Cell bio- acid-base balance Flashcards

1
Q

metabolic processes in the body result in the production of what?

A

large amounts of acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Where are acids produced by the metabolisms transported to, how are they transported and how it it accomplished?

A

transported to the lungs and kidneys
via ECF and blood without changing plasma pH
accomplished by the buffering capacity of blood and respiration and renal regulatory mechanisms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

define acid

A

proton donor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

define base

A

proton acceptor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

define strong acid and weak acid, and what are examples?

A

strong dissociates very quickly in solution and release large amount of H (HCl, HNO3, H2SO4)
weak partially dissociate in aq sol (H2CO3)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

define strong base and weak base and what are examples?

A

strong reacts vey quickly with H, removing it from sol (OH)

weak doesn’t fully ionize in an aq sol (HCO3)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is the concept of acidity?

A

in aq sol, protons are normally bound by electrostatic interaction to H2O= H3O

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what does the acidity of a solution refer to?

A

the chemical activity of its constituent H ions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is the concentration of H ions compared to electrolytes in body fluids?

A

a million times less

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

why must [H] of body fluids be kept constant, and what can it affect?

A

they are highly reactive

affects enzyme function and cellular structure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What equation defines pH?

A

-log10[H]

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what does [H] determine?

A

the pH of the body fluids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is the normal extracellular fluid [H] and what is the pH of blood?

A

40 nEq/L

7.4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

define pH

A

a numeric scale used to specify the acidity or basicity of an aq sol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is the relationship between pH and [H]?

A

inverse relationship

the greater the H, the lower the pH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

define acidemia

A

decrease in ECF pH below normal limits, [H] increases above normal limits

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

define acidosis

A

the pathophysiologic processes that cause net accumulation of acid in the body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

define alkalemia

A

the increase in ECF pH above normal limits, [H] is below normal limits

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

define alkalosis

A

the pathophysologic processes that cause net accumulation of alkali in the body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

t/f: an animal can have alkalosis without alkalemia?

A

true

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what is the graphical relationship between pH and [H], a change in one pH unit changes [H] by what?

A

they vary exponentially of one another

factor of ten

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what is the law of mass action?

A

the velocity of a reaction is proportional to the product of concentrations of the reactants

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what three things does the law of mass action describe?

A
  1. explains and predicts behavior of solutions in dynamic equilibrium
  2. for the acid, there are two opposing reations (HA -> H+ A & H+A -> HA)
  3. the velocity of the 1st and 2nr rxns (v1=k1[HA] & v2=k2[H][A])
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what does the law of mass action describe at equilibrium?

A

the rates of the two opposing reactions counterbalance one another and the two velocities are equal
k1[HA]=k2[H][A]

