Exam III: Acid Base Balance Flashcards
What is the lowest pH a patient can survive with?
6.8
What is the highest pH a patient can survive with?
7.8
Life depends on maintaining what 3 things?
- The proper amt. of body water
- The correct proportion of water and electrolytes in the water
- the body pH within a narrow range
_____ affects the structure of proteins, and consequently, the function of enzymes, receptors, transport P, channels, etc.
H ions
Substances in the body that are important to maintain the pH of 7.4
Buffer
What are the 2 buffer systems?
- intracellular
2. extracellular
What two organs help maintain the physiological pH?
lungs and kidney
What is eliminated from the lungs to help maintain pH
CO2
What is eliminated from the kidneys to adjust pH?
H+ and HCO3-
If you inc. H+ you will inc/dec pH?
Dec.
solutions with a lower pH will have a high/low H conc.?
high
Solutions with a high pH will have a high/low pH conc?
low
A solution with the same pH as water (pH 7)
neutral
What is the logaritmic expression of pH?
pH=
-log(H+)
Which of the following has the highest pH?
a. gastric juice
b. plasma
c. pancreatic juice
c. pancreatic juice
Which of the following has the lowest pH?
a. gastric juice
b. plasma
c. pancreatic juice
a. gastric juice
Whicch of the following has the highest H+ conc?
a. gastric juice
b. plasma
c. pancreatic juice
a. gastric juice
What equation do we use to cal culate pH in living organisms?
Henderson-Hasselbalch equation
what values are used to calculate the henderso- H equation?
CO2
Bicarbonate
If you have an inc. in HC03 you will have a inc/dec in pH
inc
If you have an inc. in PC02 you will have an inc/dec in pH
dec.
what is alkalosis?
inc in pH
What is acidosis
Dec in pH
molecule that can release H+ ions
Acid
what are the 2 types of acids?
- Volatile acids
2. Non-volatile acids
Where do volatile acids come from?
combination of CO2 with H2O
Where do non-volatile acids come from?
byproducts of metabolism
Molecule that can accept H+
base
An acid that rapidly dissociates and releases high amounts of H+
strong acid
An acid that releases H with less vigor
weak acid
A base that reacts rapidly and strongly with H and removes H very quickly from solution
Strong Base
Which of the following substances are considered buffers?
a. carbohydrates
b. bicarbonate
c. hemoglobin
d. fatty acids
e. b and c
f. all of the above
e. B and c
A base that reacts slowly to H+
Weak base
What is the most important acid in the ECF.
H2CO3
What is the most important base in the ECF?
HCO3-
Are the acids and bases found in the ECF strong or weak?
Weak
A molecule formed by the combination of one or more of the alkaline metals with a basic ion
Alkali
Are acids or bases alkali?
Base
A substance that is able to neutralize small amounts of added acid or base, thus maintaining the pH of the solution relatively stable?
Buffer
What is the dissociation constant (pK)?
pH at which half of the aid is dissociated and half is undissociated
T/F. intracellular pH is slightly higher than plasma pH?
F. slightly lower
T/F. Cells under ischemia show a more acidic pH than cells under normal conditions?
T
A depression of pH below the normal range?
Acidemia
An elevation of pH above the normal range?
Alkalemia
A disturbance caused by the addition of excess acid or removal of base from the ECF
Acidosis
A disturbance caused by the additon of excess base or the removal of acid from the ECF?
Alkalosis
What are the 3 systems that regulate H+ and HCO3- conc. and the pH in the body?
- buffer systems
- respiration
- kidneys
Which of the 3 pH regulating systems acts the quickest?
buffer systems
What are the 3 components of the buffer system?
- bicarbonate
- phosphate
- proteins
How does respiration work to regulate pH?
regulates CO2
How do the kidneys work to regulate pH?
excrete and reabsorb H+ and HCO3-
Which blood constituent can be used to indirectly calculate the concentration of HCO3-?
a. ocygen
b. CO2
c. HCO3-
d. H2O
CO2
In tissue hypoxia or ischemia, what pH would you expect?
a. more acidic
b. more alkaline
c. no change
a. more acidic
T/F. A buffer is a substance that can bind H+ irreversibly.
F. Reversibly
What is the most important extracellular buffer system?
bicarbonate buffer
How is HCO3 regulated i the hydration reaction?
the kidneys
How is CO2 regulated in the hydration reaction?
lungs
What is the pK of the bicarbonate buffer system?
6.1
If there is an excess in H+ which way will the hydration reaction shift? To the right or left?
Left. Excess CO2 will be eliminated.
