so look at this the partial pressure of oxygen is so low so what is it going to do it's going to come up here it's going to go back to where it's going to go from the pulmonary veins it's going to go into the right atrium then it's going to go into the I'm sorry not right atrium it should be left atrium shame on me it should be left atrium and this should be left ventricle goes up into the aorta as it goes up into the orbit it runs up through again it can come up actually eventually to the common carotid artery so this is the common carotid artery common carotid artery this is the external carotid artery this is the internal carotid artery again internal carotid artery external carotid artery subclavian artery subclavian are you get the point right this would be the right side that'll be the left side as you go up around this point where the common carotid common carotid artery bifurcates and goes to the external kamakura external carotid artery and internal carotid artery there's these little bodies what are these little dudes up here these little smiling dudes called remember those those are your peripheral chemoreceptors and these peripheral chemoreceptors are special so again what are these structures here called they're called peripheral chemo receptors and again if they're here located within the actual carotid bifurcation point they're called the carotid bodies so these are called your carotid bodies and if they're located here at the aortic arch they're going to be called the aortic bodies and if you guys remember these are responding to a low partial pressure of oxygen whenever it's below 60 millimeters of mercury so let's assume that it actually is going below 60 millimeters of mercury it's at least 60 or below we're just going to do it's going to stimulate these guys you guys already know the mechanism it inhibits those potassium channels and the calcium comes in dopamine is released what happens to these guys then if there's low partial pressure of oxygen this low partial pressure of oxygen stimulates you guys they're going to activate their actual sensory afferent fibers of those two cranial nerves or the cranial nerves that were being activated in this process so you guys remember it was actually the if it was connected to this one if it was connected to the awarded bodies is going to be cranial nerve what 10 which is the vagus nerve if it was connected with the actual carotid bodies it was going to be cranial nerve nine which was the glossopharyngeal nerve if they're stimulating what are they going to do they're going to send signals what are they going to send signals with so down if we follow let's say that we follow the cranial nerve 10 and cranial nerve nine as they send signals over let's say that we follow the signal like this now here's the signal and again who's carrying this signal it's going to be cranial nerve 10 and this is going to be cranial nerve nine and again what was cranial nerve 10 and nine this was also pharyngeal this is the vagus they're sending centers to the respiratory centers within the medulla and within the pons what was the overall result if you guys remember well the stimulation was what let's remember what the stimulation was it was low partial pressure of oxygen and has to be at at least 60 millimeters of mercury or less it is in this case let's assume that it is in this case what is it going to do it's going to stimulate specific centers within the medulla right one of those two centers one is it's going to activate the drg the other one is going to activate the vrg specifically what action of these two guys so if we follow these guys in here what are they going to do stimulate the vrg and it's also going to stimulate the drg and it's going to activate having more frequency of action potentials so what's going to happen to the frequency of action potentials the frequency of action potentials is going to go up if the frequency of the action potentials go up what's going to happen to these actual the diaphragm muscle it's going to be stimulated heavily and frequently and then the external intercostals going to be stimulated frequently and heavily what's going to happen to these individuals they're going to hyperventilate because if you're actually having increased frequency of contraction an increased frequency of action potentials increase frequency of contractions what's going to happen to this person they're going to have increased alveolar ventilation what does that mean that means that you're going to increase the respiration rate and increase the actual depth so you're going to increase the respiration rate and the depth in other words the tidal volume in this case for the death right we can put that below the title we can try to increase that if you do that what's going to happen and if you increase your alveolar ventilation as you're going to high altitudes as you're going to high altitudes your alveolar ventilation rate is going to increase originally as you're going up to these high altitudes what's that going to try to do then it's going to try to increase the ventilation process so it's going to try to bring more air in from the atmosphere to the best of its ability so as you try to bring more air in to the best of your ability from the atmosphere it's going to attempt to increase the ventilation process what does that mean then it's going to try to increase the actual exchange of oxygen with the blood but it might not change significantly let's say that it actually goes up a little bit and it goes up to about let's say 75 or 80 whatever goes up to about 75 or 80 where's my brown marker so let's say it goes up to about 80 millimeters of mercury okay if that's the case then what's going to happen to the partial pressure of oxygen within the blood after the exchange occurs it should go up to about 80 millimeters of mercury okay that's good what