Acid-Base Regulation - Quiz 4 Flashcards
What is the Normal amount of H+ in the ECF?
40 nEq/L
The Lower & Higher Limit of pH at which a person can live for a few hours is ___ & ___ respectively.
The Lower & Higher Limit of pH at which a person can live for a few hours is 6.8 & 8.0 respectively.
What is an acid?
Proton Donor
What does the Henderson-Hasselbalch equation describe?
Relationship b/t pH, PaCO2, and Serum Bicarb
What is the Solubility Coefficient for CO2?
0.03 mmol/mmHg
What is a base?
Proton Acceptor
What is the role of Weak Acids or Bases in regards to pH?
Act as Buffers to minimize pH changes
When are pH buffers most efficient?
When pH = pKA
What are the pH Body Buffers?
Bicarb - strongest ECF buffer
Hgb
Proteins
Phosphate
Ammonia
What are the Primary Systems that regulate H+ and Prevent Acidosis/Alkalosis?
Chemical Acid-Base Buffers of Body Fluid
Respiratory Center
Kidneys - slowest, but strongest regulator
True or False: The Bicarb buffer is effective Against both Metabolic & Respiratory acid-base imbalances.
FALSE - Bicarb is effective against Metabolic, but not Respiratory acid-base imbalances
What is the pKa of Bicarb?
pKa = 6.1
How do the Kidneys increase Bicarb Reabsorption during Acidosis?
- CO2 + Water = H2CO3 (Carbonic Acid)
- H2CO3 —> H+ + HCO3-
- H+ secreted into Proximal Tubule & Bicarb is Reabsorbed
- H+ in Proximal Tubule combines w/ Filtered Bicarb = H2CO3-
- Carbonic Anhydrase replaces CO2 by Splitting Bicarb into CO2 & Water
By which mechanism is H+ secreted into the Tubular Fluid?
Sodium-Hydrogen Counter-Transport
How much Filtered Bicarb is reabsorbed in the Proximal Tubule?
80-90 %
The rest reabsorbs in the Distal Tubule