The VRG is known to contain which types of neurons?

• A. Only inspiratory neurons
• B. Only expiratory neurons
• C. Both inspiratory and expiratory neurons
• D. Only sensory neurons

Answer: (C)

The ventral respiratory group (VRG) is an essential component of the respiratory centers located in the medulla oblongata. It plays a crucial role in regulating breathing patterns. The VRG contains both inspiratory and expiratory neurons, which coordinate the phases of breathing.

Inspiratory neurons within the VRG are responsible for initiating inhalation by stimulating the diaphragm and external intercostal muscles, promoting lung expansion. Conversely, expiratory neurons help facilitate expiration by signaling the muscles involved in exhalation, particularly during forceful breathing, such as during exercise or respiratory distress.

The dual functionality of both inspiratory and expiratory neurons allows the VRG to adaptively regulate ventilation based on the body's varying demands for oxygen and the removal of carbon dioxide. This integrated approach ensures that the respiratory rhythm is responsive to metabolic needs, making the VRG a crucial center for maintaining homeostasis in respiratory function.