happens to the stimulus now for the actual a or T bodies it goes away what happens to the stimulus for the actual carotid it goes away right and then we basically inhibit the action potentials that are going to the diaphragm the external intercostals as we increase the ventilation process to appropriate values so as we try in other words until we bring the partial pressure of oxygen below 60 millimeters of mercury to the best of our abilities above that then the hyperventilation or the increase in ventilation and depth rate is also going to slow down but there's a problem in this something happens that's not good remember I told you co2 is moving also and we know that it normally moves from 45 to 40 well guess what happens as you move to higher altitudes you know what happens within the atmosphere the concentration the partial pressure of co2 within the atmosphere it also decreases slightly so let's say now that the partial pressure of co2 within the atmosphere decreases slightly so let's say that now the partial pressure of co2 decreases slightly so let's say that a time it drops down to about it gets it's less than let's say it's actually 25 25 millimeters mercury whatever we pick a number there 25 millimeters mercury if that's the case then what's the partial pressure of co2 is in the alveolar going to be it's going to be a lot less so let's assume now let's assume that it's so low that it actually drops to about 25 millimeters mercury let's suppose okay if that's the case then what's going to happen to the movement of co2 well before it was 45 to 40 now it's 45 to 25 that's a 20 gradient difference right there right as compared to just a 5 gradient difference that means more co2 than normal is going to be being exhaled out as you try to exhale out more co2 what happens to the co2 allow partial pressure on the blood it drops it drops until these two pressures equilibria what's the partial pressure of co2 going to be now the partial pressure of co2 is going to be 25 millimeters of mercury oh my goodness this is really really bad why is this really really bad let me explain to you why it's really bad because if the partial pressure of co2 is really really low what can that do let's come over here to see what happens to the brain this is not a good thing not a good thing okay so now we said that the partial pressure of co2 is extremely low not because the atmosphere is low in sea - so now the partial pressure of co2 in the alveoli was 25 and in other words whenever there's exchange across the pulmonary capillaries the partial pressure of co2 within the arterial blood becomes 25 millimeters of mercury that means that co2 that's actually coming into the cerebrospinal fluid across is what was this call here - blood-brain barrier when the cost of the blood-brain barrier and it combines with water if these two combine in the presence of an enzyme called carbonic anhydrase in a form carbonic acid carbonic acid disassociates into what bicarbonate and it also disassociate sin 2 protons this arrow should be in this way - and then what happens with these protons these protons are normally trying to act on the central chemoreceptors well what did we say was the problem the co2 is low the carbonic acid low the h+ is low what do we say happens if it's really really low it's not stimulating the actual central chemoreceptors in other words it starts inhibiting it if this inhibits the central chemoreceptors what does it do to the drg it inhibits the drg if the drg is inhibited what does it do to the actual vrg and inhibit it what happens then - these action potentials that are going down to the phrenic nerve and to the actual external intercostals it's actually going to be decreasing in frequency so what happens to the frequency then the frequency decreases as the frequency decreases then what happens the alveolar ventilation decreases as the alveolar ventilation decreases what happens to the rate in the depth it also decreases and then what happens over here right you're going to have very very slow slow breathing and that's a problem out because the bird originally what was happening you had hypoxemia right now if you have slow slow slow breathing are you going to be able to allow for excess oxygen to keep coming in from the atmosphere no that is a bad bad bad thing and we'll talk about why because it can lead to a cute mountain sickness so again whenever this happens your drive originally was hypoxemia and then you're trying to hyperventilate to a compensate for the hypoxemia but as you try to compensate what are you doing you're breathing off a lot of co2 as you our breathing off a lot of co2 what happens you go into a situation where so much co2 is lost that it can produce a condition called respiratory alkalosis respiratory alkalosis and they say and basically that's when I have extreme your pH is really high so your pH is higher than normal and but this pH is high due to low co2 levels okay that's the actual stimulus and it's because you're breathing off a lot of co2 because the actual co2 is in the atmosphere is a little bit lower than normal so we just we change the number we said it was about 25 now okay I could have picked on any other number I just pick 25 just for that okay there's no rhyme or reason okay so again respiratory alkalosis can be produced in this situation which is extremely dangerous because now what did you do you took away the stimulus for this hyperventilation so now there's two things that are trying to be able to work here what are the two things that are trying to work how is this produced so whenever there was this low partial pressure of oxygen this was trying to increase ventilation right but then as you increase the ventilation you're trying to bring the partial pressure of oxygen back up let's assume that you bring it back up to normal okay but in that process as you increase your