Exam 4: Lecture 49: Acid base terminology Flashcards
What are the three chemical buffer systems?
Bicarbonate, phosphate, and protein
What are the two physiological buffer systems?
Respiratory and Renal
Which type of buffering system is the first line of defense against a pH shift?
Chemical buffer system
Which type of buffering system would have an immediate response to an increased H+ load?
Extracellular buffering by HCO3-
Which type of buffering system takes the longest to get rid of the excess H+?
Increased renal excretion of H+
Why is the HCO3-/CO2 a better buffering system than the H2PO4-/HPO4-2 system?
- HCO3- is in a higher concentration than HPO4-2
- HCO3-/CO2 makes CO2 which is volatile and be excreted by the lungs.
What are the four types of intracellular buffers?
- bicarbonate-carbonic acid
- hemoglobin
- proteins
- organic phosphates
T/F: Respiratory buffering mechanisms work with both volatile and fixed acids.
False - they only work with volatile acids
What is a major advantage to renal buffering systems?
The kidneys eliminate large amounts of acid
If the kidneys fail, what happens to the pH?
pH balance fails causing acidemia
What are the two substances the kidneys excrete in the elimination of fixed acids?
- Titratable acid
- Ammonium
What enzyme breaks down H2CO3 into CO2 + H2O in the lumen of the proximal tubule?
Carbonic anhydrase
In the excretion of titratable acid, which acid is excreted?
H2PO4-
