Patho Acid-Base

dissociate

separation of a molecule into 2 or more simpler fragments (NaCl → Na+ and Cl-)

carbonic anhydrase (CA)

• enzyme found in RBC and renal tubular cells

• responsible for rapid conversion of CO2 and H20 into carbonic acid

• helps carbonic acid dissociate into CO2 and H20

• makes CO2 dissolve in water rapidly

carbonic acid

CO2 dissolved in water (H2CO3)

bicarbonate

primary base in body (HCO3-)

acids

• molecules that release H+ ions in solution

• volatile

• non-volatile

volatile acids

• easily vaporized or evaporated

• can be eliminated by lungs

• CO2, H2CO3

non volatile acids

• fixed acids that can be eliminated by kidneys after being buffered

• occurs from metabolism of dietary proteins, CHO, and fats

carbonic acid concentration is determined by

the lungs & their ability to exhale

bases

• ions or molecules that can accept a H+

• HCO3- = primary base buffer

sources of bases

• metabolism of amino acids

• metabolism of organic anions

3 ways pH is regulated

• chemical buffering

• respiratory response

• renal response

pH regulation: chemical buffering

• occurring in response to changes in acid-base status

• buffers absorb excessive acids or bases

• chemical buffer systems occur in body fluids

• responsible for preventing wide ranges of acidity or alkalosis

• immediately combine with acids or bases to prevent large pH changes

pH regulation: respiratory

• lungs control CO2 elimination

• rid volatile acids from body

• will travel to lungs ad dissolved CO2, H2CO3, or HGB

pH regulation: kidneys

• longer time, more effective

• rids non-volatile acids from body

• eliminates H+

• reabsorbs HCO3-

• generated HCO3-

bicarbonate buffer system

• main buffer system in body

• uses H2CO3 and bicarbonate salt (NaHCO3)

• substitutes weak acid for strong acid OR weak base for strong base

  • allows for easier addition or removal from body

transcellular buffer system

• H and K move freely between compartments making this exchange work between ICF & ECF

• since H and K are both + ions, they can exchange as needed

bone buffer system

• excess H ions exchanged for Na and K on bone surface → dissolution of bone minerals

• release of NaHCO3 and CaCO3 into ECF to buffer acids

correction mechanism when body is acidotic

• RBC can release CA in lungs & generate carbonic ion that can be