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78 Cards in this Set
- Front
- Back
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What is pH ?
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The measure of the strength of acids & bases
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What is pH defined as?
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the negative logarythm of the conc. of H+ ions in 1 mol H2O
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Mols always equal the same # of _______.
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Ions
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What is the basic pH of urine?
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4.6 to 8.0
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What is the pH of most body fluids?
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7.4
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What are acids?
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proton donors
H2CO3--H+ + HCO3- |
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What are bases?
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proton acceptors
H+ + HCO3- ----- H2CO3 |
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A _____ acid ionizes almost completely in solution.
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strong
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What type of acid has a weak conjugate base & requires a high H+ concentration to accept a proton & form the undissociated acid.
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strong acid
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_______ acids dissociates completely in solution, attacking in all directions
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strong acids
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______ ionizes only partly in solution
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weak acids
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_______ acid has a strong conjugate base & a high binding force to H+.
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weak acid
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________ consists of a weak acid plus its strong base
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buffer system
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The _____ is the particular pH at which a buffer is dissociated to 50%
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pK
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What are the two factors that can determine a buffer capacity?
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1) the pK
2) the concentration of the buffer |
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What is pH ?
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The measure of the strength of acids & bases
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What is pH defined as?
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the negative logarythm of the conc. of H+ ions in 1 mol H2O
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Mols always equal the same # of _______.
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Ions
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What is the basic pH of urine?
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4.6 to 8.0
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What is the pH of most body fluids?
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7.4
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What are acids?
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proton donors
H2CO3--H+ + HCO3- |
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What are bases?
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proton acceptors
H+ + HCO3- ----- H2CO3 |
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A _____ acid ionizes almost completely in solution.
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strong
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What type of acid has a weak conjugate base & requires a high H+ concentration to accept a proton & form the undissociated acid.
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strong acid
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_______ acids dissociates completely in solution, attacking in all directions
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strong acids
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______ ionizes only partly in solution
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weak acids
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_______ acid has a strong conjugate base & a high binding force to H+.
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weak acid
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________ consists of a weak acid plus its strong base
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buffer system
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The _____ is the particular pH at which a buffer is dissociated to 50%
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pK
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What are the two factors that can determine a buffer capacity?
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1) the pK
2) the concentration of the buffer |
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What type of buffer covers the biological pH of 7.4?
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phosphate
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What is a phosphate buffer useful & not useful for?
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It sits @ physiological pH centers & is useful in the cell but not very useful in blood.
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Why are phosphate buffers not important in blood & ECF?
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Very low concentration in blood plasma & ECF
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What is the advantage of a pH buffer?
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close to the physiological pH values, pK= 6.8
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______ buffer is useful in both ICF & blood.
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protein
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What is the pK found in proteins?
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close to 7.4
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______ is an important intracellular buffer in all cells.
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protein buffer
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What is the important role of a bicarbonate buffer?
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To maintain a constant blood pH.
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Since H2CO3 is formed from a gas it is called a ______ acid.
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volatile
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What is meant by an open buffer system?
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It is when CO2, H2CO3 & HCO3- vary due to changes in the metabolism & excretion, increasing buffer capacity.
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At a pH of _____ there is 20 times more ____ than _____ & therefore the buffering is better against excess acid than excess base.
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7.4
base than acid |
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The pH in blood & ECF is maintained at a constant level by _____, _____ & _____.
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buffers, respiration, & renal excretion
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Metabolic acids come from ________.
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endogenous protein
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Carbonic acid come from _________.
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respiration
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Any condition in which arterial blood pH falls below pH 7.36 is called ______.
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acidosis
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Any condition in which arterial blood pH rises above pH 7.44 is called ______.
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alkalosis
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respiratory acidosis disorder is compensated by _________
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metabolic alkalosis
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respiratory alkalosis disorder is compensated by _________
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metabolic acidosis
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metabolic alkalosis disorder is compensated by _________
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respiratory acidosis (hypoventilation)
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metabolic acidosis disorder is compensated by _________
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respiratory alkalosis
(hyperventilation) |
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What are the 3 lines of defense against changes in [H+]?
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Buffers
respiratory system renal system |
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Why are buffers the first line of defense against changes in [H+]?
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Its an immediate reaction to acid/base disturbance but the weakest, capacity is limited & are saturated quickly.
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Why is the respiratory system the 2nd line of defense against changes in [H+]?
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By increasing/decreasing CO2 elimination to help limit the extent of the disturbance & pH will not return to normal.
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Why is the renal system the 3rd line of defense against changes in [H+]?
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This the most powerful line of defense & may take days to activate. They compensate excess acid/base by increasing/decreasing the excretion of H+ or HCO3-.
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What is the respiratory acid-base disorder that causes the increased alveolar production of CO2?
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respiratory acidosis
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What is the respiratory acid-base disorder that causes the decreased alveolar production of CO2?
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respiratory alkalosis
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What are some causes of respiratory acidosis?
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lung disease
weakness of respiratory muscles CNS disease drug overdose |
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What are some causes of respiratory alkalosis?
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voluntary overbreathing
artificial ventilation drug overdose |
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What respiratory acid-base disorder causes a decrease in alveolar CO2 production?
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respiratory alkalosis
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When H+ production exceeds excretory capacity, what acid-base disorder would occur?
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metabolic acidosis
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When H+ excretion failure occurs, what acid-base disorder would occur?
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metabolic acidosis
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When there is excess loss of HCO3- from the body, what acid-base disorder would occur?
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metabolic acidosis
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What are some examples of disorders that are caused when H+ production exceed excretory capacity?
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*disorder of metabolism (starvation,ketosis,diabetic ketoacidosis,lactic acidosis)
*ingestion of substances that give rise to H+. |
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What is an example of a disorder that is caused by H+ excretion failure?
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Inadequate production of NH3 by kidney (chronic renal failure)
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What are some examples of where a loss of HCO3- from the body would occur causing metabolic acidosis?
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*from gastrointestinal tract (severe diarrhea)
* in urine (carbonic anhydrase inhibitors & proximal renal tubular acidosis) |
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A loss of H+ from the body or an addition of base that exceeds the amount excreted are examples of what acid/base disorder?
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metabolic alkalosis
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What are 4 examples of disorders that are caused by a loss of H+ from the body?
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vomiting
diuretics (thiacides) glucocorticoid excess mineralocorticoid excess severe K+ depletion |
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What is an example of a disorder that is caused by an addition of base in the body that exceeds excretion?
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Ingestion of alkali (NaHCO3- gastric ulcer)
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What is an oral treatment for acidosis?
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sodium bicarbonate
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What are 2 I.V treatments for acidosis?
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sodium lactate
sodium gluconate |
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What is an oral treatment for alkalosis?
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ammonium chloride
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What is an I.V treatment for alkalosis?
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lysine hydrochloride
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What is a buffer base status in acid-base disorders?
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It is the sum of all conjugate bases in 1 L of arterial whole blood.
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What does an anion gap show?
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It shows the difference bt. concentrations of anions & cations
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An increase in metabolic acidosis & a decrease in most cases of metabolic alkalosis is an example of what acid/base evaluation status?
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anion gap
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What does Base Excess (BE) show?
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It shows deviations from normal values.
[BE]= observed [BB]- normal[BB] |
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What is a negative deviation?
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It is termed a Base Deficit (acid excess) & relates to an acidosis.
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What is a positive deviation?
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It is termed base excess & relates to an alkalosis.
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