Oxygen transport

Haemoglobin, the dissociation curve, the Bohr effect and the arteriovenous difference in exercise.

The outline, topic by topic

Each topic is weighted the way the exam weighs it.

Haemoglobin: what is it?
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The red-cell protein carrying about 98 % of the blood's oxygen.
One gram binds about 1.34 mL of O2.
Why does the S shape of the curve help exercise?
- A small fall in muscle PO2 releases much oxygen
- A large fall in PO2 is needed to release a little oxygen
- It increases the oxygen dissolved in plasma
- It makes haemoglobin bind more oxygen in muscle than in the lungs
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A small fall in muscle PO2 releases much oxygen
The steep part of the curve matches active tissues.
Dissociation curve: what is it?
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Haemoglobin saturation against O2 partial pressure, S-shaped.
The plateau protects O2 loading in the lungs.