okay so I'm going to be talking about the bicarbonate buffer system and its role in metabolic and respiratory pH imbalances so first let's talk about what PH is well it's a scale from 1 to 14 one being acidic uh 14 is basic and your blood is just about seven if you're basic you have less hydrogen ions and if you're acidic you have more hydrogen ions so high pH is a low hydrogen ion concentration and a low ph is a high hydrogen ion concentration so here's an equation and on the left we see that CO2 is acidic and on the right we see that hydrogen is acidic and bicarbonate is basic it can actually be both but let's not worry about that so here's that equation again on the left side it represents the lungs because the lungs decrease acid by increasing rests which decreases CO2 which is acidic because you're breathing it out on the other side uh this represents the kidneys because this is the part that the kidneys take care of and they decrease acid by peeing out hydrogen ions and secreting bicarbonates so basically putting base into the blood so basically on the left hand side the CO2 lungs are respiratory so the lungs are not keeping up causing acidosis or alkalosis when this happens the kidneys start to help help out to or otherwise compensate so basically respiratory acidosis your lungs aren't getting enough getting rid of enough CO2 and that builds up causing acidosis and your kidneys compensate by secreting a base bicarbonate and trying to get rid of the excess hydrogen ions which are acidic in alkalosis your lungs are breathing too much and getting rid of too much CO2 or acid and the kidneys will compensate by reabsorbing their base the bicarbonate into special containers and not secreting the hydrogen so in short here less breathing is more CO2 which is more acid which is respiratory acidosis so low ph is more acid and high CO2 because it is acid and it's compensated with a high bicarbonate which is the base and the other way around of course more breathing less CO2 less CO2 is less acid and the kidneys help and store their base and not pee out the acid so this is alkalosis a high pH with low CO2 which is compensated by low bicarbonate all right so on the other side we have the kidneys so if this is affected it's metabolic the kidneys can't do their job to regulate PH as acid builds up in the bodies the kidneys aren't secreting enough uh hydrogen or secreting enough uh bicarbonate so the question is why does the bicarbonate go down well because what is left in the system is being bound to the free hydrogen to make the equation go to left so the lungs can compensate but the kidneys are too slow to secrete the bicarbonate to keep up demand especially because in this case they're sick and not functioning properly which is causing the problem so but to compensate the lungs are now going to change the resp rate to try to help out if they're acidic they're going to breathe more and if they're alkalic they're going to breathe less so again in short kidneys can't function which is causing the pH imbalance in metabolic acidosis the hydrogen ion concentration is too high the pH too low and the bicarbonate is too low or the other way around when the kidneys are perhaps secreting too much hydrogen or secreting too much bicarbonate because it takes them longer to adjust we get alkalosis so it's a low hydrogen concentration High bicarbonate high pH compensated with CO2 so essentially the point is the kidneys are slow at fixing and the lungs are faster at fixing so that's important to keep in mind and remember Co if the CO2 is off it's going to be respiratory problem if the bicarbonate is off it's a metabolic problem both are off there's some sort of compensation and if the pH is a higher low normal it means it's fully compensated so now if you're ready for some examples you can watch part two created using pun