Extrapyramidal system

That part of the nervous system that regulates muscle reflexes.

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the system of nerve tracts and pathways connecting the cerebral cortex, basal ganglia, thalamus, cerebellum, reticular formation, and spinal neurones in complex circuits not included in the pyramidal system. The extrapyramidal system is mainly concerned with the regulation of stereotyped reflex muscular movements.

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an imprecise term referring to a functional rather than an anatomical part of the central nervous system that controls motor activities and is not part of the pyramidal tract; it includes the corpus striatum, subthalamic nucleus, substantia nigra, and red nucleus along with their interconnections with the reticular formation, cerebrum, and cerebellum; they control and coordinate especially the postural, static, supporting, and locomotor mechanisms. Since the term is imprecise and applies literally to all structures outside the corticospinal system, it has largely fallen into disuse. Called also extracorticospinal s. or tract and extrapyramidal tract.