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Integrative Physiology. O2/CO2 transport disorders. Respiratory disorders. Circulation disorders. Acid -Base disorders. Acid -Base disorders. Osmolarity disorders. Electrolyte disorders. Volume disorders. Gastrointestinal disorders. Kidney disorders.

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integrative physiology
IntegrativePhysiology

O2/CO2 transport disorders

Respiratorydisorders

Circulationdisorders

Acid-Base disorders

Acid-Base disorders

Osmolarity disorders

Electrolytedisorders

Volume disorders

Gastrointestinaldisorders

Kidneydisorders

slide2

Homeostasis of internal enviroment

Disorders of the acid-base chemistry, influence of respiration, lungs and altered metabolism

slide3

Inputs

Balance between input and output flow

Storage

?

Outputs

retention

?

depletion

slide4

External environment of organism

Balance estimation

Concentrations

extracellular fluid - ECF

intracellular fluid - ICF

Metabolism

slide5

External environment of organism

Balance estimation

Concentrations

plasma

Lymph

capillaries

extracellular

fluid -ECF

interstitial fluid - ISF

intracellular fluid - ICF

Metabolism

slide6

External environment of organism

intravascular

blood cells

plasma

Lymph

fluid

(part of ICF)

capillaries

capillaries

extracellular

fluid -ECF

interstitial fluid - ISF

intracellular fluid - ICF

Metabolism

slide7

External environment of organism

intravascular

blood cells

plasma

Lymph

fluid

(part of ICF)

extracellular fluid -ECF

capillaries

capillaries

transcellular fluid

interstitial fluid - ISF

intracellular fluid - ICF

Metabolism

slide8

External environment of organism

GIT

Lungs

„exchangers“

Kidney

intravascular

blood cells

plasma

Lymph

fluid

(part of ICF)

extracellular fluid -ECF

capillaries

transcellular fluid

interstitial fluid - ISF

intracellular fluid - ICF

Metabolism

slide9

External environment of organism

„exchangers“

GIT

Lungs

Kidney

intravascular

blood cells

plasma

Lymph

fluid

(part of ICF)

extracellular fluid -ECF

Circulation

capillaries

„mixing“

transcellular fluid

interstitial fluid - ISF

intracellular fluid - ICF

Metabolism

slide10

External environment of organism

GIT

Lungs

„exchangers“

Kidney

intravascular

blood cells

plasma

Lymph

fluid

(part of ICF)

extracellular fluid -ECF

Circulation

capillaries

„mixing“

transcellular fluid

interstitial fluid - ISF

intracellular fluid - ICF

Metabolism

slide11

External environment of organism

CO2

H+

GIT

Lungs

„exchangers“

Kidney

intravascular

blood cells

plasma

Lymph

fluid

(part of ICF)

extracellular fluid -ECF

Circulation

capillaries

„mixing“

transcellular fluid

interstitial fluid - ISF

intracellular fluid - ICF

ACID-BASE

BALANCE

Metabolism

slide12

Practically complete reabsorbtion of HCO3-

H+ excretion

Acid-Base Balance

60 mmol/24 h

CO2

HCO3-

H2CO3

TA+NH4+

H+

H2O

A-

20 000 mmol/24 hod

60 mmol/24 hod

Metabolic production of CO2

Metabolic production od strong acids

buffering systems of the blood
Buffering systems of the blood

+

+

CO2

H2O

H2CO3

H+

HCO3-

HBuf

H+

+

Buf-

H+

+

Hb-

HHb

H+

+

Alb-

HAlb

H+

+

HPO42-

H2PO4-

non-bicarbonate buffers

Buf = Hb + Alb + PO4-

buffering reactions

HCO3-

CO2

H2CO3

H2O

H+

HBuf

Buf-

Buffering reactions
acid base balance

AcidBalance

BaseBalance

Acid-Base Balance

Productionof HCO3-

Productionof H+

Diet -> 2H++SO42-

Diet ->H+ + HPO4-

Diet -> 3K++ 3 HCO3-

Removalof H+

Removalof HCO3-

2H++2HCO3- -> 2CO2+2H2O

Glucose -> 3H++Citrate-

Excreteorganicanions

Add „new“ HCO3-

2NH4++SO4-

H2PO42-

3K++Citrate-

Urine

h formation removal
H+formation/removal

Reactionsthatyields H+ (more negative charge in productsthan in substrates)