ventilation what did you do to the partial pressure of co2 you decrease the partial pressure of co2 very very low what does that do to the actual action on the central chemoreceptors it inhibits the central chemoreceptors if you inhibit the central chemoreceptors then what's going to happen to the ventilation you're going to decrease the ventilation so if you see what I'm saying here it's basically you're having an opposed action so there is ventilation occurring it's just not as high as you would want it to be it's very moderate instead of excessive to be able to get as much oxygen to the tissues as possible that's why it's dangerous how does our body deal with this though okay well let's say that you're you're a good hiker you know you've done this before as you're ascending you decide alright I'm going to take a couple days I'm going to stay here and wait and I'm going to let my body acclimatize okay I'm gonna try to acclimate to these actual conditions how does the body acclimate the conditions we got to go to the kidney and see so now let's see what the kidney what's what our good old kidney does for us all right in our kidney you have this is actually if you guys have watched it you know that this is the proximal convoluted tubule this is the actual loop of Henle the ascending and the descending this is the distal convoluted tubules and then this right here that we're looking at is the collecting duct collecting duct okay now there is these two types of cells present within our kidneys they're called intercalated cells and they basically are playing a role with our acid-base balance but there's one particular type there's a and B cells we're going to look at the intercalated B cells and don't get these confused with the B cells within your immune system this is the actual cells in the kidney okay now what happens with these integral A to B cells well if you guys remember we can actually bring co2 in right so let's say here's our co2 and the co2 comes in here you know that the co2 is going to combine with the water when these two combine in the presence of an enzyme called carbonic anhydrase what happens it gets converted into carbonic acid which breaks down and disassociate into protons and bicarbonate you know what our body does it says okay let's assume that right here I put a blood vessel actually let's just put it right here even though it's a vein well just it's for the purpose of understanding this okay here's two options he says okay the pH over here in the blood is really high okay hmm what can I do well let me actually not put by carbon because normally what you can do is you can bring Bart carbonate into the bloodstream right but we don't want to do that we want to get rid of the bicarbonate so look what it does it's very tricky and it pumped the actual protons out here and how you have to use ATP for this process right so in order for you do this you have to utilize ATP and other different types of ions so you're pumping the protons out into the blood but then what you're going to do with the bicarbonate you're going to excrete out the bicarbonate in the urine so as you start excreting out bicarbonate within the urine you're losing a lot of your bicarbonate and bringing protons into the blood what happens to the pH guys the pH starts going back down least normal values oh that's so friggin cool all right so that's how our body is helping to deal with this so if you stay at high if you stay at high altitude for a couple days even a week if you really want to be completely a comet eyes dry basically what's happening your kidneys your intercalated b-cells are coming to the rescue and they're putting protons back into the blood which is bringing the pH down and we'll see how that helps in just a second and then it's getting rid of the bicarbonate okay how is this fixing it because you might be like what that mean man I got you don't worry alright so look we said that there was going to be a lot more protons if there's a little bit more protons here and there's less bicarbonate so look we got rid of a lot of its bicarbonate if you decrease a lot of this bicarbonate right here it's not going to be able to bind with as many of these protons because you know that this is basically a buffer here carbonic acid can break down into two things it can break down into H+ and bicarb this is basically your buffer but according to a guy named les chatelier's he came up with this concept he says if you decrease this side right then what's going to happen you're not going to have as much of this guy over here so what's get what he going to want to do you're going to want to break down you're going to want to shift the reaction to the right so you're going to want to have more carbonic acid break down into protons and bicarb so as you do that what are you accumulating more of your accumulating more protons also you're going to have a little bit more protons accumulating within the blood too but the protons can't cross the blood-brain barrier so the main thing to remember is that your excreting bicarbonate and as you get rid of bicarbonate bicarbonate ions decreases the chatelier's principle see if I can spell this ash at leas principle is basically saying that as you decrease this side of the reaction decrease the bicarb the reaction is going to want to shift to the right as it shifts to the right you make more protons more protons are going to do what to the central chemoreceptors stimulate them if you stimulate them you're going to stimulate the drg if you stimulate the drg you stimulate the vrg if you stimulate the Vig you have more action potentials coming down if you have more action potentials coming down you're going to frequency of the actual ventilation is going to our action potentials is going to increase you're gonna have more frequent contractions if you have more frequent contractions home-like