Question

34. If we injected lactic acid into the bloodstream of a resting individual,

    1. Ventilation would increase

    2. Ventilation would decrease

    3. Ventilation would not change

Answer 1

Answer:

ventilation would increase

explanation: Injectionof lactic acid in the blood results in decrease of pH of the blood. This stimulates the respiratory center to increase the ventilation so that excessive carboon dioxide could be washed out of the body through lungs to prevent formation of new H+ ions. We know that CO2 combines with H2O which forms H2CO3 which dissociate to yield H+ ions that decreases the pH. Hence Excessive wash out of CO2 by incrasing the ventilation will prevent the formation of H+ ions and hence pH return back to normal.