Glucose -> Lactate- + H+

C16fattyacids-> 4ketoacidsanions- + 4 H+

Cysteine -> urea + CO2+H2O+SO42- + 2 H+

Lysine+ -> urea + CO2 + H+

Reactionsthatremoves H+ (more net positive charge in productsthan in substrates)

Lactate- + H+-> Glucose

  • Glutamate- + H+-> urea + CO2+H2O
  • Citrate- + 3 H+-> CO2+H2O

H+ are neitherproduced nor removed(neutrals to neutrals)

  • Glucose -> Glycogenor+ CO2+H2O
  • Triglyceride -> CO2+H2O
  • Alanine -> urea + glucoseorCO2+H2O
slide18

Diet

ECF

2CO2+2H2O

2 H+

Sulfur-AA

2 HCO3-

SO42-

urine

Glutamine

SO42-

2NH4+

2NH4+

kidney

ECF

Diet

H+

CO2+H2O

HCO3-

RNA-P-

HPO42-

CO2+H2O

urine

kidney

HPO4-

H+

slide19

liver

Diet

OA utilisation

Glucose

OA-

ECF

HCO3-

OA-

H+

H+

K+

CO2+H2O

CO2+H2O

K+

OA-

OA-

kidney

urine

slide20

Acid-base regulation

-

CO2

HCO3

TA + NH4+

H2CO3

CO2 balance

H2O

H+

H+ balance

  • Buffer systems (msec)
  • Respiration control (12 hours)
  • Kidney control (3-5 days)

HBuf

Buf -

Exchange H+/K+ H+/Na+ between cells and ECF

Role of liver in AB regulation

slide21

Acid-base disturbances:

-

CO2

HCO3

TA + NH4+

H2CO3

CO2 balance

H2O

H+

H+ balance

HBuf

Buffer system acid-base disturbances

Buf -

Balance acid-base disturbances:

- metabolic acidosis/alkalosis

- respiration acidosis/alkalosis

slide22

-

CO2

HCO3

TA + NH4+

H2CO3

CO2 balance

H2O

H+

H+ balance

HBuf

  • Buffers system acid-base disturbances:
    • Dilutional acidemia
    • Contractional alkalemia
    • Hypoproteinemic alkalemia

Buf -

slide23

Dilution

-

CO2

HCO3

TA + NH4+

H2CO3

CO2 balance

H2O

H+

H+ balance

HBuf

  • Buffers system acid-base disturbances:
    • Dilutional acidemia

Buf -

slide24

Dilution

equilibrium shift

-

CO2

HCO3

TA + NH4+

H2CO3

CO2 balance

H2O

H+

H+ balance

HBuf

  • Buffers system acid-base disturbances:
    • Dilutional acidemia

Buf -

slide25

Hemoconcentration

-

CO2

HCO3

TA + NH4+

H2CO3

CO2 balance

H2O

H+

H+ balance

HBuf

  • Buffers system acid-base disturbances:
    • Contractional alkalemia

Buf -

slide26

Hemoconcentration

CO2

-

HCO3

TA + NH4+

H2CO3

CO2 balance

H2O

H+

H+ balance

HBuf

  • Buffers system acid-base disturbances:
    • Contractional alkalemia

Buf -

slide27

Hemoconcentration

CO2

-

HCO3

equilibrium shift

TA + NH4+

H2CO3

CO2 balance

H2O

H+

H+ balance

HBuf

  • Buffers system acid-base disturbances:
    • Contractional alkalemia

Buf -

slide28

Acute hypoproteinemia

-

CO2

HCO3

TA + NH4+

H2CO3

CO2 balance

H2O

H+

H+ balance

HBuf

Buffers system acid-base disturbances:

Hypoproteinemic alkalemia

Buf -

slide29

Acute hypoproteinemia

-

CO2

HCO3

TA + NH4+

H2CO3

equilibrium shift

CO2 balance

H2O

H+

H+ balance

HBuf

Buffers system acid-base disturbances:

Hypoproteinemic alkalemia

Buf -

slide30

Acid-base disturbances:

-

CO2

HCO3

TA + NH4+

H2CO3

CO2 balance

H2O

H+

H+ balance

HBuf

Buffer system acid-base disturbances

Buf -

Balance acid-base disturbances:

- metabolic acidosis/alkalosis

- respiration acidosis/alkalosis

slide31

PCO2torr

90

pH=7,1

pH=7,2

pH=7,37

pH=7,3

pH=7,43

80

pH=7,5

Sustained respiratory acidosis

Acute respiratory acidosis

70

pH=7,6

60

Sustained metabolic alkalosis

50

Akute metabolic alkalosis

Acute metabolic acidosis

40

30

Sustained metabolic acidosis

Acute

respiratory acidosi

Sustainedrespiratoryalkalosis

20

10

-20

-15

-10

15

-5

-25

25

0

30

10

5

20

Base Excessmmol/l

slide32

Bicarbonate reabsorbtion

(4) diarhoea

TA+NH4

+

(3) losses of

HCO3-

(1) Increased metabolic production of strong acids

(2) Disorder of H+ excretion

H+excretion

CO2

HCO3-

H2CO3

H+ retention

H+ depletion

H+

H2O

HBuf

A-

Buf -

slide33

Gastrointestinal losses of bicarbonate

NH3

  • Metabolic acidosis with:
  • increased anion gap
  • normal anion gap

H+

A-

HCO3-

Cl-

H+

Accumulation of anions of strong acids

(laktate acidosis

ketoacidosis

uremic acidosis)

Cl-

NH4+

Cl-

Urea

Overdosis of NH4Cl

K+

Na+

Normal anion

gap

Anion gap

Na+

Increased

anion

gap

Na+

Na+

In urine:

[K+]+[Na+]-[Cl-] < 0

HCO3-

HCO3-

HCO3-

Cl-

Relativeaccumulationofchlorides

Cl-

NH3

Cl-

Cl-

HCO3-

HCO3-

H+

Decreasedacidification

(tubularacidosis, hypoaldosteronisms,

decreasesglomer. filtration)

HCO3-

Cl-

NH4+

K+

Cl-

Na+

in urine:

[K+]+[Na+]-[Cl-] >= 0

slide35

Cl-

Na+

H+

H20 + CO2

HCO3-

H2O

H2O

NHE

AE

Colon

H+

Na+

HCO3-

Cl-

H20 + CO2

HCO3-

Na+

Cl-

HCO3-

H2O

slide36

Cl-

H+

H20 + CO2

HCO3-

HCO3-

Na+

Na+

H2O

H2O

H2O

AE

NHE

Colon

H+

Na+

HCO3-

Cl-

H20 + CO2

HCO3-

Hypotonic fluid loss

Cl-

HCO3-

Na+

H2O

Hypertonicdehydratation

Cl-

Alkalic diarrhoea

HCO3-

Hyperchloremicacidosis

slide37

Cl-

Cl-

H+

H20 + CO2

HCO3-

HCO3-

Na+

Na+

H2O

H2O

H2O

AE

NHE

Colon

K+

Potassiumloss

H+

Na+

HCO3-

Cl-

H20 + CO2

HCO3-

Hypotonic fluid loss

Cl-

HCO3-

Na+

H2O

Hypertonicdehydratation

Cl-

Severe alkalicdiarrhoea

HCO3-

Hyperchloremicacidosis

slide38

Cl-

Histidine

H.Histidine+

Cl-

H20 + CO2

H+

HCO3-

Na+

Na+

H2O

H2O

H2O

NHE

Colon

AE

H+

Na+

HCO3-

Cl-

H20 + CO2

HCO3-

Hypotonic fluid loss

Na+

Cl-

HCO3-

H2O

Hypertonicdehydratation

HCO3-

Acidic diarrhoea in DRA, down-regulatedadenoma

Cl-

Hypochloremicalkalosis

slide39

Cl-

HCO3-

Complete reabsorbtion

norm

H+

norm

Normalacidification

proximaltubularrenalacidosis

NH4+

Cl-

Rateofbicarbonatereabsorbtion

NH4+

Cl-

b

a

c

K+

normal

anion gap

Anion gap

Na+

Na+

Na+

HCO3-

Normalurine

anion

gap

HCO3-

In urine:

[K+]+[Na+]-[Cl-] < 0

Cl-

Plasma levelof HCO3-

20

10

25

15

Cl-

NH3

Cl-

HCO3-

Hyperchloremicacidosiswithnormal anion gap

Cl-

HCO3-

H+

Decreasedacidification

(tubularacidosis, hypoaldosteronisms,

decreasesglomer. filtration)

HCO3-

Cl-

NH4+

K+

Positive urine

anion

gap

Cl-

c

b

a

Na+

norm

In urine:

