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48 Cards in this Set
- Front
- Back
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What is the intracellular pH range?
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7.0-7.1
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What is the extracellular pH range?
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7.35-7.45
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What is acidosis?
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pH < 7.35
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What is alkalosis?
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pH > 7.45
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What happens with pH with hyperventilation?
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carbon dioxide decreases => alkalosis
because bacarbonate/carbonic acid is >20:1 |
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What happens with pH with hypoventilation?
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carbon dioxide increase => acidosis
because bicarbonaate/carbonic acid ratio is < 20:1 |
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What are the three regulators of pH
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1. chemical buffer systems
2. respiatory mechanism 3. renal mechanism |
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chemical buffer systems
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1st to respond
takes < 1 sec temporarily "tie up"excess acids and bases carbonic acid- bicarbonate; phosphate;protein buffer systems |
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respiratory mechanism
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2nd to respond
takes 1-3 minutes respiratory center inolved removes CO2 and therefore H2CO3 |
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renal mechanism
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3rd to resond but most potent!
takes hours to days kidneys remove metabolic acids (Pi, uric and lacitc acids, ketone bodies) |
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What is the function of a chemical buffer?
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resist sudden changes in pH
temporarily help prevent body fluids from being too acidic or too basic |
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What are th general components of a chmical buffer?
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a weak acid and its salt
OR a weak base and its salt |
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acid
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tends to donate a proton
HA <->H+ + A- |
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base
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tends to accept a proton
B + H+ <-> BH+ |
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pH realted to H+=
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-log[H+]
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pH related to pKa=
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pH=pKa+ log ([A-]/[HA])
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Ka=
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[H+][A-]/[HA]
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What is the most important one in the ECF?
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carbonic aicd-bicarbonate buffer system
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What is the enzyme of the carbonic acid-bicarbonate buffer system?
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carbonic anhydrase
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the carbonic acid-bicarbonate buffer rxn is _____.
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reversible
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carbonic acid is a weak acid with a pKa of what?
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6.1
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what is the major buffer in the plasma ?
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carbonic acid
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the pH of blood can be determined using what equation?
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Henderson-Hasselbalch
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What is the solubility constant of carbon dioxide?
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0.03
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What does the plasma pH equal when the buffer ratio is 20/1
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7.4
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plasma pH may be affect by a change by two factors..which are?
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bicarbonate concentration
PCO2 |
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What buffer system is important in ICF and urine?
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the phosphate buffer system
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at physiological pH, the phsophate buffer system is in what form?
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proton-acceptor form
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what is the pKa of the phosphate buffer system?
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6.8
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What buffer system is important in ECF and ICF AND interacts with other buffer systems?
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protein buffer systems
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What are three types of protein buffer systems?
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hemoglobin buffer system (RBCs only)
amino aicd buffers (all proteins) plasma protein buffers |
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What is the pKa range for protein buffers?
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5.5-8.5
slower than other chemcial buffers remove either excess H+ or excess OH- depending on pH |
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DeoyxHb is a ___ acid than oxyHb
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weaker
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acidemic
alkalemic |
pH<7.35
pH>7.45 separate terms for pH to allow description of the net effect of multiple respiratory and metabolic abnormalities |
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What are the four primary disorders
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respiratory acidemia
respiratory alkalemia metabolic alkalemia metabolic acidemia |
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What expresses the relationship between plasma pH, concentration of bicarbonate, and partial pressure of carbon dioxide?
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Davenport
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respiratory acidosis
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PCO2 is raised
pH is reduced HCO3 is normal |
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compensated respiratory acidosis
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PCO2 still raised
HCO3- raised pH is now normalized |
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respiratory alkalosis
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PCO2 is reduced
pH is raised HCO3 is normal |
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compensated repiratory alkalosis
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PCO2 is still reduced
HCO3 is lowered pH is normalized |
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metabolic acidosis
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PCO2 is unchanged
pH is reduced HCO3 is reduced |
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compensated metabolic acidosis
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PCO2 lowered
pH is normalized HCO3 is still reduced |
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metabolic alkalosis
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PCO2 is unchanged
HCO3 is increased pH is increased |
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compensated metabolic alkalosis
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HCO3 is still increased
PCO2 is now raised pH is normalized |
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What's an example of metabolic alkalosis?
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net loss of H+ through vomiting, ingestion of soda (NaHCO3)
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What are examples of metabolic acidosis?
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diabetes, renal failure, heart failure, diarrhea
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What are examples of respiratory alkalosis?
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hyperventilation on anxiety and hysteria
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What is an example of repiratory acidosis?
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retention of CO2 generally caused by respiratory problems
hypoventilation asthma: chest tightness, cough, wheeze |