If there is a dec. in conc. of H+ which way will the hydration reaction shift? right or left?
Right. Respairation is inhibited to conserve CO2
Which buffer system is important in intracellular fluid and renal tubule fluid?
Phosphate buffer system
What does the phosphate buffer system respond to?
high conc. of phosphate in the tubular lumen
What is the pK of the phosphate buffer system?
6.8
Which buffer system in our body is considered open? and why?
bicarbonate buffer system, because lungs and kidneys can alter conc. of CO2 and HCO3-
How do proteins act as buffers?
basic amino acid groups can accept protons
What is the important buffer system in erythrocytes?
Hb
What are the two positions that Hb can accomodate protons?
- Histidine’s side chain
2. Carboxyl groups
What are the 3 intracellular buffers?
- amino acids
- proteins
- phosphate
in reference to membrane carriers, what would happen if pH in the cytosol dec?
Na/H+ exchanger will be activated
Cl/HCO3 exchanger will be inhibited
If you have an inc. in ventilation, you will have an inc. in CO2 and a ____ in H+
dec.
If you have a dec. in ventilation, you will have a dec. in CO2 and a ____ in H+
inc.
HCO3- can be absorbed in all parts of the nephron except:
thin limb of the loop of henle
T/F Bicarbonate is freely filteralbe.
T
In acidosis, ______ will be reabsorbed.
HCO3-
In alkalosis, ______ will be excreted
HCO3-
In Acidosis, ______ will be excreted
Excess H+
type A intercallated cells secrete_____ and reabsorb _____.
Acid (h+), HCO3-
type B intercalated cells reabsorb _____ and eliminate _______
H+, HCO3-
A Dec. conc. of K ions in the ECF
Hypokalemia
What is the effect of Hypokalemia
muscle weakness because of dec. neural transmission
A cow presents K deficiency on the blood (hypokalemia) caused by malnutrition. which of the following would you expect? (two answers)
a. The urine becomes more acidic
b. The blood pH becomes more acidic
c. The urine pH becomes more alkaline
d. The blood’s pH becomes more alkaline
a and d
K intracellular conc.
140 mmol/L
K extracellular conc.
5mmol/L
What is the effect of hyperkalemeia?
cardiac toxicity
In hyperkalemia, you will have an inc/dec in pH
dec.
in hypokalemia, you will have an inc/dec in pH
inc.
In acidosis, ____ leaves the cell, and ____ enters
H, K Apically
in alkalosis, ___ leaves the cell and ___ enters
H, K Basolaterally
If you have a metabolic acidosis or alkalosis which organs will compensate?
lungs
the most important buffers in the blood are:
a. bicarbonate and phosphate
b. phosphate and protein
c. bicarbonate and Hb
d. bicarbonate and protein
c.
If you have respiratory acidosis/alkalosis which organs will compensate?
renal
T/F.a poor kidney function would inc. H+ conc. and stimulate ventilation.
T
What 4 parameters are needed for analyzing acid-base status?
- pH
- pCO2
- standard bicarbonate
- base excess
Way to evaluate acid-base disorders that uses electrolytes.
Anion gap
What is the law of electroneutrality?
the concentration of anions and cations in plasma must be equal
the difference between unmeasured cations and unmeasured anions
anion gap
the renal tubules affects acid base balance by: a. generating new HCO3- b. eliminating H+ as ammonium c. Altering the pK of the HCO3 Buffer d. Eliminating CO2 e. Both a and b F All of the above
e
Transmembrand H+ transport in the PT is accomplished by
a. an antiport with Na
b. A H+ ATPase
c. H+/K+ exchanger
d. A and B
e. All of the above
d.
Movement of cows to high altitude pastures during summer can cause:
a. an inc. hematocrit
b. an alkalosis
c. hypercapnia
d. hypoventilation
e. a and b are right
f. b and c are right
e.
What 4 disorders may cause respiratory alkalosis?
- alveolar hypervent. during anesthesia
- High altitude
- damage to resp. center
- emotional excitment
What are 5 disorders that may cause metabolic acidosis?
- Renal failure
- hyperkalemia
- hyperparathyroidism
- diarrhea
- fistulas
What are 5 disorders that cause metabolic alkalosis?
- vomiting
- torsion of the abomasum
- hypokalemia
- hypoparathyroidism
What are 4 disorders that cause respiratory acidosis?
- Alveolar hypoventilation
- fractured ribs
- bloated abdomen
- resp. obstructive disease
a metabolic acidosis cannot be caused by
a. diarrhea
b. diabetes mellitus
c. renal failure
d. torsion of the abomasum in ruminants
d.