Describe the role of the respiratory system in controlling aci...

Question

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

Accepted Answer

Welcome back, everyone. Which of the following is not part of the respiratory response. When blood ph drops a chemo receptors in the brain's respiratory control centers are activated b breathing rate and depth decrease. C more carbon dioxide is removed from the blood or D proton concentration decreases. Let's start by recognizing that when blood ph is low, this can lead to acidosis and how this occurs is by the following mechanism where respiration or the rate of breathing decreases, which is followed by less carbon dioxide being cleared from the body due to decreased exhalation and decreased inhalation of oxygen. This is then followed by an increase in the concentration of protons in the blood. And this is due to the fact that recall that carbon dioxide reacts with water in the body in order to form carbonic acid as a product. And this is going to be an equilibrium because this can happen in either the Ford or reverse direction and that is due to respiratory gas exchange during exhalation. Now recall that carbonic acid is considered a weak acid and recall that weak acids will only partially dissociate. So it will be in an equilibrium with its constituted ions where we've got two moles of protons as a product along with one mole of carbonate as a second product, co 32 minus. And so, as carbonic acid dissociates, we can observe the increase in concentration of protons in the blood. So that explains that part and upon the increase in concentration of protons leads to a further decrease of the blood ph. But according to the prompt, we need to determine the respiratory response as a result of the ph of the blood dropping. And so the respiratory response is going to actually involve, we'll say response. It's going to involve the Mela Alan recall that the Mandula Alan controls respiration and actually a better better word would be, it regulates respiration. And this is because recall that it's a region located in the brain stem and recall that it contains sensitive chemo receptors that are central in the medulla. And recall that these chemo receptors are going to be sensitive to changes in carbon dioxide or in the concentration of carbon dioxide. And this concentration of carbon dioxide would be specific to the cerebrospinal fluid, which recall is influenced by blood ph. So especially in the case of when blood Ph drops, which can lead to acidosis of the blood, these chemo receptors are then going to signal the respiratory muscles, including the diaphragm and the intercostal muscles to ultimately increase the rate and depth of breathing. So that means then an increase in respiration. And we'll actually write that over here so that we have room, an increase in respiration would then be followed by an increase in carbon dioxide being cleared from body, which will mean that there is less carbon dioxide present to react with water to form that carbonic acid which would dissociate into protons. And so that means a decrease in the concentration of protons in the blood and therefore an increase in blood. ph because recall that protons are acidic and so a lower concentration of protons means a higher P for the blood. And so based on our answer, choices, the respiratory response being proton concentration decreasing in choice D is a correct response. So because we want the choice that is not a part of the respiratory response, we're going to rule out choice D then looking at choice C, more carbon dioxide being removed from the blood is also going to be a part of that respiratory response to address the drop in blood ph. And so we would also rule out choice C because it is a part of the respiratory response. And then the in choice A or rather choice B says breathing rate and depth, decrease the respiratory response to blood ph dropping will be that breathing rate and depth should increase. So that more carbon dioxide is cleared from the body. So B we are going to rule out because it is a part of that respiratory response. And then a the chemo receptors in the brain's respiratory control centers are activated. As we stated, that is a part of the respiratory response when blood Ph drops, because respiration is regulated by the Mela Ada and we would need increased respiration in order to raise that blood ph. And so actually going back, so ruling out choice A and going back to choice B I misread it and it's the breathing rate and depth decrease. It should actually state that the breathing rate and depth should increase in order to increase that blood ph. And so because it states that breathing rate and depth should decrease, we would actually not consider choice B as a part of the respiratory response when blood Ph drops. And so B is actually going to be the final answer to complete this example as the only choice that is not a part of the respiratory response when blood Ph drops. So this is our final answer. I hope this made sense and let us know if you have any questions.

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

Key Concepts

Respiratory System Function

Acid-Base Balance

Carbon Dioxide and pH Relationship

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