You just really helped me to better understand the body's buffer systems. Wasn't really understanding the information presented in the book. This video made it click. Thank you!
A point I’m needing clarification on is this: if CO2 is elevated, it stimulates chemoreceptors and is blown off. But an elevation in CO2 will also shift the equation to the right? So which happens first and/or predominantly? The two concepts seem contradictory, but I know there is a piece I must be missing. Thank you.
Chemical buffering is essentially instantaneous, whereas the chemoreceptor-dependent respiratory response takes a few minutes to get going. Now, here's the deal about those chemorecptors: they don't respond directly to CO2, but rather, H+. But H+ can't readily pass through the endothelial barrier between capillaries and the chemoreceptors, because of its charge (charged, polar atoms or molecules cannot easily pass through membranes which are non-polar). But gases CAN rapidly diffuse across cell membranes, and CO2 is a gas, so it passes out of the blood vessel, and is converted to H+ in the region of the chemoreceptors via the bicarbonate buffer equilibrium getting shifted towards H+ generation. The reaction scheme he gives in the video occurs essentially everywhere in the extracellular compartment and also inside most cells, because carbonic anhydrase is essentially everywhere. Now the chemoreceptors sense the H+ and they then trigger the respiratory response, i.e. increase breathing rate. So, chemical buffering ALWAYS occurs first--it is the primary line of defense, because it acts to limit the free H+ concentration in the same way s sponge works to sop up water. But that sponge will only suck up so much water--if it gets saturated, it won't pick up any more until you wring it out. So you can think of the respiratory and renal responses as sort of "wringing out the sponge," thus restoring the body's chemical buffering capacity.
Thank you so much for providing this video. I am excited in gaining this knowledge because I didn’t think it possible to comprehend before.
You just really helped me to better understand the body's buffer systems. Wasn't really understanding the information presented in the book. This video made it click. Thank you!
Hello Ben, glad I could help
At approximately 21:00 he says a ratio of 20:1 carbonic acid to bicarb but I think it is actually 20:1 bicarb to carbonic acid right?
What is the program that you are use
Underneath where it says "bicorborate butter", is says "caroonie o cicil"? At 10:11 is that latin for something?
i think that says "carbonic acid"
A point I’m needing clarification on is this: if CO2 is elevated, it stimulates chemoreceptors and is blown off. But an elevation in CO2 will also shift the equation to the right? So which happens first and/or predominantly? The two concepts seem contradictory, but I know there is a piece I must be missing. Thank you.
Chemical buffering is essentially instantaneous, whereas the chemoreceptor-dependent respiratory response takes a few minutes to get going. Now, here's the deal about those chemorecptors: they don't respond directly to CO2, but rather, H+. But H+ can't readily pass through the endothelial barrier between capillaries and the chemoreceptors, because of its charge (charged, polar atoms or molecules cannot easily pass through membranes which are non-polar). But gases CAN rapidly diffuse across cell membranes, and CO2 is a gas, so it passes out of the blood vessel, and is converted to H+ in the region of the chemoreceptors via the bicarbonate buffer equilibrium getting shifted towards H+ generation. The reaction scheme he gives in the video occurs essentially everywhere in the extracellular compartment and also inside most cells, because carbonic anhydrase is essentially everywhere. Now the chemoreceptors sense the H+ and they then trigger the respiratory response, i.e. increase breathing rate.
So, chemical buffering ALWAYS occurs first--it is the primary line of defense, because it acts to limit the free H+ concentration in the same way s sponge works to sop up water. But that sponge will only suck up so much water--if it gets saturated, it won't pick up any more until you wring it out. So you can think of the respiratory and renal responses as sort of "wringing out the sponge," thus restoring the body's chemical buffering capacity.
Tom Terific Thank you so much for the thorough explanation
I have used your presentation as a guide for my students. Your acid base series phenomenal.
What is the program that you are use