Ignis you guys should get this sorry right there's going to be an increase in ventilation rate it's going to increase in the depth and the actual in this case the tidal volume and then what's going to happen you're going to have this action here where you can go back into the type of ventilator state and do what try to bring more oxygen back into the bloodstream and exhale some more the co2 okay but you do it to a level that's accommodating it's acceptable right you're not in the situation to where you're in respiratory alkalosis or you're not having excessive hypoxemia so that's an amazing thing but unfortunately it's not enough unfortunately not enough so how else could you deal with this well the body has another way of dealing with it it's really cool all right so let's say here your kidneys come to the rescue again if you guys remember we said you guys watched the actual videos within hematology we talked about the proximal convoluted tubule and if you guys remember the proximal convoluted tubule was responsible for secreting a special hormone remember there was the hypoxia-inducible factor who was bound by that little enzyme there and we said that whenever there was low on oxygen so in this case we should be specific we should say low partial pressure of oxygen right because the partial pressure of oxygen is still going to be low it's never going to be at 100 whenever you're going to high altitudes so your body has to compensate whenever there's low oxygen you can't hydroxylate this enzyme here so this enzyme is inhibited and what happens to the hypoxia-inducible factor it comes in to activate specific genes and when it activates specific genes it produces a hormone what's that hormone if you guys remember that hormone was called e pee o erythropoietin all right what is the Rin through point I'm going to do erythropoietin is so cool because it comes over here to the bone marrow what's within our red ball marrow dance remember that we have the red bone marrow within the epiphysis of the long bones within that spongy bone right it's going to stimulate the bone marrow to start producing more red blood cells right because if you remember let's say that we draw in here what do we have we had a pluripotent stem cell that can divide into a myeloid and the lymphoid stem cell and then the myeloid stem cell can actually go to develop eventually red blood cells or it can go to make platelets and white blood cells certain white blood cells EPO if you guys remember it was stimulating the actual formation of more red blood cells if you have more red blood cells what does that mean then if I have more red blood cells I have more hemoglobin if I have more hemoglobin I can carry more oxygen so what's going to happen to the oxygen carrying capacity it's going to increase what is that called that whenever you make a lot of red blood cells poli-sci B Nia so in these individuals what are you going to see with them not all you're going to see that they have elevated erythropoietin levels they're going to have very high risk of bleeding levels but they're also going to make a lot of red blood cells and whenever you make an excessive amount of red blood cells that's called poli-sci be Nia okay so there also can have polycythemia okay so they have polycythemia increase ventilation increase the rip Whedon production Wow they have a lot of things going on unfortunately that's still not it okay look what else is happening here so again we said increased so what was the things that we said so far so far we've said there's been an increase in ventilation the second thing we said that there was an actual increased number of red blood cells which is called polycythemia polycythemia now for the third thing okay well if you guys remember we're trying to increase the ventilation right this will work we're tempting to do so if you guys think about the alveoli like this let's say here I draw a small alveoli all right here's the alveoli and then here's a small little capillary it's of a small little capillary coming around it right okay right now what have we done we've increased the number of red blood cells right we've increased the number of red blood cells so there's more red blood cells what does that mean for the actual amount of blood that's coming here then there's actually going to be more blood flow so more perfusion coming through right there's a lot more red blood cells that you can oxygenate what else we're trying to do we're trying to increase the ventilation well as you try to increase the ventilation and you increase the perfusion isn't that one of the most efficient efficient ways to have good ventilation perfusion coupling right because what do we say that ventilation / perfusion v / Q is equal to 0.8 if you increase the ventilation you want to couple it so how would you do that because if you increase this it would increase this number you're going to increase the perfusion because if you increase the perfusion you decrease this number so you help it come back to normal range so there's good ventilation perfusion coupling which means what there's efficient gas exchange efficient gas exchange means that you're going to have a very efficient movement of oxygen from the alveoli to the blood and a good movement of co2 from the blood to the alveoli that's amazing - oh my goodness is so cool so again increase ventilation increase number of red blood cells do the polycythemia and because of that there's adequate or we should say normal VQ coupling which means that there's efficient gas exchange all right sweet deal one more this is kind of the one that happens if you are high altitudes for a little bit of a longer time period so if you're at high altitudes for a little bit longer than normal your body does something absolutely amazing okay let's say here's these tissues and what's happening with some of these tissues