Regulation of Homeostasis by the Kidney: Acid-Base Balance Flashcards
What is a negative feedback loop?
- the bodies way of maintaining homeostasis
- feedback is recieved and the negative feedback encourgaes the body to correct it
What do acids and bases do with H+?
- acid = release into solution
- base = remove from solution
What is generally inevitable if the pH drops below 6.8 or rises above 8?
- death
What is the main buffering enzyme in the body?
- carbonic anhydrase
What 2 systems in the body are able to buffer the pH?
- lungs
- kidneys
The Henderson-Hasselbalch Equation is the reaction caused by which enzymatic buffer in the body?
- CO2 + H2O = H2CO3 = HCO3- + H+
- H2CO3 is carbonic acid
The Henderson-Hasselbalch Equation is:
CO2 + H2O = H2CO3 = HCO3- + H+
- H2CO3 is carbonic acid
Which parts of this equation can be regulated by the lungs and kidneys?
- lungs = PCO2
- kidneys = HCO3-
Why is urine slighhtly acidic?
- body removes excess H+ through urine
- lots of H+ increases acidity
The kidneys are unable to produce urine with a pH below what?
- 4.5
H+ that are present in tubulur cells leave the tubules and cross the apical membrane and into the lumen. In order for H+ to leave the tubule cells what has to enter the tubules through a cotransporter?
- Na+
H+ that are present in tubulur cells leave the tubules and cross the apical membrane and into the lumen in exchange for a Na+ ion moving into the tubulur cells. Once HCO3- and H+ come together, what reaction occurs and what is formed?
- carbonic anhydrase converts HCO3- and H+ into CO2 and H2O
H+ that are present in tubulur cells leave the tubules and cross the apical membrane and into the lumen in exchange for a Na+ ion moving into the tubulur cells. Once HCO3- and H+ come together, carbonic anhydrase converts HCO3- and H+ into CO2 and H2O, which can then freely move into the tubular cells. What then happens to the CO2 and H2O?
- carbonic anhydrase converts CO2 and H2O back into HCO3- and H+
Once HCO3- has made its way into the tubules, how is it able to make its way into the blood capillaries?
- through a Na+ / HCO3- cotransporter
In addition to entering the blood capillaries through a Na+ / HCO3- cotransporter, HCO3- is able to enter the capillaries from the tubules in way, what is this?
- through a Cl- / HCO3- cotransporter
- Cl- leaves the capillaires
If H+ ions are leacing the tubular cells and entering the lumen, this can affect the electronic charge across the membrane. What + ion enters the tubules to balance out the H+ leaving?
- Na+