[K+]+[Na+]-[Cl-] >0

pH=5,5

pH=6,5

pH=7,8

pH=5,5

slide40

Bicarbonate reabsorbtion

Metabolicalkalosis

TA+NH4

+

hyperaldosteronism

katabolism

(7) K+

depletion

(6) vomiting

H+

K+

Overdosis HCO3-infusion

H+excretion

CO2

HCO3-

H2CO3

Retence H+

Retence H

H+

H2O

HBuf

A-

Buf -

slide41

PCO2torr

90

pH=7,1

pH=7,2

pH=7,37

pH=7,3

pH=7,43

80

pH=7,5

Sustainedrespiratoryacidosis

Acute respiratory acidosis

70

pH=7,6

60

Sustained metabolic alkalosis

50

Akute metabolic alkalosis

Acute metabolic acidosis

40

30

Sustainedmetabolicacidosis

Acute

respiratory acidosi

Sustained respiratory alkalosis

20

10

-20

-15

-10

15

-5

-25

25

0

30

10

5

20

Base Excessmmol/l

slide43

HCO3-

H+

CO2

Cl-

H2CO3

H2CO3

Balanced

Stomach

CO2

H2O

H2O

Cl-

Cl-

H+ +HCO3-

H+

H2CO3

CO2

CO2

H2O

Duodenum andpancreas

slide44

Cl-

Hypotonic fluid loss

H+

Hypertonicdehydratation

HCO3-

H+

CO2

Cl-

H2CO3

H2CO3

Unbalanced, HCO3-retension

Stomach

CO2

H2O

H2O

Cl-

hypochloremia

Hypochloremicalkalosis

Cl-

H+

H++HCO3-

CO2

H2CO3

CO2

H2O

Duodenum andpancreas

slide45

Cl-

Na+

Na+

Cl-

Cl-

Remnant of sodium is exchanged with and H+

K+

Na+

Na+

H+

K+

H+

NH4+

Primary cause: Losses of Cl- a H+ by vomiting

Glomerular filtraton (norm)

Glomerulal filtration (hypochloremic alkalosis)

Na+

Na+

Cl-

Depletion of chlorides

Cl-

H+

Na+/Cl- reabsorbtion is diminished

Readsorbtion of sodium and chlorides

Metabolic alkalosis

H+

H+

K+

K+

Increased exchange Na+ with K+ and Na+ with H+

Intracellular fluid

K+

Potassiumdepletion

H+

Excretion of potassium increases,

acidification of urine regardless of alkalosis

K+

H+

K+

H+

Paradoxal urine acidification

Increases lossse ofn

slide46

PCO2torr

90

pH=7,1

pH=7,2

pH=7,37

pH=7,3

pH=7,43

80

pH=7,5

Sustained respiratory acidosis

Acute respiratory acidosis

70

pH=7,6

60

Sustained metabolic alkalosis

50

Akute metabolic alkalosis

Acute metabolic acidosis

40

30

Sustained metabolic acidosis

Acute

respiratory acidosi

Sustainedrespiratoryalkalosis

20

10

-20

-15

-10

15

-5

-25

25

0

30

10

5

20

Base Excessmmol/l

slide47

PCO2torr

90

pH=7,1

pH=7,2

pH=7,37

pH=7,3

pH=7,43

80

pH=7,5

Sustained respiratory acidosis

Acute respiratory acidosis

70

pH=7,6

60

Sustained metabolic alkalosis

50

Akute metabolic alkalosis

Acute metabolic acidosis

40

30

Sustained metabolic acidosis

Acute

respiratory acidosi

Sustainedrespiratoryalkalosis

20

10

-20

-15

-10

15

-5

-25

25

0

30

10

5

20

Base Excessmmol/l

slide48

Arterial blood at pH=7,4

Concentration of O2

Oxygen released

due drop

PO2

Oxygen released due

to shift

of dissotiacion curve

(Bohr effect)

Venose blood at pH=7,2

PO2

PaO2

PvO2

slide49

Arterial blood

at pH=7,6

(alkalemia)

Arterial blood at pH=7,4

(normal conditions)

Release of oxygen

at respiratory alkalosis

Concentration of O2

Release of oxygen

at normal condition

Venous blood

at pH=7,36

(alkalemia)

Venous blood at pH=7,2

(normal conditions)

