Buffers Flashcards
buffer
Chemicals in body that combine with acid or base to change the pH
Excepts or releases H+
bicarbonate
Main extracellular buffer
CO2 byproduct of all cellular metabolism
Combines with water to form carbonic acid
what chemical breaks carbonic acid down
Carbonic anhydrase
phosphate buffer
Intracellular buffer
Protein buffers
carboxyl group
Amino group
Hemoglobin group
Carboxyl group
includes amino acid and acetic acid
Weak acid that gives up H+
Amino group
amino acid, ammonia
Accepts H+
Hemoglobin group
Picks up CO2 at cellular level
Effects of increased hydrogen ion concentration
decrease pH – more acidic
H + moves into cell
More positive charged ions in cell
K+ moves out of cell
Electrical neutrality
T/F if kidneys are working they will excrete access K+
True
respiratory mechanisms
Exhalation excretes carbonic acid
PH can be adjusted by changing the rate and depth of breathing
do respiratory mechanisms affect lactic acid?
No, it doesn’t affect non-volatile acids
kidney excretion
Can eliminate large amounts of acid, except for carbonic acid
Can excrete base
Can conserve and produce bicarbonate ions
what is the most effective regulator of pH?
Kidney excretion
if kidneys fail, does the pH balance fail?
Yes
buffer rate of correction
Instantaneous
respiratory mechanism rate of correction
Minutes to hours
Quickest
Renal mechanism rate of correction
hours to days
Longer lasting
acidosis pH
<7.35
alkalosis pH
> 7.45
what occurs if the underlying problem is metabolic?
Respiratory compensation
Hypoventilation
Hyperventilation
what occurs if the problem is respiratory?
Metabolic compensation
what triggers the lungs to increase, or decrease rate, and depth of breathing to adjust the pH?
Excess CO2
relationship for hyperventilation
CO2 blown off
Increased pH
relationship for hypoventilation
CO2 retained
Decreased pH
what occurs with renal control of pH?
Amount of bicarb is adjusted by being re-absorbed into the bloodstream or excreted in urine
if the blood is too acidic –
Kidneys reabsorb bicarbonate
if blood is too alkalotic –
Kidneys excrete bicarbonate
normals of ABG
PH 7.35-7.45
CO2 35-45
pO2 80-100
HCO3 22-26
O2 sat 95-100