brain stem or brainstem
The portion of the brain, consisting of the medulla oblongata, pons Varolii, and mesencephalon, that connects the spinal cord to the forebrain and cerebrum.
The part of the vertebrate brain located at the base of the brain and made up of the medulla oblongata, pons, and midbrain. The brainstem controls and regulates vital body functions, including respiration, heart rate, and blood pressure. See also reticular formation.