brain stem


Also found in: Dictionary, Thesaurus, Legal, Acronyms, Encyclopedia, Wikipedia.
Related to brain stem: brain stem reflexes

stem

 [stem]
a stalklike supporting structure; see also peduncle.
brain stem brainstem.

brain·stem

, brain stem (brān'stem), [TA]
Originally, the entire unpaired subdivision of the brain, composed of (in anterior sequence) the rhombencephalon, mesencephalon, and diencephalon as distinguished from the brain's only paired subdivision, the telencephalon. More recently, the term's connotation has undergone several arbitrary modifications: some use it to denote no more than rhombencephalon plus mesencephalon, distinguishing that complex from the prosencephalon (diencephalon plus telencephalon); others restrict it even further to refer exclusively to the rhombencephalon. From both developmental and architectural viewpoints, the original interpretation seems preferable.
Synonym(s): truncus encephali [TA]

brainstem

The central stalk-like axis of the lower CNS, which connects the brain with the spinal cord.
 
Components
• Medulla oblongata;
• Pons;
• Midbrain;
• Diencephalon.
 
Functions
• Transmission and “lower cortical” processing of sensory neural impulses from the periphery and motor impulses to muscles and other effectors;
• Anatomic site of egress of cranial nerves 3 to 12;
• Reticular functions, integrating cardiorespiratory control, arousal and alertness, consciousness.

brain·stem

, brain stem (brān'stem) [TA]
Originally, the entire unpaired subdivision of the brain, composed of the rhombencephalon, mesencephalon, and diencephalon as distinguished from the brain's only paired subdivision, the telencephalon. More recently, the connotation of the term has undergone several arbitrary modifications: some use it to denote no more than rhombencephalon plus mesencephalon, distinguishing that complex from the prosencephalon (diencephalon plus telencephalon); others restrict it even further to refer exclusively to the rhombencephalon. From both developmental and architectural viewpoints, the original interpretation seems preferable.

brain stem

that part of the brain in vertebrates which excludes the CEREBELLUM and CEREBRAL HEMISPHERES.

brain·stem

, brain stem (brān'stem) [TA]
Originally, the entire unpaired subdivision of the brain, composed of the rhombencephalon, mesencephalon, and diencephalon as distinguished from the brain's only paired subdivision, the telencephalon. More recently, the connotation of the term has undergone several arbitrary modifications: some use it to denote no more than rhombencephalon plus mesencephalon, distinguishing that complex from the prosencephalon (diencephalon plus telencephalon); others restrict it even further to refer exclusively to the rhombencephalon. From both developmental and architectural viewpoints, the original interpretation seems preferable.

stem

stalk; a stalklike supporting structure.

brain stem
References in periodicals archive ?
Findings in Diffuse Axonal Injury: Brain edema 5 cases Petechial bleeds in the grey white junction 4 cases Brain stem bleed posterior aspect 3 case
Although doctors are good at talking about brain stem death, some may be uncomfortable with talking about donation,' she said.
During the experiments, Gwendolyn Binder, a graduate student, observed that, using interferon-[gamma], CD4 and CD8 T-cells both successfully cleared the virus in the neurons from the spinal cord and brain stem.
Many of these individuals retain clear evidence of integrated brain function at the level of the brain stem and mid-brain, and may have evidence of cortical functioning.
Almost three years ago, Tom discovered he had a tumour growing near his brain stem.
It showed that the vets had lost 10% to 25% of their brain cells in three areas: the basal ganglia on both sides of the brain and the brain stem.
Rick had suffered a brain stem injury that completely paralyzed him initially.
Jill Yaz, from the Association for ina Bifida and Hydrocephalus HINE), said: "The brain stem controls the basic functions that we need to survive - the heart, breathing and organs like the intestines.
It is understood the sixday-old baby in London was able to become a donor because she died from cardiac failure, and issues of how to declare a baby brain stem dead were not relevant.
The Redcar five-year-old is recovering after treatment to battle a recurring brain stem tumour.
Auditory brain stem response (ABR) is a non-invasive method of recording electrical activity of the brain stem in response to sound stimulus.