Name the three parts of the brain stem.

• A. Cerebellum, Thalamus, Hypothalamus
• B. Cortex, Basal Ganglia, Hippocampus
• C. Optic Nerve, Spinal Cord, Cerebellum
• D. Midbrain, Pons, Medulla Oblongata

Answer: (D)

At the base of the brain, the brain stem is made up of three parts: the midbrain, the pons, and the medulla oblongata. These structures form the main conduit between the brain and the spinal cord and govern essential life-support functions. The midbrain sits above the pons and handles basic sensory and motor processes, including certain visual and auditory reflexes. The pons serves as a relay station, transmitting information between the cerebrum, cerebellum, and spinal cord, and it contributes to breathing regulation. The medulla oblongata lies lowest and controls autonomic functions such as heart rate, breathing, blood pressure, and reflexes like swallowing and coughing. Because these three regions—the midbrain, pons, and medulla oblongata—together constitute the brain stem, they are the correct answer. The other groups are not brain stem parts: they include higher brain regions or components outside the brain stem.