and so when we look at this volume stuff we look at what goes in and out of the lungs how much air goes in and out lungs we actually have a large variety of how much you know l a large uh variety of air that goes in and out we we we normally just breathe about half a liter in and out that's about a p a single breath during a quiet breathing is about is about a pint of fresh air that goes in and we call that thing the title volume but that's very small compared to the total combined long volume because that's about 5 liters that's more than a gallon so we compare a pine to a gallon so we can therefore vary as much as we want to what we bring in and out so after we inhale quietly we can bring in other two and a half more liters into the lungs and we call that the inspiratory reserve volume and then when we want to Exhale more than what we normally exhale we call that the expiratory reserve volume so what's important here is to understand look at this graph look at this graph the little Wiggly up and down in the middle that's the title volume that's in and out when we sit down and don't do anything now after the title volume if you want to have more coming in that's then called The inspiratory Reserve volume it's after we sit down quietly and inhale otherwise we can't calculate it and then after we exhale and then we want to Exhale more look over here we have the expiratory reserve volume that's described right here that we can expire more that's about a liter and a half all right so that's the graph basically and then all together combined the from all full exhalation anything out you can get out to a full inhalation everything you can get in is about this it's the vital capacity that's what's called the vital capacity that's over here the maximum volume of a single breath is the vital capacity it can be measured by a spirometer and the spirometer is an instrument that consists of a gas tied chamber that's attached to a tube to the mouth measuring the volume going in and out of the lungs even though after we fully expire we have some gas that remains inside the lungs to keep the air is open and patent and that's known as the residual volume that's right here that's the bottom one when we go back to the other Slide the residual volume you see that that's right here residual volume at the bottom that's about 12200 uh milliliters and then air reminding in the air passages that does not contribute to the gas exchange so that's the air that we have in the tracheo that we have in the fairings that is the air never reaching the lvi also in the brona we have that and that is about 150 milliliters that's not that much and that's known as the anatomical de space that's where that's in anatomical de space okay that brings us to the Alvi the Alvi are air sacks that are mostly composed of alve cells those are type one num numo sites so whenever you see something says numo is um long stuff and they Li on a basement membrane those are um numo sites they have a basement membrane and then the basement membrane that's where the capill is closely cling to them and then in addition to that we have type two numos sites and those are actually cells that are different what they do is they secrete a surfactant and a surfactant the what's suror well let's think about this we have these alvite cells these first pyes they are they are a watery type they have a lot of they're they're they're they're having a tension on the surface that that if those cells are too small and too close together they collapse and fold in on each other and so in order for that not to happen we have to have cells interspersed that are phospholipid cells they are they are cells that are sort of fatty cells they break down that surface tension and so they create a phospholipids that contain coating the interior of the Alva and reducing that surface tension that is created and so that prevents an alv or collapse and so in the old days that actually was a determining Factor if a baby is viable or not because if the cells the long cells do not make Al or uh do not make surfactant yet we couldn't be viable because we couldn't Harbor oxygen from the environment we would have to get it from the mom uh but now we have um we have we can make it synthetically so we have much better abilities to change to to to work with that and then we have a third type in the LV thir third cell type and those are dust cells and those are alv mcroof fores they keep the lvi clean so I like those because the ver dust and I can combine that fast with the ver vacuum and then I know those are the ones that keep me clean in there in the lungs so we have um alv cells num sites type one piz type two that are surfactant cells and then the dust cells um in there so when we then the gas exchange uh actually occurs in the LVL themselves where the respiratory gas diffus through the Blood air barrier we can call that the alv capillary membrane go these complicated words huh the driving force of that gas exchange that's the important part the driving force is the partial pressure of the specific gases what's that well we have the whole air and the whole air is composed of all these different gases not just oxygen it also has other stuff in it and the partial pressure is within the air is the pressure of oxygen molecules and so when we say partial pressure we just look at oxygen pressure within that big air mixture and the partial pressure difference between the outside air air in the Alvi and the air in the blood or the oxygen partial pressure in the blood determines the flow of a specific gas going in and out either going in or going out so in Oxygen's perspective when the deoxygenated block comes by thei there is much more oxygen in the Alvi look at this um oxygen look at this 104 mm per Mercury that's a lot of pressure mmhg that's just figuring out pressure stuff that's when they take blood pressure it's the same thing and then look at the O2 inside the Venus blood that's only 40 mm per Mercury so that's much lower so now this oxygen wants