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
what is Ka?
dissociation constant | the concentration of the acid relative to its dissociated ions
26
what are two equations that equal Ka?
k1/k2 | [H][A]/[HA]
27
what is the equation for law of mass action when the concept if pH is applied to the H and Ka?
pH= pKa + log ([A]/[HA])
28
what is the henderson-hasselbalch equation used to calculate, and what is the equation?
the pH of a solution based on the base and acid concentrations pH=pKa + log(base/acid)
29
define buffer
a compound that can accept of donate protons and minimize a change in pH when an acid or base is added
30
what does a buffer solution consist of? (2)
a weak acid and its conjugate base
31
what is considered the first line of defense to prevent major changes in pH?
blood buffers
32
what is the isohydric principle, and what does it allow?
multiple buffers in the same solution are always in equilibrium if one system is known, changes in other systems can be predicted
33
how the the ionic composition of fluids maintained and why?
within marrow limits important for optimal functioning of the cells serious deviations of pH disrupt cell metabolism
34
what are the 3 systems that help regulate [H] and pH in body fluids and what is their function?
chemical buffer systems (manage the imbalance) lungs & kidneys (try to correct the pH by adjustments in ventilation or changes in renal function)- bicarbonate buffer system and phosphate buffer system
35
how to blood buffers act as the first life of defense to prevent major changes in pH?
thay don;t add or remove H, but keep them in control until the balance is restored
36
what are the 2 proteins used in a buffer system?
hemoglobin | plasma protein
37
what are proteins used as buffers for?
intracellular acid-base balance
38
why to RBC have a significant and rapid impact on ECF?
hemoglobin H and HCO3 move slowly across other protein membranes, causing a delay for the max ability of intracelluar proteins to buffer extracellular acid-base abnormalities
39
what do proteins have that allow them to be buffers and what are two examples?
a large number of acidic and basic groups imidazole ring of histidine residues amino-terminal groups
40
what do proteins couple with to contribute to the total body acid-base balance?
phosphate buffer
41
what is the most important blood buffer and what system is it with?
hemoglobin | bicarbonate buffer system
42
what are the two mechanisms by which H bind to hemoglobin?
via basic carboxym groups (RCOOH) | via imidazole groups of histidine (bond with ion of the heme group)
43
what molecule is continuously formed by the intracellular metabolism and what are three forms that it is transported in the blood as?
CO2 | dissolved CO2, carbonic acid, bicarbonate ions
44
what buffer system is the most important of the ECF, what does it consist of (2), how are its components regulated and by what organs?
Bicarbonate buffer system weat acid (carbonic acid) and conjugate base (bicarbonate ion) independently regulated= open system CO2 by lungs and bicarbonate by kidneys
45
how is carbonic acid and bicarbonate formed? are their reactions reversible or irreversible and what is it called?
carbonic acid= reaction between CO2 and H20 bicarbonate= dissociation of H2CO3 in H + HCO3 reversible reaction hydration reaction
46
what enzyme catalyzes the hydration reaction and where is it abundant (3)?
carbonic anhydrase within RBC in walls of the lung alveoli in epithelial cells of the renal tubules
47
what is the concentration of phosphates compared to bicarbonate buffer?
low concentration
48
where are phosphates used as buffers (2) and what is it made up of?
``` intracellular and tubular filtrate of the kidneys weak acid (monosodium phosphate) and conjugate base (disodium phosphate) ```
49
what is formed when phosphates react with a strong acid/base?
strong acid: a weaker acid and a salt | strong base: a weaker base and water
50
what is the second line of defense to acid-base balance and how quickly does it occur?
respiratory system | acts within minutes
51
what is the capacity to buffer in the respiratory system compared to the chemical buffer system and what is the role of lungs?
twice the capacity | lungs control the [CO2] in the ECF
52
what is the effect of pH on alveolar ventilation and how does the respiratory system respond to an abnormal pH?
ventilation inc 4-5 times when pH dec to 7.0 ventilation dec when pH is over 7.4 respiratory system tries to compensate an abnormal pH
53
How do Pco2, H and Po2 affect alveolar ventilation?
inc Pco2 & H, dec Po2 = inc ventilation | dec Pco2 & H, inc Po2= dec ventilation
54
what is the effect of alveolar ventilation on pH and what can be the primary cause for an abnormal blood pH?
a double inc in ventilation inc ECF pH to 7.63 a 1/4 dec in ventilation dec ECF pH to 6.95 respiratory disease
55
what is the third line of defense for acid-base balance, how does it compare to the other regulators and how quickly does it respond?
kidneys most powerful regulator hours to days
56
how do the kidneys act to balance pH and how does it achieve real loss of base or acid?
act through the excretion of basic or acid urine HCO3 is continuously filtered to the tubules and new ones are formed, high amounts of H are secreted in the tubular lumen and excreted with other buffers (phosphate and ammonium) real loss= changes in the amount of HCO3 filtered or H secreted
57
what is the role of the kidneys, how does it perform its role and where?
regulate the [H] in ECF secretion of H (85% proximal tubules, 10% distal tubules, 5% collecting ducts) reabsorption of filtered HCO3 production of new HCO3
58
what two organs keep pH within tolerable limits and when are these mechanisms inadequate?
lungs & kidneys | severe disease
59
what are 4 possible primary acid-base disturbances?
metabolic acidosis & alkalosis | respiratory acidosis & alkalosis
60
define acidosis
the pathophysiological processes that result in an abnormal low pH
61
define alkalosis
the pathophysological processes that result in an abnormal high pH
62
what is the pH range for arterial blood and what may the values vary based on (3)?
7.35-7.45 | vary depending on sea level, lab and assay
63
what are the metabolic and respiratory components?
``` metabolic= HCO3 respiratory= Pco2 ```
64
what are the three causes of metabolic acidosis?
gain of acids loss of bicarbonate compensatory mechanism for respiratory alkalosis
65
what are 4 methods of gain of acids causing metabolic acidosis?
ketones (beta-hydroxybutrate) lactate (hypoperfusion) intoxication with exogenous compounds (ethylene glycol, aspirin) renal failure (build up of phophates and sulfates)
66
what are 3 methods of loss of bicarbonate causing metabolic acidosis?
``` renal tubular acidosis diarrhea rumen acidosis (large animals) ```
67
what are 3 causes of metabolic alkalosis?
excessive elimination of hydrogen intake of a base compensatory mechanism for respiratory acidosis
68
what are 4 methods of excessive elimination of hydrogen causing metabolic alkalosis?
``` persistent vomiting (loss of HCl) hypokalemia (tenal tubule cells secrete inappropriate amounts of H into urine) torsion and dilation of abomasum (ruminants) ```
69
what are 2 methods for intake of a base causing metabolic alkalosis?
injection of bicarbonate solution | ingestion or injection
70
when does respiratory acidosis occur and what are 3 causes?
when the CO2 production exceeds the CO2 loss by the lungs depression of respiratory centers in the central nervous system abnormality of the chest wall or respiratory muscles obstructions to gas movement or diffusion within the lungs compensatory mechanism for metabolic alkalosis
71
what is an example of depression of respiratory centers in the CNS causing respiratory acidosis?
analgesic/anesthetic drugs
72
what are 2 examples of abnormality of the chest wall of respiratory muscles causing respiratory acidosis
cervical lesions | neuromuscular disorders
73
what are 3 examples of obstructions to gas movement of diffusion within the lung causing respiratory acidosis?
decreased alveolar ventilation impediment of diffusion between alveoli and capillary blood primary pulmonary diseases
74
when does respiratory alkalosis occur and what are 2 causes?
when the loss of CO2 exceeds the rate of production hyperventilation compensatory mechanism for metabolic acidosis
75
what are 3 examples that cause hyperventilation, which causes respiratory alkalosis?
any cause of hypoxemia | congestive heart failure, hypotension, anemia