I've read in an article that due to buffering of non-volatile acids in plasma, bicarbonate is consumed and essentially exhaled as CO2, which causes a net bicarbonate loss.. so this is basically what the kidney is doing? It reabsorbs all of the bicarbonate, but additionally has to compensate for that bicarbonate loss (through exhalation) by secreting acid (“de novo” bicarbonate production in the proximal tubule and collecting ducts by excreting acid as H2PO4- and NH4+)? Did I understand that correctly? Thank you for the great videos! They help me a lot in medical school!
@@aamirkhan18111 but the lost bicarbonate, that has to be replaced via de novo synthesis by the kidneys, is lost via exhalation as CO2 right? Isn't it like that, that in a sense the kidney excretes acid basically by generating bicarb?
@@aamirkhan18111 That's exactly what I said in my initial comment :D You loose bicarbonate during buffering (which is exhaled in form of CO2; notice I'm not saying that acid is exhaled! I'm saying we loose buffer capacity), which has to be created “de novo” by the kidneys in order to compensate for the lost bicarb
Hello, I have a question about the 70mmol/H+ produced. You said that 20 is from diet, 40 from metab and 10 is from excretion. How is excretion a plus? Do you mean the 70mmol is including all H+ produced even if it is not retained in the body, and the excretion is its final function? Thank you.
The thing is that excreting bicarbonate is equivalent to gaining acid. A healthy person looses virtually none of the bicarbonate that's filtered by the glomerulus! Most of it is reclaimed in the proximal tubule, some in the more distal nephron.
