Which brain region contains the nuclei responsible for regulating autonomic functions such as respiration and heart rate?

• A. Pons
• B. Medulla oblongata
• C. Thalamus
• D. Cerebellum

Answer: (B)

Autonomic control of breathing and heart rate is handled by centers in the brainstem, with the medulla oblongata housing the primary nuclei for this regulation. The medulla contains the respiratory rhythmicity centers (the dorsal and ventral respiratory groups) that generate the breathing rhythm and adjust depth, and the cardiac center that modulates heart rate through autonomic outputs. It also integrates input from chemoreceptors and baroreceptors to respond to changes in CO2, O2, pH, and blood pressure. The pons can influence breathing patterns, but the essential automatic regulation of respiration and heart rate rests in the medulla. The thalamus and cerebellum are involved in sensory relay and motor coordination, not the core autonomic control of these functions.