we've said that normally whenever you're at high altitudes you're developing hypoxemia right so there's not a lot of oxygen delivery normally to these tissues because the low partial pressure of oxygen again this is due to the hypoxemia due to being at high altitudes so you're not getting a lot of delivery to the oxygen tissues I'm sorry you're not getting a lot of oxygen delivery to the tissues so how does your body deal with this okay inside of your blood vessels you have these actual endothelial cells here all right here's your hand Ophelia cells these endothelial cells and other different tissue cells within the vicinity other different tissue cells start producing very amazing chemicals one of the chemicals is called vascular endothelial growth factor and what is this vascular endothelial growth factor so there's that and then there's platelet derived growth factors there's a lot of growth factors that are released what is this basically going to do what it's bringing swings look at this let's say that it secretes this and you actually sprout another blood vessel so coming off of this I'm gonna have another blood vessel it also safe stimulates over here I'm going to have more blood vessels let's say I sprout off of this one I'm going to have more blood vessels sprout off of this one more blood vessels you guys get the point what am i doing I'm making more blood vessels to accommodate for this actual situation in which there's a decreased oxygen delivery what does that call whenever you're making new blood vessels it's called angiogenesis so they're going to have a heavy capillary density so because of this increased vascular endothelial growth factor or platelet derived growth factors all these different types of growth factor chemicals what are they going to do they're going to trigger the production of more blood vessels this is called angio Genesis okay and if they have more blood vessels what does that mean that they have more routes to deliver oxygen to other tissues so it's going to increase the oxygen carrying capacity and delivery to the tissues to accommodate for that decrease in oxygen levels okay so what was the last things last thing was angiogenesis making more blood vessels but this is really long term so this is if you stay up at high altitudes for a little bit longer than normal right another thing is they can if you stay at the high altitudes for a long period of time it can actually change your whole life like if you're actually born at high altitudes it can actually change your hormonal structural chest wall usually people are born at high altitudes they have like a barrel shape chest they have a barrel shaped Chesson they have a very very strong right ventricle and the reason why they have to pump a lot of blood to different parts of the lungs and make sure that it's getting adequately oxygenated okay now that we talked about all these things I want to say what can happen whenever you actually don't properly you know a sin during going to high altitudes you just decide oh I'm going to go full blast I'm going to blaze up that sucker why is this bad as you do this and you don't acclimate okay so what is this process called whenever you stay at these high altitudes for a while - a lot for your body to compensate in a coma Times called acclimatization right so ACK limit eye vision sorry guys I'm of the best speller so acclimatization all right so acclimatization is going to be this basically this time where you stay at high altitudes to be able to compensate a lot for your intercalated b-cells to go to work a lot for this or through putting to go to work angiogenesis all these different things right okay now we've said that whenever you're at high altitudes what do we say it's really really bad because eventually what do we say if there is this respiratory alkalosis we said generally what you're going to try to do you're going to increase your ventilation to get the oxygen levels back to normal but during that process when your increase in the ventilation as you increase the ventilation and because the co2 is an atmosphere is a little bit lower than normal more co2 is leaving so the partial pressure of co2 in the blood decreases which inhibit the central chemoreceptors so there's an opposing ventilation so there's not a lot of ventilation if that happens over a long period of time the hypoxemia can sit can persist for a very long time if it does persist very very long time this low partial pressure of oxygen is extremely dangerous if you watched our microcirculation video you understand why when however there is low partial pressure of oxygen within the systemic blood vessels it triggers vasodilation and whenever there is this vasodilators arriba vessels what is it going to do then it's going to dilate where's this called vaso dilation as there's Veda Basel dilation what happens to the amount of blood flowing through here then there's going to be more blood flowing through if more blood is flowing through the cerebral vessels what does that mean that means that more fluid can leak out because now we're going to have more fluid leaking out here into the actual brain tissue if more fluid is leaking out here into the brain tissue what is that going to do that's going to increase a lot of fluid accumulation in the interstitial spaces and that's going to produce a condition called cerebral edema and this is bad really bad because if it edema can persist for a long period of time or if it becomes so significant it can actually push on the brain and try to cause the herniation of the brain so two things can happen with this if it becomes really bad it can increase the intracranial pressure and one of the signs for intracranial pressures usually have a pounding headache you can have a decreasing of using the situation your pulse rate is actually going to be decreasing your blood pressure is