module 11 acid base

Question 1

acid-base homeostasis

Answer 1

pH negative logarithm of H+ concentration 
normal h+: about 40 
nml pH: 7.35-7.45
inc pH: few H+ (alkaline)
dec. pH: a lot of H+ (acidic)
PaCO2: 35-45
HCO3: 22-26

Question 2

normal cellular metabolism

Answer 2

releases acid (carbonic, metabolic) that must be excreted

Question 3

3 mechanisms regulate

Answer 3

buffers: chemicals released to balance pH (HCO3 and H+)
respiratory: PaCO2
renal: bicarbonate: HCO3

Question 4

respiratory regulation

Answer 4

2nd defense
cells continuously make CO2: CO2 + H2O = carbonic acid (H2CO3)
- lung can excrete
Resp. system adjusts amount of H2CO3 in system by altering rate and depth of respirations
- use chemoreceptors

Question 5

chemoreceptors and regulation

Answer 5

sense CO2, PaO2, pH

• inc. H2CO3 (CO2) -> inc. rate and depth -> inc. removal
• dec. H2CO3 -> dec. rate and depth -> retain CO2

Question 6

for respiratory regulation to work need

Answer 6

normal

• chemoreceptors
• respiratory neurons
• motor nerves to resp. muscles, diaphragm, chest wall
• airways, lungs, pulm. circulation

Question 7

PaCO2 indicates

Answer 7

how well resp. system excreting H2CO3

• inc. PaCO2: resp rate and depth insufficient or lung disease prevented excretion
• dec. PaCO2: lungs excreted too much, depth and rate excessive

Question 8

comensation

Answer 8

respiratory response to any acid imbalance not r/t CO2

• does not correct pH disorder, but compensates by adjusting pH towards normal
• other chemical values made abnormal in process

Question 9

deficit of any acid except CO2

Answer 9

hypoventilation; retain CO2 (acid) -> dec. pH

Question 10

excess of any acid except Co2

Answer 10

hyperventilation; blow off CO2 (acid) -> inc. pH

Question 11

nml HCO3 to H2CO3

Answer 11

20:1 (buffers)

Question 12

metabolic acidosis

Answer 12

condition leads to excessive acid (not H2CO3)
- inc. acid
- dec. base
- combo
s/s: 
- HA
- abd. pain 
- CNS depression

Question 13

compensation for metabolic acidosis

Answer 13

hyperventilation 
ABG: 
- dec. bicarb: primary imalance
- dec. CO2: compensation
- pH: low to normal

Question 14

respiratory acidosis

Answer 14

conditions increased H2CO3
impair resp excretion 
- impaired gas exchange
- inadequate neuromuscular function 
- impaired resp. control in brainstem

Question 15

resp. acidosis s/s

Answer 15

HA
inc. HR
cardiac dysrhythmia
neuro abnormalities

Question 16

respiratory acidosis compensation

Answer 16

inc. renal excretion of metabolic acid, retain HCO3
ABG
- CO2: inc: primary imbalance
- HCO3: inc. compensation 
-pH: low to normal

Question 17

metabolic alkalosis

Answer 17

condition -> dec. of acid (except H2CO3)

• inc. base (HCO3)
• dec. acid
• combo
• • over the counter bicarb: antacids
• • emesis/ suction

Question 18

metabolic alkalosis s/s

Answer 18

extracellular fluid depletion that caused it 
- postural hypoTN
hypokalemia
- muscle weakness
inc. neuromuscular excitability

Question 19

metabolic alkalosis compensation

Answer 19

hypoventilation: retain H2CO3
ABG:
- inc. HCO3: primary imbalance
- inc. CO2: compensation 
- inc. pH

Question 20

respiratory alkalosis

Answer 20

condition -> dec. H2CO3
- hyperventilation
-- hypoxemia
-- pain 
-- psychological distress
s/s:
neuromuscular excitability

Question 21

respiratory alkalosis compensation

Answer 21

dec. renal excretion of metabolic acid
-> dec. HCO3 concentration
ABG:
- dec. CO2: primary imbalance
- dec. HCO3: compensation
- inc or normal pH

Question 22

carbonic anhydrase (bicarbonate buffer system)

Answer 22

HCO3 + H+ -> CO2 + H2O

Question 23

inc. metabolic acid and bicarb buffer system

Answer 23

inc. metabolic acid (lactic acid): releases H+

- > HCO3 + H+ –(carbonic anhydrase)–> H2CO3: excreted in lungs

Question 24

dec. metabolic acid and bicard buffer system

Answer 24

dec. metabolic acid -> carbonic acid releasing H+

H2CO3 HCO3 + H+

Question 25

henderson-hasselbalch equation

Answer 25

pH= pKa + log (HCO3/H2CO3)

pKa: dissociation constant for any particular acid