Which brainstem region is the most caudal and marks the transition from brainstem to spinal cord?

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

Answer: (A)

The boundary between the brainstem and the spinal cord is at the medulla oblongata, the most caudal part of the brainstem. It sits just above the foramen magnum, where the spinal cord begins as it exits the skull. This makes the medulla the last brainstem segment and the point where brainstem functions transition to spinal cord pathways. The other regions lie rostrally (earlier along the brainstem) or, in the case of the cerebellum, are not part of the brainstem itself. The medulla also houses important fiber tracts and cranial nerve nuclei, underscoring its role as the gateway between brainstem control and spinal cord transmission.