extrapyramidal motor system


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Related to extrapyramidal motor system: Extrapyramidal tracts

ex·tra·py·ram·i·dal mo·tor sys·tem

literally, all brain structures that affect bodily (somatic) movement, excluding the motor neurons, the motor cortex, and the pyramidal (corticobulbar and corticospinal) tract. Despite its very wide literal connotation, the term is more often used to denote in particular the striate body (basal ganglia), its associated structures (substantia nigra, subthalamic nucleus), and its descending connections with the midbrain.

ex·tra·py·ram·i·dal mo·tor sys·tem

(eks'tră-pir-am'i-dăl mō'tŏr sis'tĕm)
Literally: all those brain structures affecting bodily (somatic) movement, excluding the motor neurons, the motor cortex, and the pyramidal (corticobulbar and corticospinal) tract. Despite its very wide literal connotation, the term is commonly used to denote in particular the striate body (basal ganglia), its associated structures (substantia nigra, subthalamic nucleus), and its descending connections with the midbrain.

extrapyramidal

outside the pyramidal tracts.

extrapyramidal disease, extrapyramidal syndrome
any of a group of clinical disorders marked by abnormal involuntary movements, alterations in muscle tone, and postural disturbances.
extrapyramidal motor system
see extrapyramidal system (below).
extrapyramidal system
a functional, rather than anatomical, unit comprising the nuclei and fibers (excluding those of the pyramidal tract) involved in motor activities; they control and coordinate especially the postural, static, supporting and locomotor mechanisms. It includes the corpus striatum, subthalamic nucleus, substantia nigra and red nucleus, along with their interconnections with the reticular formation, cerebellum and cerebrum; some authorities include the cerebellum and vestibular nuclei. Called also extrapyramidal motor system.
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