Block 2b Gas Transport Flashcards
Venous PO2
40 mmHg
Alveolar PO2
104 mmHg
Arterial PO2
95 mmHg
Interstitial PO2
40 mmHg
Intracellular PO2
23 mmHg
When does Hb dissociation curve become steep?
below 40 mmHg O2
What is the utilization coefficient?
the percentage of blood that gives up its O2 in capillaries
What is the normal utilization coefficient?
25%
What factors cause a right-shift in the Hb dissociation curve?
H+, CO2, T, BPG
What is the Bohr effect?
effect of H+, CO2, T, & BPG to favor O2 dissociation at higher PO2
How does affinity of Hb for CO compare to that of O2?
250x
Intracellular PCO2
46 mmHg
Interstitial PCO2
45 mmHg
Venous PCO2
45 mmHg
Arterial PCO2
40 mmHg
Alveolar PCO2
40 mmHg
How is CO2 transported in blood?
1) soluble, 2) carbaminohemoglobin 3) HCO3- product of CA
What percentage of CO2 is transported via HCO3- product of CA?
70%
What percentage of CO2 is transported via carbaminohemoglobin?
23%
What is the haldane effect?
binding of O2 displacing CO2 from Hb
What is the chloride shift?
HCO3- exchanged for Cl- in RBC via SLC4A1 transporter
What are the determinants of interstitial PCO2 & PO2?
blood flow & metabolism
What is the O2 content of blood?
20 mLO2 /dL
