Acid/Base Flashcards
What reaction does Carbonic Anhydrase catalyze?
CO2 + H2O H2CO3 H+ +HCO3-
Besides bicarb, what are the other buffers?
hemoglobin, PO4-, Albumin
What is a primary side effect of chronic acidosis?
Osteopenia, due to bicarb resorption from bone
What is Kussmaul breathing and why does it happen?
Kussmaul breathing is slow, deep, labored, breaths. It happens because in acidosis there is a rise in H+ ions which drives the CA equation towards H2O and CO2. Kussmaul breathing is how the body blows off the extra CO2 that is produced.
What happens at pH 7.2 and below?
Decrease in cardiac contractility.
Besides Kussmaul breathing and HCO3 resorption from bone, what other effects does acidosis have on the body? [2]
Increased circulating cathecolamine levels
Stimulates protein catabolism –> negative nitrogen balance. Become profoundly malnourished very quickly.
What happens to breathing in an alkalosis?
hypoventilation leading to an increase in CO2
What happens to oxygen and energy production in alkalosis? [2]
The oxygen dissociation curve is shifted to the left thereby decreasing oxygen delivery to the tissues.
Lactate production increases.
How do we produce volatile acids?
By metabolizing the carbohydrates and fats we eat.
How do we deal with volatile acids?
We break them down to CO2 and H2O and excrete them via the lungs
How do we produce and excrete non-volatile acids?
By metabolizing ingested proteins. These are generally sulfur containing acids or hydrochloric acid.
We produce 50-100mEq/day that must be excreted by the kidneys. Lungs can’t metabolize.
What group of people have a very very high level of non-volatile acids to deal with?
Body builders, paleo diet
Given that non-volatile acids are absorbed in the GI tract, how does the body balance acid there?
H+ is excreted on the apical side and HCO3- is extruded on the basolateral side of the gasc.
Why doesn’t the acid/balance in the GI tract change the pH of the body?
H+ is dumped into the lumen and HCO3- is taken up into the serum in the
What must the kidney do prevent chronic acidosis (normal function)? [2] Which type(s) of acid does this apply to?
- reabsorb every single bicarb in the proximal tubule
- Have a way to excrete acid into the urine and reabsorb more bicarb than was consumed.
Trick Question: Both volatile and non-volatile acids. Both consume bicarb to buffer acid
Can the kidneys bind the H+ to bicarb to excrete into urine?
No because it would use up all the bicarb silly.
So then what does the kidney make to carry h+ in the urine? Where is it made?
Ammonium. It’s made in the proximal tubule.
Do proximal tubule cell sense pH?
Yes (through a variety of means)
How does H+ get out of the cell in the proximal tubule?
anti-porter with Sodium
How does ammonium get out of the proximal tubule cell?
antiporter with sodium