Oxygen in the Blood Flashcards
What is the maximum cardiac output?
25 L per min
How many O2 molecules can haemoglobin carry?
4
Why is saturation expressed as a %?
So that oxygen binding is independent from pigment concentration
What subunits form a haemoglobin?
2 alpha and 2 beta subunits
What are the 2 “moods” of haemoglobin?
Low affinity for oxygen “tense” state, High affinity for oxygen “relaxed” state
What Partial pressure of oxygen does haemoglobin saturate at?
9-10kPa
What is a normal oxygen content of the blood?
8.8 mm per L
How low can a tissue p02 fall?
Most tissues not below 3kPa
What is the Bohr shift?
When acidic conditions shifts the dissociation curve to the right so that more oxygen is given up to the tissue. (temperature also does this)
How much can metabolism increase by?
Up to 10 x during extreme exercise
What does 2,3-Bisphosphoglycerate do
Shifts the dissociation curve to the right so that more oxygen is given up to the tissues
What does CO do to Hb molecules?
irreversibly binds preventing the binding of oxygen and also prevents Hb releasing oxygen to the tissues
What is hypoxemia?
low p02 in the arterial blood
How does pule oximetry work?
Detects the levels of Hb saturation in pulsatile arterial blood using red and infrared light
