When you hold your breath, which of the following gas changes in blood would first lead to the urge to breathe?

Question

When you hold your breath, which of the following gas changes in blood would first lead to the urge to breathe? (A) Falling CO2 concentration (B) Rising CO2 and falling O2 concentration (C) Falling O2 concentration (D) Rising CO2 concentration

Tardigrade Admin · Accepted Answer

Excess CO2 mainly stimulates the respiratory centre of the brain and increases the inspiratory and expiratory signals to the respiratory muscles. O2 does not have a significant direct effect on the respiratory centre of the brain in controlling respiration.

Q. When you hold your breath, which of the following gas changes in blood would first lead to the urge to breathe?

Falling CO₂ concentration

Rising CO₂ and falling O₂ concentration

Falling O₂ concentration

Rising CO₂ concentration

Excess CO₂ mainly stimulates the respiratory centre of the brain and increases the inspiratory and expiratory signals to the respiratory muscles. O₂ does not have a significant direct effect on the respiratory centre of the brain in controlling respiration.