acid base and pH regulation Flashcards
(65 cards)
1
Q
what is the normal level of plasma pH
A
7.4
2
Q
what does acid base balance affect
A
- enzyme function
- cellular function
- CNS and CVS function
- oxygen transport
- electrolyte balance
- acid waste elimination
3
Q
how is enzyme function affected by acid base
A
- catalyst for biochemical
- pH changes denatures and dysfunction hindering metabolism
4
Q
how is cellular function affected by acid base
A
- needed for cell integrity and function
- have pH dependent transport mechanisms
- ph change hinder cell function and cause death
5
Q
how is CNS and CVS function affected by acid base
A
- influences contractility of heart and response of blood vessels
- acidosis and alkalosis cause neuronal dysfunction
6
Q
how is oxygen transport affected by acid base
A
- affect haemoglobin affinity
- alters O2 carrying capacity
7
Q
how is electrolyte balance affected by acid base
A
- affects regulation of electrolytes
- concentration needed for nerve conduction, muscle function and fluid balance
8
Q
how is acid waste elimination affected by acid base
A
- metabolism produces acid waste
- elimination through lungs and kidneys prevents accumulation
9
Q
what is pH
A
measure of how basic or acidic a solution is
10
Q
what is acid
A
substance that donates protons
11
Q
what is a base
A
substance that accepts protons
12
Q
what is a buffer
A
solution which reduces the affect of adding or removing H+
13
Q
what is HCO3-
A
bicarbonate acts as a base accepts excess H+ to regulate pH
14
Q
what does the henderson-hasselbalch equation consider
A
- changing concentration of CO2 or HCO3 alters the pH
- increase arterial PCO2 drops arterial pH
15
Q
what is the henderson -hasselbalch equation
A
pH = 6.1+ log [HCO3}/o.o3 x PCO2
16
Q
how do changes in CO2, H+ and HCO3 affect each other
A
^ CO2 + H2O <-> H2CO3 <-> HCO3 + ^ H+
17
Q
affect of decreased PaCO2
A
increases pH
18
Q
affects of increase PaCo2
A
decreased pH
19
Q
affects of increase HCO3
A
increased pH
20
Q
affects of decreased HCO3
A
decrease pH
21
Q
what is acidosis
A
increase of hydrogen ions and a reduction of bicarbonate
22
Q
what is alkalosis
A
decrease in hydrogen ion and increase of bicarbonate
23
Q
what is respiratory acidosis
A
- CO2 retention from hypoventilation
- increasing H+
24
Q
what are causes of respiratory acidosis
A
resp conditions with CO2 retention
25
what is metabolic acidosis
all types of acidosis from excess CO2 in body fluids
26
what causes metabolic acidosis
- increase acid production
- loss of bicarbonate
- decrease acid excretion
27
what is respiratory alkalosis
excessive CO2 lost from the body from hyperventilation
28
what causes respiratory alkalosis
- hypoxia
- hyperventilation
29
what is metabolic alkalosis
reduction in plasma caused by relative deficiency in no carbonic acids
30
what causes metabolic alkalosis
- hydrogen loss
- excess HCO3 ingestion
31
what are the differentiation values for acidosis
- metabolic = HCO3 <24
- respiratory = PaCO2 >6
32
what are the differential values for alkalosis
- metabolic = HCO3 >24
- respiratory = PaCO2 <4.7
33
how can COPD cause mixed metabolic and respiratory acidosis
- hypoxic hypoxia increase lactic acid = decreases HCO3
- decreased ventilation increase PaCO2 = increases PaCO2
34
what causes H+ gain
- acid production
- HCO3 loss in stool
- ingestion of acid
35
what causes H+ loss
- acidic gastric acid fluid in vomiting
- loss of H+ in urine
36
how is H+ maintained in normal limits
- H+ with blood buffer or intracellular buffer
- reduction of H2CO3 by CO2 elimination
- renal elimination of H+
- H+ moves into cells in exchange for K+
37
how is normal plasma ph maintained
- chemical buffer of the blood cells
- renal regulation of H+ and HCO3
- respiratory regulation
38
how does the chemical buffer system work
- reduces affect of adding or removing H+
- ions are removed from the solution but not eliminated
- incorporated into a buffer pair
39
how does the bicarbonate buffer system work
- increase or decrease H+
- cant buffer pH changes cause by its own system
40
how does the haemoglobin buffer work
RBCs buffer H+ from metabolically produced CO2
41
how does protein buffer system work
- albumin
- has both acidic and basic groups that buffer
42
how does the phosphate buffer system work
- intracellular and urinary buffer
- excess phosphate filtered through the kidneys
43
what is the respiratory regulation of ph
- alters pulmonary ventilation and so alters excretion of H+, generating CO2
44
what is the respiratory regulation when there is an increase in arterial H+
- increase pulmonary ventilation
- increase CO2 blown off
45
what is the respiratory regulation when there is a decrease in arterial H+
- decreased pulmonary ventilation
- increased CO2 accumulation
46
what stimulate the peripheral chemoreceptors
- decreased PaO2
- increased H+
- increased PaCO2
47
what stimulates the central chemoreceptors
- increase H+
- increased PaCO2
48
how does renal regulation of pH occur
- removes H+ and adds HCO3 to body fluids
- ammonia secretion
49
what is the renal regulation when there is an increase in PaCO2
- increased renal reabsorption or generation of HCO3
- increase in Plasma
- increase in pH
50
what is the renal regulation when there is a decrease in PaCO2
- increased renal excretion of HCO3
- decreased plasma
- decreased pH
51
how is hydrogen secretion increased
- increase secretion into renal tubes so more in urine
- increase HCO3 reabsorption into the blood
- decreases pH
52
how is hydrogen secretion decreased
- decrease H+ secretion into renal tubules
- decrease HCO3 reabsorption into blood
- increase pH
53
what is the renal compensation in compensatory chronic respiratory acidosis
- decreased urea production and increased glutamate, which becomes ammonia and HCO3
54
what is the renal compensation in compensatory chronic respiratory alkalosis
- increase in activity of type b intercalated cells
- help to secrete HCO3 into tubule lumens to increase concentration
55
what is the renal response in respiratory acidosis
- increases H+ excretion
- increases HCO3 reabsorption and regeneration
56
what is the respiratory and renal response in metabolic acidosis
- resps = decrease pH and increase CO2, increase vents
- renal = increase H+ excretion
57
what is the renal response in respiratory alkalosis
increase HCO3 excretion
58
what is the renal and respiratory responses in metabolic alkalosis
- resps = decrease ventilation and increase CO2
- renal = increase HCO3 excretion
59
what does ROME stand for in ph balance
Respiratory
Opposite
Metabolic
Equal
60
what is type I respiratory failure
- failure to oxygenate
- hypoxemia without hypercapnia
- low PO2
- normal PCO2
61
what is type II respiratory failure
- failure of alveolar ventilation
- hypoxaemia with hypercapnia
- PO2 low
- PCO2 high
62
how does severe asthma cause respiratory acidosis
hypoxemia -> reduce tissue oxygenation -> anaerobic metabolism -> lactic acidosis
63
how does severe asthma lead to respiratory alkalosis
hyperventilation -> hypocapnia -> respiratory alkalosis
64
what order do you use to interpret bloods for oxygenation and respiratory failure
1. oxygenation (low = resps, high = metabolic)
2. alkalosis or acidosis
(both for which respiratory failure)
3. work out which pathway
65
