Answer: vital capacity.
- A vital capacity
- B tidal volume
- C residual volume
- D anatomical dead space
Correct answer: A. vital capacity
Explanation: Vital capacity is the greatest volume that can be exhaled after a full inhalation.
The S-shaped (sigmoid) curve reflects cooperative binding between Hb's four O₂ sites; the Bohr effect shifts the whole curve to the right under conditions found in actively respiring tissue (more CO₂, more acid, more heat), making haemoglobin release oxygen more readily exactly where it's needed.
Concept context
The mechanics of breathing, lung volumes, gas transport in blood, the Bohr effect, and respiratory regulation.