Which brainstem structure controls breathing and heart rate?

• A. Pons
• B. Cortex
• C. Thalamus
• D. Medulla Oblongata

Answer: (D)

Breathing and heart rate are controlled by central autonomic centers in the brainstem, with the medulla oblongata providing the core regulation. It houses the primary rhythm-generating and regulatory centers for respiration—the dorsal respiratory group sets the basic inspiratory rhythm, and the ventral respiratory group assists with expiration during active/demanding breathing. The medulla also contains the cardioinhibitory center, which slows heart rate via the vagus nerve, and the vasomotor center, which adjusts vascular tone through sympathetic outputs. It receives input from chemoreceptors and baroreceptors to fine-tune both breathing and heart rate as needed. While higher brain regions and the pons can modulate breathing, the medulla is the key structure that directly controls these vital functions.