oxygen and carbondioxide shii

• Outline


  • Attempt these
  • Introduction
  • Mechanisms of transport
  • Oxygen-hemoglobin dissociation curve
  • Application
  • Conclusion
  • References
  • Answers
• Most of the CO2 transported in the blood is in HCO3−
• The amount of hemoglobin in the blood has the greatest effect on the ability of blood to transport oxygen
• CO2 +H2O ⇆ H2CO3 ⇆ H+ + HCO3-


  1. Reaction 2 is catalyzed by carbonic anhydrase

  2. Because of reaction 2, the pH of blood declines during hyperventilation

  3. Reaction 1 occurs in the red blood cell without enzymatic involvement

  4. Reaction 1 occurs primarily in plasma

  5. The reactions move to the right when there is excess H+ in the tissues
• Pulse oximetry only tells you about hemoglobin's ability to saturate with oxygen and nothing about the quantity of red blood cells in the blood
• The oxygen content in the blood increases in anaemia to compensate for the loss of hemoglobin
• Acidosis is when arterial pH is below 7.40 and alkalosis is technically present whenever pH is above 7.40
• Bohr effect


  The decrease of hemoglobin's oxygen binding capacity with an increase in carbon dioxide concentration or a decrease in pH
• Haldane effect


  The decrease of hemoglobin's carbon dioxide binding capacity with an increase in oxygen concentration
• Deoxygenated hemoglobin has a higher affinity (~3.5 x) for CO2 than does oxyhemoglobin
• Chloride shift


  Exchange of Chloride ion for Bicarbonate ion to maintain electrical charge (neutrality) of the RBC by an anion transport protein at the tissues
• Addressing the underlying cause helps improve oxygenation in cyanosis
• Anemia with a decrease in the hemoglobin content lowers concentration of O2 only, while saturation of O2 remain normal (anemic hypoxemia)
• Tissue hypoxia usually leads to activation of compensatory mechanisms
• It is important to understand the different processes for delivering oxygen to tissues and carbondioxide to the lungs