superior cerebellar peduncle

superior cerebellar peduncle

n.

A large bundle of nerve fibers that originates from the dentate nucleus of the cerebellum and emerges from the cerebellum along the lateral wall of the fourth ventricle.

---

peduncle [pe-dung´k'l]

1. a stemlike connecting part.

2. a collection of nerve fibers connecting between different regions in the central nervous system.

3. the stalk by which a nonsessile tumor is attached to normal tissue. adj., adj pedun´cular.

cerebellar p's three sets of paired bundles (superior, middle, and inferior) connecting the cerebellum to the midbrain, pons, and medulla oblongata, respectively.

cerebral peduncle the anterior half of the midbrain, divisible into a posterior part (tegmentum) and an anterior part (crus cerebri), which are separated by the substantia nigra.

inferior cerebellar peduncle a large bundle of nerve fibers serving to connect the medulla oblongata and spinal cord with the cerebellum (especially the archicerebellum and paleocerebellum); it courses along the lateral border of the fourth ventricle and turns dorsally into the cerebellum. Formerly called caudal cerebellar peduncle.

middle cerebellar peduncle a large bundle of projection fibers originating in the contralateral pontine nuclei and entering the cerebellum, conveying impulses from the cerebral cortex to the neocerebellum.

pineal peduncle habenula (def. 2).

superior cerebellar peduncle a large bundle of projection fibers arising chiefly in the dentate nucleus of each cerebellar hemisphere (neocerebellum) and ascending to decussate in the mesencephalon; its fibers end mostly in the red nucleus and thalamus. Spinocerebellar fibers to the paleocerebellum lie adjacent to each peduncle. Formerly called rostral cerebellar peduncle.

p's of thalamus the four two-way radiations of thalamocortical fibers that connect the dorsal thalamus with many parts of the cerebral cortex, which together form a major portion of the internal capsule and the corona radiata.