which portion of the brain contains the midbrain, pons, and medulla oblongata
The brain stem is the bottom-most portion of the brain, connecting the cerebrum with the spinal cord. The midbrain, pons, medulla oblongata, and reticular formation are all part of the brain stem. The midbrain is the short portion of the brain stem between the pons and the cerebral hemispheres. The top of the midbrain is called the tectum (or tectal area). The third and fourth cranial nerves originate in the midbrain.