a. Define hyperventilation. b.If you hyperventilate, do you retain or expel more carbon dioxide? c. What effect does hyperventilation have on blood pH?

Video transcript

Hi, everyone. Welcome back. Our next question says, respiratory alkalosis is a condition caused by hyperventilation. Which of the following statements best explains the mechanism of the development of respiratory alkalosis due to hyperventilation. A hyperventilation leads to excessive elimination of carbon dioxide CO2 resulting in decreased levels of carbonic acid in the blood H two co three and increase Ph B. Hyperventilation causes increased oxygen levels in the blood 02 leading to a shift in the acid based balance and increased Ph C hyperventilation enhances the production of bicarbonate ions HCO three minus in the blood leading to increased levels of carbonic acid H two co three and alkalosis D hyperventilation causes a decrease in blood volume resulting in a relative increase in bicarbonate ions, HCO three minus and alkalosis. So let's think about what hyperventilation is. We've got that prefix, hyper reminding us of hyperactive too much and in this case, too much ventilation. So, breathing that is too rapid would be our definition of hyperventilation and it's causing respiratory alkalosis alkalosis meaning the blood ph is too high or too basic. That's as opposed to metabolic alkalosis. The blood ph is too high. You have alkalosis but in that case, the ph imbalances due to metabolic events. So, something about the production or excretion of uh different ions in the blood has thrown off the ph. So what's our mechanism with respiratory Ocu losis? Well, let's just work our way through our answer. Choices. Choice a saying that it leads to excessive elimination of carbon dioxide. Well, this is correct as you're breathing rapidly, you're eliminating, you're blowing out that carbon dioxide much faster than usual. So much more is leaving resulting in decreased levels of carbonic acid in the blood. Well, we recall of course that when carbon dioxide dissolves in the blood, it combines with water to make carbonic acid. So that would lower the ph of the blood. It's, it's a weak acid. When you eliminate too much carbon dioxide, you're exhaling the gaseous carbon dioxide which changes the diffusion gradient of the air and the alveoli. So indeed more of the carbonic acid will diffuse out of the blood. So the levels will in indeed decrease and as acid levels decrease, Ph increases. So choice A is a correct description of this mechanism to be thorough. We'll just look at our other answer. Choices to understand why they're not correct. Choice. B hyperventilation causes increased oxygen levels. Well, along with eliminating more carbon dioxide, you are taking in more oxygen. But then it says leading to a shift in the acid base balance. Well, this is not correct because oxygen does not change the acid based balance in the blood. So this would not be our answer. Choice. Choice c hyperventilation enhances the production of bicarbonate ions. Well, this is not correct. Again, we see hyperventilation causes a decrease in carbonic acid in the blood due to the excessive elimination of CO2. More too many bicarbonate ions in the blood will lead to alkalosis. But that would be a form of metabolic acidosis. Excuse me, metabolic alkalosis can be a little bit of a tongue twister. In addition, you wouldn't expect increased levels of carbonic acid being the result of increased bicarbonate ions. That's a buffer system. So if you have more bicarbonate ions, they're going to soak up those extra protons and decrease your acid level. So choice c not correct and finally choice D hyperventilation causes a decrease in blood volume resulting in a relative increase in bicarbonate ions. Well, hyperventilation does not cause a decrease in blood volume. So we're going to cross that out. So once again, our mechanism of respiratory alkalosis as caused by hyperventilation is choice a that the hyperventilation leads to excessive elimination of CO2 which decreases the level of carbonic acid in the blood, thereby increasing the blood. Ph See you in the next video.