Final answer:
The dorsal respiratory group is active during inspiration, whereas the ventral respiratory group is active during both inspiration and expiration in forced breathing situations. The correct answer, closest to the options given, is A) Inspiration, expiration.
Step-by-step explanation:
The dorsal respiratory group (DRG) is primarily active during the process of inspiration when it stimulates the contraction of the diaphragm and intercostal muscles to induce air to enter the lungs. In contrast, the ventral respiratory group (VRG) is active during periods of heavy or forced breathing, both for inspiration and expiration. It triggers the contraction of accessory muscles involved in deep inhalation and the accessory muscles necessary for forced expiration.
Therefore, the answer is that the dorsal respiratory group is active during inspiration, and the ventral respiratory group is active during both inspiration and expiration when more effort is required, such as in exercise or respiratory distress. However, if we are to choose between the options provided, the closest accurate response would be: A) Inspiration, expiration.
The dorsal respiratory group (DRG) in the medulla oblongata is active during inspiration, while the ventral respiratory group (VRG) is active during forced inspiration and expiration.