brain stem
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stem
[stem]a stalklike supporting structure; see also peduncle.
brain stem brainstem.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.
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]
Farlex Partner Medical Dictionary © Farlex 2012
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.
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.
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.
Medical Dictionary for the Health Professions and Nursing © Farlex 2012
brain stem
that part of the brain in vertebrates which excludes the CEREBELLUM and CEREBRAL HEMISPHERES.Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005
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.
Medical Dictionary for the Dental Professions © Farlex 2012