Flashcards in Lecture 26 Acid Base Balance Deck (22)
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1
What is essential for cellular function
regulation of [H+] of body fluids is essential
2
what is highly sensitive to [H+]
protein structure and function are highly sensitive to [H+] pH= -log [H+]
increase [H+] = decrease pH
3
Neutral pH
7
[H+] = 10(-7) mol/L = 0.0000001 mol/L
4
Normal pH of ECF
is 7.4 slightly alkaline
5
What is the central acid base system of the body
CO2-bicarbonate system
CO2+ H20 -><- H+ + HCO3-
carbonic anhydrase catalyzes reaction in both directions
6
CO2 acts as
an acid
increase CO2 -> increase [H+] = decrease pH
7
HCO3- acts as
a base
increase HCO3- -> decrease [H+] = increase pH
8
Buffers
bicarbonate (CO2-bicarbonate system)
proteins (e.g. hemoglobin)
phosphate compounds
9
Acid-base regulation
1. role of the respiratory system
2. role of the kidneys
3. acid-base imbalances
10
Role of respiratory system
respiratory system regulates PCO2 of blood via control of ventilation
decrease VA -> increase PCO2 (hypoventilation) -> decrease pH
increase VA-> decrease PCO2 (hyperventilation) -> increase pH
11
Role of the kidneys
kidneys regulate [HCO3-] of blood via H+ excretion and HCO3- reabsorption
increase [HCO3-] -> increase pH
12
acidosis
pH < 7.35
13
alkalosis
pH > 7.45
14
respiratory acidosis/alkalosis
is deviation from normal pH due to change in PCO2
15
metabolic acidosis/alkalosis
is deviation from normal pH due to change in non-CO2 acids/bases -> results in change in [HCO3-]
16
Normal arterial values
pH = 7.4
PCO2 = 40 mm Hg
[HCO3-] = 24mM
17
respiratory acidosis
pH < 7.35
PCO2 > 40 mm Hg
18
respiratory alkalosis
pH > 7.45
PCO2 < 40 mm Hg
19
metabolic acidosis
pH < 7.35
[HCO3-] < 24 mM
20
metabolic alkalosis
pH>7.45
[HCO3-] > 24mM
21
Respiratory compensation
can partially offset metabolic acid base disturbances
e.g. metabolic acidosis with respiratory compensation
pH < 24 mM, PCO2 increase pH)
22
