respiratory acidosis and alkalosis

[junaidyounis]

due to hypoventilation there in increase in paco2 in body and there iss NET INCREASE OF H+ resulting in respiratory acidosis. and seeing equation CO2 (g) + H20 (l) <=> H2CO3 (aq) <=> H+ (aq) + HCO3- (aq ) it shifts to right to increase co2. as we see both H+ and HCO3 are formed equally so how come there is net increase of just H+ as HCO3 are also formed along with H+.my point is when H+ and HCO3 ratio formed is equal then why come net increase is just H+. so how come acidosis accour. your help will be great coz im stuck

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[Apoplexy__]

Edit: Sorry, thought I knew, but I don't. Now I'm curious...

 

[PEPISSESCE]

H+ is a strong acid and HCO3- is a weak base , so possible that ,stronger one (H+) increase overwhelms the weaker one's..

 

[syma]

It isn't quite like that. It is compensated by the bicarbonate ions that are already present on the blood. Your kidney will attempt to reabsorb more bicarbonate and make more, But this process can take a couple of days to occur.

You would know it is respiratory acidosis but looking at your ratio of carbon dioxide to bicarbonate ions, and additionally the concentration/partial pressure of carbon dioxide. That is how your pH is changed.

Your [bicarbonate] is pretty stable, so any increase or decrease in your carbon dioxide will change the pH. Also remember that there are far more bicarbonate ions present in the blood than carbon dioxide.

Hope that helps

 

[junaidyounis]

It isn't quite like that. It is compensated by the bicarbonate ions that are already present on the blood. Your kidney will attempt to reabsorb more bicarbonate and make more, But this process can take a couple of days to occur.

You would know it is respiratory acidosis but looking at your ratio of carbon dioxide to bicarbonate ions, and additionally the concentration/partial pressure of carbon dioxide. That is how your pH is changed.

Your [bicarbonate] is pretty stable, so any increase or decrease in your carbon dioxide will change the pH. Also remember that there are far more bicarbonate ions present in the blood than carbon dioxide.

Hope that helps

if i am not wrong the proton formed in respiratory acidosis is never buffered by bicarbonate. so there is never decrease in bicarbonate in respiratory acidosis like in metabolic acidosis. H+ is buffered by intracellular hb....

 

[syma]

if i am not wrong the proton formed in respiratory acidosis is never buffered by bicarbonate. so there is never decrease in bicarbonate in respiratory acidosis like in metabolic acidosis. H+ is buffered by intracellular hb....

I haven't used the word buffered, because it is not technically buffering.
your hydrogen binds to haemoglobin and exchanges chloride ions for bicarbonate ones, increasing the levels of bicarbonate to try to cope with the increase in carbon dioxide to try to maintain your ratio of bicarbonate/carbon dioxide.

It is this ratio that is used to calculate pH.

Any respiratory change is compensated by the kidneys.

Metabolic change is compensated by ventilation.

 

[solitarius]

Acidosis = low pH. pH only measures [H+] in solution without regard for [HCO3-]. The only way for [HCO3-] to affect the pH is to react with H+ to form carbonic acid.

With acidosis, that's not possible because there's too much CO2 in the system, which will drive the equilibrium towards the right side: CO2 (g) + H20 (l) <=> H2CO3 (aq) <=> H+ (aq) + HCO3- (aq ).

 

[syma]

Acidosis = low pH. pH only measures [H+] in solution without regard for [HCO3-]. The only way for [HCO3-] to affect the pH equation is to react with H+ to form carbonic acid.

With acidosis, that's not possible because there's too much CO2 in the system, which will drive the equilibrium towards the right side: CO2 (g) + H20 (l) <=> H2CO3 (aq) <=> H+ (aq) + HCO3- (aq ).

In your standard Henderson-hasselbalch equation, yes you will use your concentration of hydrogen ions. However, since in your blood gases and other clinical biochemistry you cannot measure that alone, you can use the following equation attached.

pH = pK + log ([bicarbonate]/[carbon dioxide])

Your concentration of carbon dioxide is calculated using your partial pressure of carbon dioxide using your coefficient of solubility.

 

[solitarius]

If you read what I wrote, I implied that other gases can affect the pH by reacting with H+. Furthermore, your equation is merely a logarithmic transformation of the equation I referenced (i.e., it's exactly the same).

However, pH is strictly a measurement of [H+] in blood.

 

[syma]

If you read what I wrote, I implied that other gases can affect the pH by reacting with H+. Furthermore, your equation is merely a logarithmic transformation of the equation I referenced (i.e., it's exactly the same).

However, pH is strictly a measurement of [H+] in blood.

Indeed, I did read what you wrote. You stated that pH of the blood is 'without regard' of bicarbonate ions, when my earlier replied indicated the ratio being bicarbonate and carbon dioxide being important in the calculation of blood pH. Perhaps I am incorrect in my understanding with what you meant by "without regard".

It would appear we are saying the same, and I did not intend on a disagreement.

Thanks.

 

[junaidyounis]

I haven't used the word buffered, because it is not technically buffering.
your hydrogen binds to haemoglobin and exchanges chloride ions for bicarbonate ones, increasing the levels of bicarbonate to try to cope with the increase in carbon dioxide to try to maintain your ratio of bicarbonate/carbon dioxide.

It is this ratio that is used to calculate pH.

Any respiratory change is compensated by the kidneys.

Metabolic change is compensated by ventilation.

thank you so much.now i have a better idea of this concept

 

[junaidyounis]

It isn't quite like that. It is compensated by the bicarbonate ions that are already present on the blood. Your kidney will attempt to reabsorb more bicarbonate and make more, But this process can take a couple of days to occur.

You would know it is respiratory acidosis but looking at your ratio of carbon dioxide to bicarbonate ions, and additionally the concentration/partial pressure of carbon dioxide. That is how your pH is changed.

Your [bicarbonate] is pretty stable, so any increase or decrease in your carbon dioxide will change the pH. Also remember that there are far more bicarbonate ions present in the blood than carbon dioxide.

Hope that helps

i understood your point on ratio of co2 to bicarbonate and recalling the mechansim. one last thing additionally you said we see ratio of the concentration/partial pressure of co2...could you elaborate it a bit more... your explanation has already helped lots .. just some more will make it crystal clear