What is the normal pH of the plasma/ECF?
What is the normal pH of the arterial blood?
What is the normal pH of the venous blood?
6.8 - 8.0
What is the range of pH that can be tolerated by the body?
The clinical term for a pH less than 6.8
The clinical term for a pH greater than 8.0
depression of CNS, disorientation, coma
What are the symptoms of acidosis?
What are the symptoms of alkalosis?
nutrients, metabolism, carbonic acid
What are the three sources of acids in the body?
What sort of acids come from nutrients?
sulfuric acid, phosphoric acid
What are two examples of inorganic acids?
What sort of acids come from the metabolism?
fatty acid, lactic acid
What are two examples of organic acids?
What is the chemical representation of carbonic acid?
What is H2CO3?
chemical buffers, respiratory system, kidneys
What are the three mechanisms for regulating acid/base balance in the plasma?
Over what timeframe can chemical buffers have an effect on acid/base balance?
seconds to minutes
Over what timeframe can the respiratory system have an effect on acid/base balance?
hours to days
Over what timeframe can the kidneys have an effect on acid/base balance?
carbonic acid, haemoglobin, phosphate buffers
What are the three main chemical buffers in the body?
Which is the most important buffer in the blood?
proton + bicarbonate
What chemical reaction forms carbonic acid?
What is the chemical representation of bicarbonate?
What converts carbonic acid to water and carbon dioxide?
water and carbon dioxide
What is carbonic acid converted to?
all of them!
What acids do the kidneys deal with?
H+ excretion, HCO3- excretion, NH3 excretion
What are the three mechanisms by which the kidneys regulate the pH of the ECF?
NH3 is known as...
increased plasma [H+] or [CO2]
What two triggers do the kidneys respond to in acidosis?
increased H+ secretion, increased HCO3- reabsorption
What are the two reactions of the kidneys to acidosis?
buffer H+ and CO2
Why is it beneficial to have increased [HCO3-] in the plasma during acidosis?
In normal daily excretion, where in the kidney are H+ and HCO3- regulated?
Apical membrane protein in the proximal tubule cell important in daily pH regulation
Basal membrane protein in the proximal tubule cell important in pH regulation
proton + bicarbonate - carbonic acid - water + carbon dioxide
What is the reaction that takes place in the proximal tubule cell and in the lumen in normal daily excretion?
What percentage of bicarbonate is reabsorbed in the kidney in normal daily activity?
What is the initial pH of the filtrate?
What is the pH of the filtrate at the end of the proximal tubule?
late distal tubule and cortical collecting ducts
In metabolic acidosis, where are H+ and HCO3- regulated?
production of new HCO3-
What is the primary way the kidney combats metabolic acidosis if there is some bicarbonate remaining?
water + carbon dioxide - carbonic acid - proton + bicarbonate
What is the reaction that takes place in the LDT/CCD cell in metabolic acidosis?
excreted in urine
What happens to the additional protons created when producing new bicarbonate in the LDT/CCD?
4 - 4.5
What is the minimum pH of urine?
What is the primary way the kidney combats metabolic acidosis if there is no bicarbonate remaining?
Where does secretion of NH3 take place in the kidney?
What is the apical membrane protein in the proximal tubule cell important in secretion of NH3?
glutamine - ammonium and bicarbonate
What is the reaction that takes place in the proximal tubule cell in metabolic acidosis?
absorbed via basal HCO3--Cl- exchanger
What happens to the bicarbonate that is generated by the proximal tubule cell in metabolic acidosis?
disassociates into ammonia and protons to cross membrane into lumen
What happens to the ammonium that is generated by the proximal tubule cell in metabolic acidosis?
Cl- + NH3 + H+ goes to NH4Cl which is excreted
What happens to ammonia and protons in the lumen of the proximal tubule cell in metabolic acidosis?
What is the chemical representation of ammonium?
What is NH4+?
What is excreted by the kidney in alkalosis to regulate the pH?
not enough H+ to interact with it
Why isn't bicarbonate absorbed in the kidney in alkalosis?
What do the intercalated type B cells in the LDT/CCD do during alkalosis?