brainstem

American  

[breyn-stem] / ˈbreɪnˌstɛm /

Or brain stem

noun

1. the portion of the brain 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.

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brainstem British  

/ ˈbreɪnˌstɛm /

noun

1. the stalklike part of the brain consisting of the medulla oblongata, the midbrain, and the pons Varolii

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brainstem Scientific  

/ brān′stĕm′ /

1. 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.

2. See also reticular formation

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Etymology

Origin of brainstem

First recorded in 1875–80; brain + stem ¹

Example Sentences

The locus coeruleus, found in the brainstem, helps regulate this process through long nerve fibers that extend to the olfactory bulb.

From Science Daily • Apr. 11, 2026

This area of the brainstem receives interoceptive input, or signals from the body about its internal state, like hunger, pain and fullness.

From Salon • Feb. 6, 2025

The researchers assumed the brain's frontal cortex, which orchestrates complex thoughts and behaviors, was somehow communicating to a brainstem region called the medulla, which controls automatic breathing.

From Science Daily • Nov. 19, 2024

Axial symptoms, which have not received extensive study in relation to DBS, improved with stimulation of tracts connected to the supplementary motor cortex and brainstem.

From Science Daily • Jun. 4, 2024

Capping the brainstem is the R-complex, the seat of aggression, ritual, territoriality and social hierarchy, which evolved hundreds of millions of years ago in our reptilian ancestors.

From "Cosmos" by Carl Sagan