Gas Transport

Gases Gases TransportationTransportation

Gases Gases TransportationTransportation

by Assist Prof Chote Werawong

Oxygen Oxygen transporttransportOxygen Oxygen transporttransport

5Dissolve in plasma % 0.003 x Po2 = 0.3 ml O2/dL of blood

99995% 1.34 x Hb x Saturation

1.34 x 15 x 100% = 20 ml O2/dL of blood

Red blood cell Red blood cell and hemoglobinand hemoglobinRed blood cell Red blood cell

and hemoglobinand hemoglobin Red blood cell Red blood cell - size : - size : 75 8. micron (cap = ) 75 8. micron (cap = ) - shape : - shape : 9999, 120 9999, 120 - number : - number : 54 48M = . , F = . (million/micr 54 48M = . , F = . (million/micr

) ) Hb Hb 29 = 900pg in each RBC gm in male 29 = 900pg in each RBC gm in male Hb Hb 991 :1.39 991 :1.39 Hb 15 gm Hb 15 gm 99= 20.1 / 100 99= 20.1 / 100

- - 4HbA : heme (globin Fe 2+ 9 99999) + - 99999 9 99999:+ - 9 9999:1

Hb + O2

-- > HbO2

= (oxyhemoglobin)

HbO2

---- > Hb + O2

(deoxyhemoglobin)

99 2 -- > Fe 3+ (methemoglobin = HbM)

9- : inccol l oi dosmoti c P, l oss f romfi l trati on

Hemoglobin = Hb Hemoglobin = Hb ( (cont)cont)


Oxygen saturation

= (O2

bound to Hb/ O2

capacity of Hb) x 100%

100 15blood ml = gm Hb

1 gm Hb = 1.3 9 ml O2

(O2

sat = 100%

)

blood 100 ml = 15 x 1.39 = 20.1 ml/dL

Oxygen Oxygen hemoglobin hemoglobin

dissociation curvedissociation curve

Oxygen Oxygen hemoglobin hemoglobin

dissociation curvedissociation curve

Oxygen hemoglobin Oxygen hemoglobin dissociation curve dissociation curve (con (con

t)t)


t)t)


t)t)


t)t)

1Slow st -- 4Hb > rd 20Hb time

- 20 50 9mmHg = steep region

0%HbO2

- 50 100mmHg = plateau region

9999999 99999 P50 - 2628= mmHg

H+ &pH(Bohr’seffect)

CO2

+H2

-- O > H2

CO3

-- > H+ + HCO3

-

Temperature

2 ,3 diphosphaglycerate - (2,3DPG,DPG1

)

blood transfusion 15 mol/Hb 1 gm

HbF<HbA

Affinity of Hb for oxy Affinity of Hb for oxygengen

Affinity of Hb for oxy Affinity of Hb for oxygengen

Carbonmonaxide = CO 210( time o

f oxygex)

- -- : Hb + CO > HbCO (carboxyhemoglobin)

Anemia

Affinity of Affinity of HbHb for oxygen for oxygen(cont)(cont)


Myoglobin = Mb (5 time of Hb)



-510Dissolve in plasma %

00006. ml/mmHg of CO2

99 99999/

9 9 99 999994 6 = 2 .5 /1 0 0

9 9 99 999994 0 = 2 .0 /1 0 0

9 92

- 480100 42 201exp = ( . )/ x . = ml/min

CarbondioxidCarbondioxid e transportati e transportati

onon

CarbondioxidCarbondioxid e transportati e transportati

onon

Carbondioxide tr Carbondioxide transportationansportation (cont)(cont)

Carbondioxide tr Carbondioxide transportationansportation (cont)(cont)

- 1030Proteinbinding % (carbamino compound)

-R NH2

+ CO2

-- > H+ - -+ R NH COO-

9 9999999999 (> 100 sec)

( 1 3 , 0 0 0 )

9 + -- 9999999999 9999999+ > ( )

9 + + HbO 2 -- > HHb + O2

(Bohr’s effect)

