Haemoglobin and Gas transport Flashcards
What does partial pressure of O2 refer to?
Purely to O2 in solution and is determined by O2 solubility and driving gas pp. (in this case alveolar O2)
What percentage of arterial O2 is extracted by peripheral tissues at rest?
25%
What is the determinate of how much Hb gets oxygenated(short term oxidation)?
Partial pressure
Define anaemia:
Any condition where the oxygen carrying capacity of the blood is compromised.
Examples of anaemia
- Iron Deficiency
- haemorrhage
- Vit B12 deficiency (used for RBC production)
How does anaemia affect arterial pressure
Normal despite the total blood content being low. There is no problem with ventilation and perfusion.
How do you shift the oxygen dissociation curve to the right?
Increased pH
Increase CO2
Increased temp
Release DPG
When is DPG released?
Produced by red blood cells in hypoxic conditions
How much greater is the affinity for CO than O2 with Hb?
x250 times greater
What are the symptoms of CO poisoning?
- Hypoxia
- Anaemia
- Nausea
- Cherry red skin+mucous membranes
What happens resp rate with CO poisoning?
Unaffected- as PaCO2 is normal.
What is the outcome of CO poising?
Pot brain damage or death.
Name the different types of hypoxia?
Hypoxic Hypoxia Anaemic Hypoxia Ischemic (stagnant) Hypoxia Histotoxic Hypoxia Metabolic Hypoxia
Describe Hypoxic hypoxia
Most common. Reduction in O2 diffusion at Lungs either due to decreased PO2 or tissue pathology.
Describe anaemic hypoxia
Reduction in O2 carrying capacity of blood due to anaemia (red blood cell loss/iron deficiency)
