A 3D medical animation still shot showing different parts of the midbrain. The brainstem (or brain stem) is the posterior stalk-like part of the brain that connects the cerebrum with the spinal cord.[1] In the human brain the brainstem is composed of the midbrain, the pons, and the medulla oblongata.[1] The midbrain is continuous with the thalamus of the diencephalon through the tentorial notch, a