The major stimulus for increased ventilation during exercise is:Group of answer choicesCO2 flux to the lungincreased blood lactatehypoxia

The major stimulus for increased ventilation during exercise is CO2 flux to the lung. Here's why:

1. During exercise, your muscles produce more carbon dioxide (CO2) as a byproduct of cellular respiration.

2. This increase in CO2 levels in the blood triggers chemoreceptors in the body, particularly in the medulla oblongata of the brain and in the aortic and carotid bodies in the blood vessels.

3. These chemoreceptors send signals to the respiratory center in the brain to increase the rate and depth of breathing. This process is known as chemoreceptor reflex.

4. As a result, ventilation increases, allowing more oxygen to be taken in and more CO2 to be expelled from the body.

5. This process helps to maintain the balance of gases in the blood and to ensure that the working muscles receive enough oxygen to continue functioning effectively.

While increased blood lactate and hypoxia can also stimulate increased ventilation, they are not the primary drivers. The body's response to CO2 levels is faster and more sensitive, making CO2 flux to the lung the major stimulus for increased ventilation during exercise.