Decrease of

oxygen delivery

to tissues at

acute

respiratory alkalosis

PO2

normal PaO2

PvO2

High PaO2 during hyperventilation at respiratory alkalosis

slide50

Mixed acid-base disturbances - examples

PCO2torr

90

pH=7,1

pH=7,2

pH=7,37

pH=7,3

pH=7,43

80

pH=7,5

Sustained respiratory acidosis

Acute respiratory acidosis

70

pH=7,6

60

Sustained metabolic alkalosis

50

Akute metabolic alkalosis

Acute metabolic acidosis

40

30

Sustainedmetabolicacidosis

Acute

respiratory acidosi

Sustained respiratory alkalosis

20

10

-20

-15

-10

15

-5

-25

25

0

30

10

5

20

Base Excessmmol/l

Metabolic acidosis

+ respiratory acidosis

Diarrhoea -> metabolic acidosis

+ vomiting -> metabolic alkalosis

+ catabolism, ->lactate metabolic acidosis

Metabolic acidosis

+ respiratory alkalosis

slide52

K+mmol/l

C

D

H+

H+

H+

H+

K+

K+

K+

K+

D:

Rapid alkalinization - H+/K+ - dangeroushypokalemia

K+

K+

C:longlastingacidemia- K+ depletion

8

7

H+

H+

6

K+

Normal kalemiarange

B

K+

5

A

4

3

2

1

A:Norm

pH

7,3

7,2

7,0

7,5

7,1

6,9

7,8

7,4

7,6

7,7

H+

H+

K+

K+

B:Acidemia- exchangeK+/ H+

K+

slide53

K+

Normal or increased intake of potassium

Potassiumdepletion

From10% to 50%

from5% to 30%

slide54

Effectofhypokalemia on ECF volume

Intracellularacidosis in proximal tubule

K+

H+

H+

Enhancedresorption HCO3-

Enhancedresorption Cl-

Enhancedresorption Cl-

slide55

Largedeliveryofsodium in CCD

(e.g. in osmoticdiuresis)

Low chloride in CCS

Potassiumdepletion

Catabolism

Longlastingacidemia

Hypealdosteronism

Diuretics (Furosemid)

K+

K+

slide56

Potassiumretention

Oliguricphase of acute renal failure

Tubulardamage

(e.g. interstitialnephritis, diabeticnephropathy)

Hypoaldosteronism

(m. Addisoni)

K+

K+

acid base balance1
ACID-BASE BALANCE

Danish School of acid-base balance

?

"Modern" approach to acid-base balance by Stewart and Fencl

classical approach of danish school
Classicalapproachof "DanishSchool"

Problem:

How to measurePCO2?

measurement of acid base parameters
Measurement of Acid-Base parameters

pH, pCO2, [HCO3-]

CO2

HCO3-

H2CO3

H2O

H+

HBuf

Buf-

measurement of acid base parameters1
Measurement of Acid-Base parameters

pH, pCO2, [HCO3-]

CO2

HCO3-

H2CO3

H2O

H+

HBuf

Buf-

measurement of acid base parameters2
Measurement of Acid-Base parameters

Alkaline reserve

pH, pCO2, [HCO3-]

CO2

HCO3-

H2CO3

H2O

H+

HBuf

Buf-

measurement of acid base parameters3
Measurement of Acid-Base parameters

P. Astrup 1956

pH, pCO2, [HCO3-]

CO2

HCO3-

H2CO3

H2O

H+

HBuf

Buf-

slide64

Equilibration method for pCO2 measurement by Astrup

High level

pCO

in mixture

2

O

/CO

2

2

Titration curve

pCO2

in measered sample

Low level

pCO

In mixture

2

O

/CO

2

2

pH after equilibration

pH

In blood sample

pH after equilibration

with high pCO

(before equilibration

í

with low pCO

2

2

log PCO

2

pH

slide65

Buffer Base (BB)

BB =[HCO3-]+ [Buf -]

-

CO2

HCO3

depends on cHb

H2CO3

H2O

H+

Normal buffer base:

NBB=41.7+0.42*cHB [g/100ml]

HBuf

Buf -

Base Excess:

BE=BB-NBB

slide66

-

CO2

HCO3

+ 1 mmol H+ added to 1 litre

of blood

H2CO3

H2O

H+

HBuf

Buf -

slide67

-

CO2

HCO3

+ 1 mmol H+ added to 1 litre

of blood

H2CO3

H2O

H+

HBuf

1 mmol/l drop of [HCO3-] + [Buf-]

Buf -

BE=-1mmol/l

slide68

-

CO2

HCO3

+ 1 mmol OH- added to 1 litre

of blood

H2CO3

H2O

H+

HBuf

Buf -

slide69

-

CO2

HCO3

+ 1 mmol OH- added to 1 litre

of blood

H2CO3

H2O

H+

HBuf

1 mmol/l increase of [HCO3-] + [Buf-]

