This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Physiology
[{'content': 'Pre Botzinger complex is a part of : \nSelect and explain. \nA. VRG, B. DRG, C. Both, D. None', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Dorsal and ventral groups of respiratory neurons (DRG and VRG) are present in the medulla. However,\xa0 lesions of these neurons do not abolish respiratory activity, and they apparently project to the pre- Botzinger pacemaker neurons.\u200b\n\u200bDRG contains mainly I (inspiratory neurons) neurons and is part of the nucleus of the solitary tract\xa0 (or nucleus tractus solitarius, NTS).\u200b\nThe aﬀerent input from arterial chemoreceptors and lung mechanoreceptor synapses on neurons\xa0 in the NTS near the DRG. So, major function of DRG is integration of sensory information from respiratory system. \u200b\nVRG is a column of neurons that ﬁre action potentials in phase with respiration. It includes neurons depolarizing during inspiration (I neurons) and expiration (E neurons). All of these respiratory centers are bilaterally symmetrical on the right and left sides of the\xa0 brainstem.\u200b\nVRG contains three regions that performs speciﬁc functions: \u200b\n\nRostral VRG: Known as Botzinger complex: Expiratory neurons.\u200b\nIntermediate VRG: Pre-Botzinger complex: Inspiratory neurons generate respiratory rhythm. \u200b\nCaudal VRG: Expiratory neurons\u200b.\n\nSo, pre-Botzinger complex is a part of VRG.\nReference: Ganong’s Review of Medical Physiology 25 Ed page no 656\u200b', 'role': 'assistant'}]