Acid/Base Reg (lec 16)

Question 1

Methods of H+ regulation in ECF? (3)

Answer 1

1) Buffers (HCO3-, PO4, etc)
2) Respiratory (CO2)
3) Renal (HCO3-)

Question 2

[H+] and pH related how?

Answer 2

inversely

1 unit Δ in pH = 10 x Δ in [H+]

Question 3

Volatile Acid is?

Answer 3

H+ from respiratory CO2 regulation (H2CO3)

Question 4

Fixed Acid is?

Answer 4

from normal and abn processes:
exercise, ketosis, diet

Cannot be excreted by the lungs

Question 5

Fixed Acids from glucogenic catabolism in liver?

Answer 5

Sulfuric, Phosphoric, Dihydrogen/hydrogen Phos

Question 6

Buffers role in H+ reg?

Answer 6

1st-line defense

in ECF, ICF, bone

Question 7

Buffer effectiveness dependent on?

Answer 7

[buffer]

buffer pK

Question 8

Buffers are?

Answer 8

WA + Conj Base (HA/A-)

@ low pH: [HA] > [A-]
@ high pH: [A-] > [HA]

Question 9

If pH = pK?

Answer 9

[HA] = [A-]

Question 10

Most effective buffering happens when?

Answer 10

pH is +/- one unit from pK,

addition/removal of H+ causes little Δ in pH

Question 11

ECF Buffer systems? (4)

Answer 11

1) Bicarb (most important)
2) Hgb
3) Proteins
4) Phosphates

Question 12

ECF Bicarb buffer system?

Answer 12

low pK (6.1) still effective because:
high [buffer]
tight regulation of H2CO3 (lungs) and HCO3- (kidney)

Question 13

ECF Hgb buffer system?

Answer 13

Hb- + H+ HHb

pK 6.5 (ideal)

Question 14

ºBuffer sites on proteins are? (2)

Answer 14

imidazole group on histidine

⍺ amino group all proteins

Question 15

ECF protein buffer system?

Answer 15

Protein- + H+ Hprotein

good pK but low [ ]

Question 16

ECF phosphate buffer system?

Answer 16

HPO4- + H+ H2PO4-
High [ ] in urinary - > Very important as urine buffer,
Low [ ] in blood

Question 17

ICF Buffer systems? (3)

Answer 17

1) Proteins
2) Phosphates
3) Bicarb (2º, low [ ])

Question 18

Bone Buffer system?

Answer 18

takes up H+ in exchange for Na+/K+

Question 19

Buffer response to acid/base Δ results in what?

But not in what?

Answer 19

compensatory minimizing pH Δ

does not return pH to normal

Question 20

Ratio of HCO3-/CO2 should be?

Answer 20

20

Question 21

Δs in [HCO3-] caused by?

Compensated for by?

Answer 21

metabolic disturbances (loss or gain)

kidney (slow) and lungs (fast)

Question 22

Δs in CO2 caused by?

Compensated for by?

Answer 22

respiratory disturbances

kidneys

Question 23

Kidneys compensate for CO2 disturbances how?

Answer 23

synth and reab of new HCO3- ->
excrete H+ as NH4+ ->
raises blood pH

Question 24

Metabolic Acidosis compensation mechanism?

Answer 24

[H+] ingestion, lactic acid form 
or HCO3-fluid loss ->
plasma [HCO3-] ↓ ->
vent ↑ to expel CO2
AND synth/reab of new HCO3- ->
excrete H+ as NH4+ ->

Question 25

Metabolic Alkalosis from ↓ plasma [PCO2] compensation mechanism?

Answer 25

hypervent -> ↑ CO2 loss ->
↓ plasma [PCO2]/↑ pH ->
excretion of HCO3- in urine (alkaline) ->
↓ blood pH

Question 26

Metabolic Alkalosis from ↑ plasma [HCO3-] compensatory mechanism?

Answer 26

vomiting or antacid injestion ->
vent ↓ to ↑ PCO2
AND HCO3- excreted in urine