Test Bank Complete_ Guyton and Hall Textbook of
Medical Physiology (Guyton Physiology) 14th Edition
By John E. Hall & Michael E. Hall All Chapters 1-86| 14
Units| Newest Version with all Chapters| With Correct
Answers
Why is it important to regulate H+ concentration in the body? - ANSWERactivity of
almost every enzyme is dependent on H+ concentration
molecules which release H+ ions in solutions are - ANSWERacids
molecules which accept a H+ ion in a solution are - ANSWERbases
define alkali - ANSWERmolecule formed by combination of one or more alkaline
metals (Na, K, Li, etc.)
whats the difference between strong and weak acids - ANSWERstrong acids rapidly
dissociate and released large amounts of H+ while weak acids are less likely to do
that
why do we use logarithm scale when expressing H+ concentration? - ANSWERbcuz H
conc is really low
what is normal pH of arterial blood? - ANSWER7.4
What are the three primary systems which regulate H+ concentration in body fluids?
- ANSWER1) chemical acid-base buffer systems of the body fluids (1st line resisting
change)
2) respiratory center regulates removal of CO2 (2nd line)
3) kidneys excrete acid/base into urine (3rd line, slow to respond)
describe the bicarbonate buffer system equation - ANSWERCO2 +H2O <- -> H2CO3 <-
-> H + HCO3
carbonic anhydrase is the enzyme in charge
adding any of one molecule will shift reaction to the other way
metabolic acidosis/alkalosis is primarily caused by what? -
ANSWERdecrease/increase in HCO3
respiratory acidosis/alkalosis is primarily caused by what? -
ANSWERincrease/decrease in CO2
, when the acid and base components of a buffer are equal to each other, what is the
pH? - ANSWERpKa
what pH is a buffer most effective? - ANSWERAt the buffer's pKa
stops working +/- 1 from pKa
whats the most important extracellular buffer we have? - ANSWERbicarb
what are two reasons why bicarb buffer system is not perfect. How does it still
remain the most effective tool? - ANSWER1) extracellular pH is 7.4, pKa of bicarb
buffer system is 6.1; meaning the system operates on a low portion of the buffering
curve
2) concentrations of CO2 and HCO3 is not particularly high
Our bodies regulate HCO3 and CO2 really well with kidneys and lungs so we have
precise control over rates of addition and removal of HCO3 and CO2
whats the phosphate buffer equation (both acid and base) - ANSWERHCl + 2NaHPO4
--> Na2HPO4 + NaCl
NaOH + NA2HPO4 --> 2NaHPO4 + H2O
what is the phosphate buffer pKa and why is that significant? - ANSWERpKa is 6.8 ,
much closer to 7.4 than bicarb
limitation is low concentration in ECF
more important in the tubular fluids in kidney and ICF
Explain the phosphate buffer in the kidneys - ANSWER1) phosphate becomes greatly
concentrated in tubules, increasing buffering power of phosphate system
2) tubular fluid usually has lower pH than ECF, bringing operating range closer to pKa
6.8 of the system
explain the phosphate buffer system in the ICF - ANSWERconcentration of phosphate
is much higher ICF than ECF
ICF has lower pH than ECF, closer to phosphates pKa
besides phosphate buffers, what else is important in ICF buffering - ANSWERproteins
pKa is similar to ICF pH
Medical Physiology (Guyton Physiology) 14th Edition
By John E. Hall & Michael E. Hall All Chapters 1-86| 14
Units| Newest Version with all Chapters| With Correct
Answers
Why is it important to regulate H+ concentration in the body? - ANSWERactivity of
almost every enzyme is dependent on H+ concentration
molecules which release H+ ions in solutions are - ANSWERacids
molecules which accept a H+ ion in a solution are - ANSWERbases
define alkali - ANSWERmolecule formed by combination of one or more alkaline
metals (Na, K, Li, etc.)
whats the difference between strong and weak acids - ANSWERstrong acids rapidly
dissociate and released large amounts of H+ while weak acids are less likely to do
that
why do we use logarithm scale when expressing H+ concentration? - ANSWERbcuz H
conc is really low
what is normal pH of arterial blood? - ANSWER7.4
What are the three primary systems which regulate H+ concentration in body fluids?
- ANSWER1) chemical acid-base buffer systems of the body fluids (1st line resisting
change)
2) respiratory center regulates removal of CO2 (2nd line)
3) kidneys excrete acid/base into urine (3rd line, slow to respond)
describe the bicarbonate buffer system equation - ANSWERCO2 +H2O <- -> H2CO3 <-
-> H + HCO3
carbonic anhydrase is the enzyme in charge
adding any of one molecule will shift reaction to the other way
metabolic acidosis/alkalosis is primarily caused by what? -
ANSWERdecrease/increase in HCO3
respiratory acidosis/alkalosis is primarily caused by what? -
ANSWERincrease/decrease in CO2
, when the acid and base components of a buffer are equal to each other, what is the
pH? - ANSWERpKa
what pH is a buffer most effective? - ANSWERAt the buffer's pKa
stops working +/- 1 from pKa
whats the most important extracellular buffer we have? - ANSWERbicarb
what are two reasons why bicarb buffer system is not perfect. How does it still
remain the most effective tool? - ANSWER1) extracellular pH is 7.4, pKa of bicarb
buffer system is 6.1; meaning the system operates on a low portion of the buffering
curve
2) concentrations of CO2 and HCO3 is not particularly high
Our bodies regulate HCO3 and CO2 really well with kidneys and lungs so we have
precise control over rates of addition and removal of HCO3 and CO2
whats the phosphate buffer equation (both acid and base) - ANSWERHCl + 2NaHPO4
--> Na2HPO4 + NaCl
NaOH + NA2HPO4 --> 2NaHPO4 + H2O
what is the phosphate buffer pKa and why is that significant? - ANSWERpKa is 6.8 ,
much closer to 7.4 than bicarb
limitation is low concentration in ECF
more important in the tubular fluids in kidney and ICF
Explain the phosphate buffer in the kidneys - ANSWER1) phosphate becomes greatly
concentrated in tubules, increasing buffering power of phosphate system
2) tubular fluid usually has lower pH than ECF, bringing operating range closer to pKa
6.8 of the system
explain the phosphate buffer system in the ICF - ANSWERconcentration of phosphate
is much higher ICF than ECF
ICF has lower pH than ECF, closer to phosphates pKa
besides phosphate buffers, what else is important in ICF buffering - ANSWERproteins
pKa is similar to ICF pH
