Question

Explain SOME physiological mechanisms that could allow breath-hold divers to tolerate high levels of CO2 in their blood

Answer 1

Physiological mechanism that could allow breath-hold diver to toerate high levels of CO2 in their blood :

- Divers are trained to perform at high CO2 levels by exposing them repeatedly to high CO2 concentration. This leads to blunted ventilatory drive response to CO2.

- Diving response including peripheral vasoconstriction, increased arterial blood pressure, bradycardia and lowered cardiac output.

- Some peripheral regions may be excluded from perfusion, with consequent reliance on anaerobic metabolism.

- Extreme breath-hold divers show a blunted ventilatory response to carbon dioxide as a consequence of frequent exposure to high carbon dioxide partial pressures during the dives.

- This allow to breath hold diver to tolerate low alveolar oxygen and high alveolar carbon dioxide partial pressures and reduce oxygen consumption during the dive at the expense of increased anaerobic glycolysis.