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5 Cards in this Set
- Front
- Back
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Describe the means by which oxygen is dissolved in the blood (2 basic ways) |
Dissolved in blood (1.5%)O2 has low solubility compared to CO2O2 carrying capacity in plasma = 0.3 ml O2/dL bloodBound to haemoglobin RBC (98.5%)[Hb] = 15g /dL |
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Haemoglobin Structure in adults and fetal types |
Haem - Fe2+ containing moleculeGlobin – 4 polypeptide chainsAdult Hb A – 2α & 2β chain Fetus Hb F– 2α & 2y (gamma) chains 2 states - oxyhaemoglobin & deoxyhaemoglobin |
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Terminology relating to O2 absorption 1. O2 pressure (PaO2) 2. O2 capacity 3. O2 content (CaO2) 4. O2 saturation |
1. O2 pressure (PaO2) Amount of oxygen dissolved in plasma = 0.3 ml/dL 2. O2 capacity = Amount of O2 bound to Hb 15 g/dL x 1.34 ml O2 (x % saturation)= 19.7 ml O2/dL 3. O2 content (CaO2) Amount of O2 bound to Hb + dissolved O219.7 ml O2/dL (x % saturation) + 0.3 ml O2/dL= 20 ml/dL 4. O2 saturation The % of available binding sites bound to O2 . This stays constant with the PaO2. |
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O2 binding equation |
O2 + deoxyhaemoglobin (Fe 2+) <--> oxyhaemoglobin |
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What is Methaemoglobin? Methemoglobinemia signs, symptoms |
Methaemoglobin - haemoglobin in ferric state (Fe3+)Methaemoglobin reductase re |
