brainstem or brain stem [breyn-stem] Word Origin noun
- the portion of the that is continuous with the spinal cord and comprises the medulla oblongata, pons, midbrain, and parts of the hypothalamus, functioning in the control of reflexes and such essential internal mechanisms as respiration and heartbeat.
Origin of brainstem First recorded in 1875–80;+ British Dictionary definitions for brain stem brainstem noun
- the stalklike part of the brain consisting of the medulla oblongata, the midbrain, and the pons Varolii
brain stem in Science brainstem [brān′stĕm′]
- 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.