Describe the role of the respiratory system in controlling acid-base balance.

Video transcript

Welcome back everybody. Our next question says which of the following is not part of the respiratory systems mechanism for maintaining acid based balance. When the partial pressure of Co2 rises in the blood A, it increases the respiratory rate. B it increases the clearance of Co2 C, it reduces H plus ion concentration or D, it reduces the ph of the blood. Well, the key thing to understand here is that when CO2 increases the PH of the blood decreases and that is because CO reacts with water to make carbonic acid H two co three. And anytime you hear acid, you know that that will dissociate to produce H plus ions which will lower the ph of the blood. So as Co2 levels increase, the blood becomes more acidic. So how does the respiratory system contradict that and maintain a Ph balance while these high H plus concentrations trigger chemo receptors in the brain? So you start to have cerebral acidosis due to the high of more acidity in the blood that affects the brain that triggers these chemo receptors, which then cause an increase in the rate and depth of respiration. So, breaths are coming faster and are deeper, more air is being drawn in and expelled. And that will end up increasing the amount of CO2 that's expelled from the body. And of course, if we're getting rid of more CO2 RPH will increase. So that's the reactions that are going on or the mechanisms that are going on to balance that Ph when CO2 levels rise. So when we look at our answer choices, the one that would be not part of this is choice D, it reduces the ph of the blood because we've seen right here that the PH increases as a result of this mechanism the body has. When we look at our other answer, choices. Choice A it increases the respiratory rate. Well, yes, it does. That's what the brain does in response to that high acid levels. Choice B increases the clearance of CO2 that's done by increasing the respiratory rate. And choice C it reduces H plus ion concentration that happens because more CO2 is cleared from the blood. So that's why choice C isn't our correct answer? And our answer is choice D it reduces the ph of the blood. See you in the next video.