Which structure relays impulses between brain and spinal cord?

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

Answer: (B)

The main idea is that the brainstem acts as the bridge for signals traveling between the brain and the spinal cord, and the medulla oblongata is the part of that bridge right at the level where spinal cord begins. It carries all the ascending sensory tracts and descending motor tracts that connect the brain with the spinal cord, making it the primary conduit for impulses traveling to and from the brain. It also houses vital autonomic centers, but its role as the direct relay station is the key point here. The thalamus focuses on relaying sensory information to the cerebral cortex within the brain, the cerebellum coordinates movement rather than serving as the main link to the spinal cord, and while the pons participates in relays within the brainstem, the medulla oblongata is the definitive structure that connects brain to spinal cord.