Acid Base Flashcards
What is the main goal of acid base
Maintaining the bodies normal acid concentration
How is acid base balance achieved?
- Buffers (in ECF and ICF)
- Respiratory mechanisms that excrete CO2
- Renal mechanisms that reabsorb bicarb and secrete hydrogen
What is normal arterial blood range
7.37 to 7.42
Is arterial pH slightly acidic or alkaline?
Alkaline (even tho metabolic processes secrete acid)
What are non-volatile/fixed acids, and example
- Acid is acid and it doesn’t change
- Ex= Sulfuric acid and phosphoric acid
What are volatile acids and example
CO2
-these acids are changeable
What are examples of abnormal fixed acids of the body
- Ketoacids
- Lactic acid
- Salicylic acid
- Formic acid
- Oxalic acid
What is the end product of aerobic metabolism in cells
CO2
Is CO2 along an acid
NOPEEEE
What is the equation for buffers
CO2 + H20 =H2CO3 = H + HCO3
What is the path of CO2 in the body
- Produced by cells
- Enters venous circulation
- Carried to the lungs to be expired
How are fixed acids excreted
-Filtered by the body fluids until they can be excreted into the kidneys
_____ helps the body fluids resist a change in pH
Buffer
What are 2 extacellular buffers
- Bicarb
- Phosphate
Acidemia stimulates ________ and produces an immediate increase in the ventilation rate (aka kusmals breathing)
central chemoreceptors
What is the role of the kidneys in acid base balance
- Excrete H
- Replenish HCO3
What are examples of intracellular buffers
- Organic phosphtaes
- Proteins (hemoglobin)
To utilize intracellular buffers, acid base disturbances have to….
Cross the cell membrane by 1 of 3 mechanisms
What are the ways that acid crosses the cell membrane
-Respiratory acid base disturbances
(CO2 enters the cell and is buffered by intracellular buffers)
-Excess or deficit of fixed acids
(Lactic acidosis- hydrogen and lactate enter the cell together)
-H exchanges with K
What do the kidneys do?
- Reabsorb filtered HCO3
- Excrete fixed acids
How much of filtered bicarb is reabsorbed by the kidneys
99.9%
What is the filtered load of bicarb the product of…
GFR*Plasma bicarb
When does the kidney stop reabsorbing bicarb
When plasma bicarb is over 40
What is H secreted with urinary buffers
Titratable acid
What is the most important of the inorganic buffers
Inorganic phosphate
H is secreted from the cells into the lumen where it combines with _______ to make H2PO4
HPO4 -2
Describe renal failures effect on metabolic acidosis
- Titratable acid excretion is decreased because GFT is reduced
- NH4 excretion is decreased second to impaired synthesis of NH3 in diseased renal cells
What type of diet should people with renal failure be put on to reduce fixed acid production
Low protein
This is the difference between measured cations and measured anions
Anion gap
What is the equation for anion gap
Na- (HCO3 +Cl)
What is the range for anion gap
8-16 meq/L
When is the anion gap used
-The differential diagnosis of metabolic acidosis
What causes an increased anion gap
MUDPILES
What causes a normal anion gap
Loss of base (diarrhea)