Buf -

BE= 1mmol/l

slide70

log pCO2

Plasma and blood with different hematocrit

BE

curve

BE=0

40 torr

BE=-5

BE=5

BE=-10

pH

7.4

slide71

NBB=41,7 + 0,42 * cHB

Odečet BB

reading of BE

buffer reactions

+

+

CO2

H2O

H2CO3

H+

HCO3-

HBuf

H+

+

Buf-

H+

+

Hb-

HHb

H+

+

Alb-

HAlb

H+

+

HPO42-

H2PO4-

Bufferreactions
buffer reactions1
Bufferreactions

+

+

CO2

H2O

H2CO3

H+

HCO3-

HBuf

H+

+

Buf-

H+

+

Hb-

HHb

H+

+

Alb-

HAlb

H+

+

HPO42-

H2PO4-

Nebikarbonátové pufry

Buf = Hb + Alb + PO4-

buffer reactions2

HCO3-

CO2

H2CO3

H2O

H+

HBuf

Buf-

Bufferreactions
siggaard andersen
Siggaard-Andersen

BB=[HCO3-] +[Buf-] = const

CO2

HCO3-

Siggaard-Andersen

H2CO3

H2O

H+

HBuf

Buf-

slide76

BE=0 mEq/l

BE=-15 mEq/l

siggaard andersen 1960 1962
Siggaard-Andersen (1960-1962)

Definition(forblood in vitro)

- Buffer Base:[BB]=[HCO3-]+[Buf-] (independent on pCO2)

  • NormalBuffer Base:[NBB]
  • [BB] při pH=7.4 při pCO=40 torr atgivenHb
  • (SA nomogram - atnormalalbumins, phophates)
  • Base Excess:[BE]=[BB]-[NBB]

Definitiononlyfor standard conditions

not includedhypo/hyperalbuminemia

hyper/hypophosphatemia

SA nomogram initialy was defined at 38°C

siggaard andersen 1974 1995
Siggaard-Andersen (1974-1995)

Definition(forblood in vitro)

- Buffer Base:[BB]=[HCO3-]+[Buf-] (independent on pCO2)

  • NormalBuffer Base:[NBB]
  • [BB] při pH=7.4 při pCO=40 torr atgivenHb
  • (SA nomogram - atnormalalbumins, phophates)
  • Base Excess:[BE]=[BB]-[NBB]

Definition NBB dependent on Hb, albumin andphosphates

problems of danish school
ProblemsofDanishschool
  • Problems: In patientswithacutedisturbancesofnonbikarbonatebuffers :

e.g. altered plasma concentrations

(if the original SA nomogram isused)

stewart theory 1983

Ca+ Mg+

K+

HCO3-

SID

Buf-

Na+

XA-

Cl-

Stewart theory(1983)

[H+] [OH-] = K\'w

[Buf-]+[HBuf] = [BufTOT]

[Buf-] [H+] = KBuf[HBuf]

[H+] [HCO3-] = M × pCO2

[H+] [CO32-] = N × [HCO3-]

SID+ [H+]–[HCO3-]–

[Buf-]– [CO32-]– [OH-] = 0

Peter Stewart

stewart theory solution of equations

pH = f (pCO2, SID, BufTOT)

Stewart theory – solutionofequations

[H+]4 + (SID+ KBUF) [H+]3+

+(KBUF (SID - [BufTOT])-K\'w-M×pCO2)[H+]2

- (KBUF(K\'w2 + M × pCO2)-N×M×pCO2)[H+]

- K\'w×N×M×pCO2= 0

mathematical wizardry

pH = f (pCO2, SID, BufTOT)

Mathematicalwizardry

dependencyofvariables = causality

Vladimír Fencl

slide83

Stewart‘s „modernapproach

Lungs

Ventilation

Perfusion

KREV

Dependentvariables

[HCO3-]

[Buf-]

[CO32-]

[OH-]

[H+] (pH)

Independent variables

PCO2

SID

[BufTOT]

CO2

Tissues

Perfusion

Metabolism

Transport

CO2

STRONG IONS

KIDNEYS

Filtration

Resorption

Secretion

LIVER

Synthesis

Degradation

GIT

Absorbtion

Secretion

PROTEINS

STRONG IONS

STRONG IONS

balance theory
BALANCE THEORY

Excretion of CO2 in the lungs

The excretion of strong acids in the kidney

CO2production

Metabolic productionofstrongacids

slide86

Blood Volume

Extracellular fluid volume

ArterialPressure

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