Which part of the brainstem contains the respiratory and cardiovascular centers and relays signals between the brain and spinal cord?

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

Answer: (D)

The key idea is that autonomic control of breathing and heart activity is located in the medulla oblongata, the lower part of the brainstem. In this region lie the respiratory centers—the dorsal and ventral respiratory groups—that generate and adjust breathing rhythm, and the cardiovascular centers that regulate heart rate, the strength of contraction, and blood vessel diameter. The medulla also serves as a major relay between the brain and spinal cord, with critical pathways carrying motor and sensory information up and down the nervous system and cranial nerve nuclei that connect to autonomic outputs. While the pons helps modulate breathing, it does not house the primary centers; the midbrain and cerebellum are not where these autonomic controls reside.