actually increasing and also you can have a lot of nausea problems like that and also the pupils are having a hard time being able to respond to specific light and stuff so high intracranial pressure is extremely dangerous because in cause herniation of the brain why is that dangerous because of the brain hurry eight and compresses the pontine respiratory group or the ventral respiratory group or DRG what's going to happen to the neural impulses they're going to cease will you be able to breathe now you'll go into respiratory arrest and respiratory failure right so that's why it's extremely dangerous again if this actual partial pressure of oxygen persists for a long period of time it can become dangerous dilate the blood vessels going to the actual cerebrum cause more fluid to leak out cause cerebral edema increase the intracranial pressure and cause the herniation of the brain which can damage some of the actual respiratory centers within the brainstem that's why when people go to these high altitudes you make sure I actually asked one my friends he hiked Mount McKinley and he said that when able he went to high altitudes he took a couple different types of medicine ok certain drugs so one of them is actually called a citas Olamide i see this old mine and basically what a c' does old mine does is I remember this enzyme here this carbonic anhydrase it inhibits this carbonic anhydrase and if you inhibit the carbonic anhydrase what it does is it basically helps to be able to mimic and make your body trick your body into thinking that you actually have elevated co2 levels and so if that's the case then you actually can have these elevated co2 levels if you have the elevated co2 levels it will increase your actual ventilation rate so that's one thing they do is they try to take as either acetazolamide but also the first thing that you're gonna want to do if you notice someone having cerebral edema is try to get them on supplemental oxygen so try to get some ice up lament' alloxan so oxygen but if the actual cerebral edema is so bad you're going to want to try to give them another drug which is called mannitol and mannitol is a large molecule and basically what it does is it comes in here and sucks a lot of the fluid out of the actual brain and when it pulls a lot of fluid out it alleviates some of the cerebral edema they also can give another drug called dexamethasone which is basically a cortical steroid which also through some unknown mechanism is able to reduce some of the actual swelling within the brain okay so again you want to make sure that you ACMA ties right another thing that can happen is because the partial pressure of oxygen within the lungs if you guys remember let's say I draw here another small alveoli just real quickly here if there is actually situation in which the partial pressure of oxygen within the alveoli is very low let's say that there's another one another partial pressure of oxygen it's really low if this happens and you have blood vessels coming to this area right so here's a blood vessel here and here's a blood vessel coming right here what's going to happen was a normal response well in the actual systemic circulation it dilates in the actual pulmonary circulation it constricts if they constrict the actual pressure is going to increase right so if it constricts you're going to actually have this pressure increase and over time what happens is over time as this pressure continues to increase in certain areas of the lung some of the actual vessels there's a high amount of constriction in certain vessels so let's assume that let's say that you have a vessel here a vessel here and a vessel here and this one is actually going to have some smooth muscle here this will have some smooth muscle here the pre capillary anchors it's one of the pre-capitalist fingers here let's say this one has heavy constriction this one has heavy constriction so not a lot of blood is going to this one let's say this one has heavy constriction and not a lot of blood is going to this one but let's say this one I only has moderate constriction the actual pre capillary fingers won't contract and what's going to happen in the blood that is not going to these vessels and these vessels are going to be redirected so now it's going to be going through this one some of the blood will be going through this one and some of the normal as we go into this one what happens to the amount of blood flow going to this one little sucker right there he's going to have so much blood flow that fluid is going to start leaking out as fluid starts leaking out into the actual interstitial spaces of the respiratory membrane what is that called this can produce pulmonary edema which obviously can be extremely dangerous because I can impair the gas exchange process okay so now that we understand that pulmonary edema can occur and the cerebral edema can occur these are the two basic signs of whenever someone's experiencing acute mountain sickness okay so if someone has cerebral edema and pulmonary edema how would we classify this we would say that this individual is having acute mountain sickness and again how would you try to treat these people obviously immediately get them away from the high altitudes give them a seat as Olamide erdo max give them supplemental oxygen mannitol dexamethasone and you know make sure that you try to take care of the patient as quickly as possible iron engineer so in this video we covered a lot of information about the respiration of high altitudes I hope it all made sense I hope you guys enjoyed it if you guys did please hit the like button subscribe put some comments down in the comment section as always an engineer until next time

Channel: Ninja Nerd

Views: 185,938

Keywords: respiratory, respiration at high altitudes

Id: P_4wk33cTVo

Length: 43min 33sec (2613 seconds)

Published: Tue Jun 27 2017