to go right in here and look at here on the arterial side I mean on the oxygenated side of the blood we have 104 so it balances right out the oxygen gets right sucked into the blood so that's great so actually that's the hemoglobin the hemoglobins are like magnets they sucked that oxygen right into it and then with in terms of the carbon dioxide we go from inside Venus SP 45 millimeters here's about 40 inside the air and then here's about 40 so we we we don't have that grave that big of a difference in with with the with the carbon dioxide in there but that's what that is all about so how we going to have that gas exchange and then the respiratory gases so that oxygen travels bound to the hemoglobin so so it's attached to the hemoglobin the amount of oxygen saturation depends on the partial pressure of oxygen that's the P2 in there in the text the higher that partial pressure is the more oxygen is carried in the blood and now we're figuring out of dissociation of the oxygen by the hemoglobin because what happens now is we have that magnet that holds onto that oxygen and we got tissue now we have talk about the internal respiration now then we got tissue that needs the oxygen and how easy it is to get that oxygen into the tissue can be very helpful and so we have this sociation of oxygen by the hemoglobin and that happens when the partial oxygen the partial pressure of oxygen um on the hemoglobin is about 50% and so this is uh or more but this facilitates the delivery of oxygen to the tissue uh in greatest need of it so when we when we get this oxygen to that area to that tissue it dissociates and it dissociates more when the tissue is in Greater need and that's described up here with this dissociation curve when the pH for example is low when the tissue is acidic that oxygen goes right into the tissue because that means there is more CO2 in the tissue and that means that tissue has used a lot of oxygen and will need more oxygen fast you're running around that's your muscle cells right yeah temperature goes up that means the metabolism goes up when you run around you create more heat these muscle cells need more energy they need more oxygen therefore that also helps the oxgen get into the tissue faster and we have the partial pressure of carbon diox oxide is also an indicator because that also indicates we have used more oxygen and then this p23 p p BPG is more complicated that's a molecule that attaches to the hemoglobin and so we measure also how much oxygen is attached to the hemoglobin that way and so that's an interesting sort of way how we can be very very fine- tuned of where the oxygen goes down to what the tissue envir is ver that hemoglobin Travels by so I really like that a lot I know it's a little complicated but I think you get some of that and then carbon monoxide is is a player that uh we want to also bring in here because that has a great Affinity to the hemoglobin actually it has a greater Affinity to the hemoglobin than oxygen has and so that is very difficult to work with so if we have actually carbon dioxide in the system that attaches to the hemoglobin and so when there is too much used up we don't have any space left for the oxygen to attach to and so then we have carbon monoxide poisoning and that's difficult to spot because it looks like the hemoglobin is all happy it's the same bright color as when we have an oxyhemoglobin when the hemoglobin is attached with the oxygen and so we can't even see it really we can see a little bit in this picture down here at the bottom because the Cherry skin uh red skin is is produced by that you can see that what we can see about EES here is when we don't have enough oxygen on in the tissue on the blood and that's hypoxia that's de oxygenated blood and that looks darker bluish red versus bright red and so when we when we see purple discoloration this sinosis here in the lips the hands and the feet like here when the kids too long in the water that's why we get them out we can spot a hypoxic situation um anoxia is when we don't have sufficient oxion going through the cells and clob fingers like that can be an indication of that when we control the breathing the respiratory movement in the chest are what does the breathing the the external intercostals and then the diaphragm that's coordinated by rhythmic excitation of nerve cells in the medulla oblong we have the medulla oblong oh the medulla oblong again right is the bottom part of the brain stem so that's down here then the Palms is a bit further up that's right in front of the cerebellum in the back here the cifi brain so then we have inspiratory nerves in here and and we also have expiratory nerves or neurons the inspiratory neurons activate the muscles of inspiration until then stretch receptors inside the lung reflexively in inhibit them and stimulate expiratory neurons and so they go in a cycle like that and then in the pawns above above here we have paltin nuclear and they further regulate and fine tune the force and the depth of breathing the partial pressure of oxygen and particularly the partial pressure of carbon dioxide in the blood cells as well as the arterial pH influence the respirat rate and the depth of breathing as well we have chemo receptors in the aorta we have them in the cored arteries which are the arteries that go into the head which is great because we need a lot of oxygen in the head um but we also have them uh near the respiratory Center inside the central nervous system so that's inside the the um inside the medulla bada and they continuously monitor the blood concentration of various chemicals particularly CO2 and oxygen and I'm breathing um gets influenced by that so it can it can change uh uh when we pick up a problem in there we also of course have a breathing change when we're upset we can feel that or when we're in pain or when it's temperature that's different or when we like go running around and do a lot of muscular work all right I think that's it wow that was a lot hope you learned something see you later