Oxygen transport Flashcards
what are the 2 ways oxygen is transported in the blood?
A) 2% is dissolved in plasma
B) 98% is chemically bound to hemoglobin
100 ml blood contains _____ mL of DISSOLVED oxygen at PO2 = 100 mmHg
(this is asking about O2 in plasma, not Hb bound)
0.3 ml
Each gram of Hb can combine with ____ ml of oxygen
1.34 ml
Normally, blood contains ≈ ___g Hb/100ml of blood
15g Hb/100ml of blood
- or 150g/L
oxygen carrying capacity of Hb is __ ml oxygen/100 ml blood
in other words, how much oxygen can 100ml of blood carry?
20 ml
15 X 1.34 = 20 ml oxygen/100 ml blood
The amount of oxygen in the blood (sum of both forms, dissolved and bound to hemoglobin) is called the “____________”
oxygen content of blood
T/F:
A) The O2 content of arterial blood (CaO2) is ≈ 15 vol%
AND
B) the O2 content of venous blood (CvO2) ≈ 10 vol%
False
Arterial = 20 vol%
Venous = 15 vol%
both oxygen carrying capacity and oxygen content depend on what?
how are these values expressed?
the amount of hemoglobin in an individual’s blood
are expressed as volume of oxygen present per unit volume of blood
the SaO2 (hemoglobin saturation ratio) is expresses a _________, not a ___________
the SaO2 expresses a percentage and not a unit volume of oxygen
T/F: SaO2 and oxygen content are interchangeable
FALSE
two patients may have the same SaO2 but one could have a low blood hemoglobin concentration because of anemia
Venous blood entering the pulmonary capillaries has a PO2 of ____ mm Hg; and the Hb is ____% saturated with oxygen
40 mm Hg
Hb is 75% saturated with oxygen
what is the alveolar PO2?
100 mmHg
after equilibration in the lungs, what is the % saturation of hemoglobin?
97%
In the plateau region, at a PO2 _______ mmHg, there is little change in amount of O2 bound to Hb
plateau region = PO2 60-100 mm
T/F: increasing PO2 beyond 100 mmHg does not improve oxygen carriage by Hb significantly
true