Basic and Clinical Sciences (BCSE) 2025 – 400 Free Practice Questions to Pass the Exam

The dorsal respiratory group (DRG) is primarily responsible for influencing the rhythm and depth of breathing. It plays a crucial role in regulating the automatic rhythm of respiration by sending signals that stimulate inhalation. This group of neurons is located in the medulla oblongata and is primarily active during quiet, restful breathing.

As a main regulator of respiration, the DRG integrates sensory information regarding blood gas levels (oxygen and carbon dioxide) and adjusts breathing patterns to maintain homeostasis. It activates the diaphragm and intercostal muscles, thus facilitating inspiration.

The other choices, while related to respiratory functions, do not accurately describe the primary role of the DRG. Increased pulmonary ventilation and increased respiratory rate would involve both the DRG and additional regulatory centers. Additionally, limiting inspiration is governed by other mechanisms that help modulate breathing rate rather than being a primary function of the DRG itself. Inhibiting respiratory activity during rest is not consistent with the DRG’s function, as it primarily promotes inhalation. Thus, identifying the DRG as the main regulator of respiration aligns with its established role in the respiratory control system.