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26 Cards in this Set
- Front
- Back
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How do you calculate how much oxygen is bound to hemoglobin in the blood?
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[Hb] x 1.34 x SaO2
1.34 is a coefficient that says each gram of Hb holds 1.34 O2s Normally this number works out to 15 x 1.34 x .98 = 19.7 ml/100 ml |
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How to calculate how much O2 is carried dissolved in blood
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Henrys law. c = PS
Dissolved = PO2 x S 100 x 0.003 = 0.3 ml/100 ml |
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What does P50 mean? What is its significance.
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P50 reflects the point at which Hb is 50% saturated with oxygen. THE HIGHER THE P50 THE LOWER THE AFFINITY FOR OXYGEN.
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At rest, we normally unload what percent of our O2?
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If you look at the hemoglobin curve, you see that we unload from 100 to 75 or about 25%.
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What is the difference between gas partial pressure and blood gas contents?
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Pressure reflects kinetic energy and it is the component of gas that is freely diffusable. The content reflects the total amount of gas in the blood.
To illustrate the differences between the two think about how Hb has high content but not that much pressure since its not freely diffusable. |
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What is the Bohr effect?
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High CO2, H+ levels decrease Hbs affinity for O2.
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What is CADET shift right?
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CO2, acid, DPG, exercise, temperature all lower Hb's O2 affinity.
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Why is a change in hemoglobin affinity for oxygen benefitial to O2 transport during a condition of exercise?
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When Hb reduces its O2 affinity, the pressure gradient is increased. Remember that the amount of O2 that gets delivered to cells is ultimately proportional to the pressure gradient.
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What is the effect of anemia and CO poisoning on o2 delivery?
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With these conditions, total blood O2 is reduced so PO2 must decrease to very low levels in order to deliver the same amount of O2. The situation is particularly bad for CO poisoning because CO both takes up O2 binding sites and it also causes the O2 that is bound to be bound very tightly.
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What are the four factors determining end capillary PO2?
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1) Metabolic rate of tissue
2) Hb affinity for O2 3) Capillary flow rate 4) Arterial O2 content |
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The majority of CO2 in the blood is carried in what form?
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75% bicarbonate, 20% bound to Hb, 5% dissolved
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What is the haldane effect?
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The deoxygenation of blood increases Hbs ability to carry CO2.
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In an individual who has a deficiency of Carbonic anhydrase, what will you see?
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If you dont have CA, less of the CO2 will be carried as bicarbonate. More will have to be dissolved in the blood. Higher venous CO2 will result.
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What is the chloride shift?
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Movement of HCO3 out of the red blood cell in exchange for chloride from the plasma. This exchange keeps HCO3 in the cell low, which facilitates the conversion of CO2 into HCO3.
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What is the saturation of O2 in mixed venous blood?
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75%
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What is the saturation of O2 in arterial blood
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98%
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What is the PO2 of arterial and mixed venous blood?
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95 and 40
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What is the total oxygen content in ml/100ml of arterial and mixed venous blood
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20 and 15.2
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What are the dissolved O2 contents ml/100 ml in arterial and mixed venous blood
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0.3 and 0.1
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What are the bound O2 contents of arterial and mixed venous blood ml/100ml
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19.7 and 15.1
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What is arterial and mixed venous pco2
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40 and 45
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What is arterial and mixed venous dissolved co2/100 ml
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2.52 and 2.84
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What is the total CO2 ml/100 ml of arterial and mixed venous blood
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48 and 52
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Why does the arterial mixed venous o2 content difference exceed the CO2 content difference?
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This is due to our respiratory quotient being less than one (less than one molecule of CO2 produced per O2) since we use fats and carbs for energy. The respiratory quotient when only fats are used is 0.7; when only carbs are used it is 1. For us, it is in between the two.
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Why does arterial mixed venous PO2 difference approximate 60 while PCO2 difference approximates only 5?
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Differences of the dissociation curves at their applicable physiological range (also CO2 is carried as bicarbonate)
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How to increase blood delivery in a healthy person?
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Up blood flow. Up hemoglobin concentration.
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