99- -- = chloride shift > inc osmotic P

Carbondioxide di Carbondioxide di ssociation curve ssociation curve


Bohr

H+ + HbO 2 +CO2

------------- < >HHbCO2

+O2

Haldane

-- Haldane effect > pulm capillary -- Haldane effect > pulm capillary

-- Bohr effect > tissue -- Bohr effect > tissue

Volatile acid ( 24000, meq/l)

Non volatile acid or fixed acid 50(meq/l)

H2

SO4

- 999 99999 9- 99999999: :

lactic acid

H3

PO4

- : phospholipid

- HCl : stomach

- Ketoacid: fatty aci d

pHpHpHpH

Buffer

Ventilation

Kidney

HH++ regulation regulationHH++ regulation regulation

1. bicarbonate system (HCO3

- & H2

CO3

)

H2

CO3

-- > CO2

+ H2

O

mass action law - : K = [H+][HCO3

- ] / [H2

CO3

]

9999 999 pH = pK+ log [HCO3

- ] / [H2

CO3

]

pH = pK + log [HCO3

- ] / sol co 2 9 9992

BufferBufferBufferBuffer

Buffer Buffer (cont(cont.).)

Buffer Buffer (cont(cont.).)

AA BB CC DD EE

HCO3- 24 24 24 10 40

Pco2 40 20 70 40 40

pHpH 7.407.40 7.707.70 7.157.15 7.027.02 7.627.62

AA BB CC DD EE

HCO3- 24 24 24 10 40

Pco2 40 20 70 40 40

pHpH 7.407.40 7.707.70 7.157.15 7.027.02 7.627.62

pH = pK + log [HCO3

- ] / sol co 2 xPco

2

pH = pK + log [HCO3

- ] / sol co 2 xPco

2

pk = 6.1, sol CO2

003= . 61pk = . , sol CO2

003= .

Buffer Buffer (con(cont.)t.)

Buffer Buffer (con(cont.)t.)

2. phosphate system (H2

PO4

- & HPO4

=)

3. plasma protein -R NH

2 -- > H+ -+ R NH-

4. hemoglobin H+ -- + Hb > HHb (isodydric effect)

- pH= 7.35 7.45(7.4)

acidosis, alkalosis

Po2

- = 8 0 1 0 0 ( )

Pco2

- 35 45 40= mmHg ( )

hypercapnea, hypocapnea (+ -- 10 0 08mmHg > pH . )

999999 HCO3

- - 2226= meq/l

metabolic acidosis, alkalosis

Arterial blood Arterial blood gasesgases

Arterial blood Arterial blood gasesgases

Respiratory acidosis- hypoventilation, CNS depr essant

- increase reabsop HCO3

- , secret H+

Respiratory alkalosis- hyperventilation- increase reabsop H+ , secret HCO

3

-

Acid-base Acid-base imbalanceimbalanceAcid-base Acid-base imbalanceimbalance

- Acid base imbalan- Acid base imbalancece (cont) (cont)

- Acid base imbalan- Acid base imbalancece (cont) (cont)

Metabolic acidosis

- anaerobic, ketoacidosis, acid intake

- increase respiratory rate

Metabolic alkalosis- vomiting, base intake, drug

- decrease respiratory rate

Exercise Exercise II

Exercise Exercise II

AA B B C C D D E E

HCO3- 24 24 24 10 40

Pco2 40 20 70 40 40

Po2 100 120 70 110 80

pH 7.40 7.70 7.15 7.02 7.62

status normal R. Al. R. Ac. M. Ac.

M .Al.

AA B B C C D D E E

HCO3- 24 24 24 10 40

Pco2 40 20 70 40 40

Po2 100 120 70 110 80

pH 7.40 7.70 7.15 7.02 7.62

status normal R. Al. R. Ac. M. Ac.

M .Al.

What is his acid base

status?

What is his acid base

status?

Exercise Exercise IIII

Exercise Exercise IIII

AA B B C C D D E E

HCO3- 24 12 42 40 10

Pco2 60 20 70 10 65

Po2 70 120 70 110 65

pH 7.22 7.40 7.40 8.22 6.81

AA B B C C D D E E

HCO3- 24 12 42 40 10

Pco2 60 20 70 10 65

Po2 70 120 70 110 65

pH 7.22 7.40 7.40 8.22 6.81

Gas Transport

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Transcript of Gas Transport