Oxygen Carriage Flashcards
What determines PaO2?
O2 solubility, and PO2 in the gaseous phase (that drives O2 into solution).
What does PO2 determine?
The total O2 content of the blood, by determining Hb saturation.
PO2 = PaO2.
How do gases travel in plasma?
In solution.
Gaseous bubbles in blood would cause a fatal air embolism.
What are the types of haemoglobin?
In the blood:
92% - HbA.
8% - HbA2, HbF, glycosylated Hb.
In cardiac and skeletal muscle:
Myoglobin.
How are HbF and myoglobin adapted for their function?
They have a higher affinity for O2 than HbA.
Allows extraction of O2 from maternal / arterial blood.
What is hypoxaemic hypoxia?
The most common.
A reduction in O2 diffusion at the lungs, due to a decreased atmospheric PO2, or tissue pathology.
What is anaemic hypoxia?
A reduction in O2 carrying capacity of blood, due to anaemia.
What is stagnant hypoxia?
Heart disease results in inefficient pumping of the blood to the lungs / around the body.
What is histotoxic hypoxia?
Poisoning prevents cells using O2 delivered to them (Ex. CO, cyanide).
What is metabolic hypoxia?
O2 delivery to the tissues does not meet an increased oxygen demand by the cells.
