Acid Base Physiology - Exam 3 Flashcards
what is an acid
proton donor (contributes)
what is a base
proton acceptor (binds, buffers)
in Latin H+ actually means
hydrogen power
strong acid/base properties
readily dissociate, always more ionized than not, pKa doesn’t apply
weak acid/base properties
do not readily dissociate, use pKa
buffer systems exist to maintain
homeostatic plasma pH 7.34-7.45 either bicarbonate or non-bicarbonate
open system characteristics
more powerful than closed (since they’re saturable), can eliminate acid from the body
bicarbonate - carbonic acid buffer system
most abundant & most important, H2CO3, pKa 6.1, CO2 & H2O also always present
ubiquitous equation
CO2 + H2O -> H2CO3 -> HCO3- + H+
bicarbonate - carbonic acid buffer system: LUNG
CO2 handling, changes in ventilation (body’s ability to expel CO2), increase exhalation with lower pH, fast response
bicarbonate - carbonic acid buffer system: KIDNEY
bicarbonate HCO3- handling, secretion/excretion/reabsorption, long response
non-bicarbonate buffer systems
proteins, phosphates, ammonia
ICF buffer system
phosphate & protein mostly (because of hemoglobin), then carbonic acid
interstitium buffer system
carbonic acid, protein, phosphate
CSF buffer system
carbonic acid
