42 Questions
What is the primary function of the kidneys in acid-base balance?
Regulating HCO3- levels
What is the term for the primary decrease in HCO3- levels?
Metabolic acidosis
What is the pK value of the bicarbonate buffer system?
6.1
What happens to the pH of the extracellular fluid when base is added to the bicarbonate buffer system?
It increases
What is the primary function of the lungs in acid-base balance?
Regulating PCO2 levels
What is the term for the primary increase in PCO2 levels?
Respiratory acidosis
What happens to the ratio of HCO3- to CO2 when acid is added to the bicarbonate buffer system?
It decreases
What is the bicarbonate buffer system responsible for?
Maintaining acid-base balance
What is the primary mechanism for reabsorption of HCO3-?
HCO3- reacts with a secreted H+ to form H2CO3
What is the total amount of H+ secreted into the tubular fluid daily?
4420 mEq
What happens to HCO3- reabsorption in alkalosis?
HCO3- reabsorption is decreased
What is the primary goal of H+ secretion and HCO3- reabsorption?
To reabsorb all or almost all the filtered HCO3-
In which parts of the tubules does HCO3- reabsorption NOT occur?
Descending and Ascending thin limbs of the loop of Henle
What percentage of HCO3- reabsorption occurs in the proximal convoluted tubule?
80-90%
What is the function of the kidney in regulating extracellular fluid H+ concentration?
To regulate extracellular fluid H+ concentration through three fundamental mechanisms
What is the purpose of secreting an additional 80 mEq of H+?
To expel non-volatile acids produced daily
What is the primary function of the renal system in acid-base balance?
To regulate acid excretion through tubular secretion and reabsorption
What is the term for the amount of acid produced by the body's metabolic processes?
Net Endogenous Acid Production
What is the primary function of Type B intercalated cells?
Secretion of bicarbonate
What is the primary function of the ammonia buffer system in the kidney?
To buffer excess H+ ions
What is the primary mechanism by which the respiratory system regulates acid-base balance?
Through the regulation of CO2 levels
What is the location of V-ATPase in Type B intercalated cells?
Renal interstitial fluid side
What is the approximate amount of phosphate available for buffering excess H+ ions?
30 to 40 mEq/day
What is the result of bicarbonate secretion in Type B intercalated cells?
Alkalosis
What is the term for the condition in which the body has too much acid?
Acidosis
In which state is Type B intercalated cell activated?
When bicarbonate is needed to be secreted
What is the primary role of buffer systems in the body?
To buffer acids and maintain pH homeostasis
What is the primary source of glutamine in the proximal convoluted tubules?
Metabolism of amino acids in the liver
What is the primary active transport system in Type A intercalated cells?
Hydrogen-transporting ATPase
What is the fate of excess H+ ions in the tubular fluid?
They are eliminated and combined with hydrogen phosphate
What is the term for the movement of H+ ions out of the body through the kidneys?
Renal secretion
What is the importance of late tubular segments in acid-base balance?
Formation of maximally acidic urine
What is the term for the amount of acid excreted by the kidneys?
Net Acid Excretion
What is the primary function of the hydrogen phosphate buffer system?
To buffer excess H+ ions
What is the primary mechanism by which the renal system regulates acid-base balance?
Through the regulation of H+ secretion and reabsorption
What is the approximate percentage of H+ ions excreted via the ammonia buffer system?
40 to 50%
What is the mechanism of bicarbonate reabsorption in the kidney?
Secondary active transport
What is the net effect of the ammonia buffer system on the body's acid-base balance?
It decreases the body's acid load
Why is HCO3 reabsorption alone not sufficient for maintaining acid-base balance?
It does not produce new bicarbonate
Where is glutamine primarily metabolized to form bicarbonate and ammonium ion?
Proximal convoluted tubules
What is the fate of the majority of HCO3 formed in the kidney?
It is reabsorbed and enters the bloodstream
What is the role of the ammonium ion in the ammonia buffer system?
It is considered acidic
This quiz covers the physiology of acid-base balance, including renal compensations, definition of terms, and respiratory regulation. It also explores buffers and clinical correlations of acid-base balance disorders.
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