Final answer:
The ventral respiratory group (VRG) in the medulla oblongata controls the muscles involved in forced breathing, ultimately playing a key role in controlling and regulating pulmonary ventilation during strenuous activity.
Step-by-step explanation:
The function of the ventral respiratory group (VRG) is primarily to control the muscles of respiration, specifically during periods of increased demand such as during forced breathing. It is responsible for stimulating the accessory muscles required for forced inspiration and expiration, making option 3) Controlling the muscles of respiration the correct answer.
The VRG sets the breathing rhythm under stress and integrates input from peripheral stretch receptors and chemoreceptors. While it does influence functions that can involve blood pressure and heart rate through the respiratory cycle, it is not directly responsible for regulating blood pressure or controlling heart rate. Additionally, the VRG does not maintain body temperature.
In conclusion, the medulla oblongata’s VRG is crucial for controlling and regulating pulmonary ventilation by stimulating the accessory muscles involved in forced respiration.