Lecture 26 Acid Base Balance Flashcards Preview

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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

Renal compensation

can partially offset respiratory acid base disturbances
e.g. respiratory acidosis with renal compensation
pH < 7.35, PCO2 > 40 mm Hg, [HCO3-] > 24 mM
(increase [HCO3-] -< increase pH)