pineal peduncle


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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.

pineal peduncle

Etymology: L, pineus, pine cone, peduncle, small foot
the stalk of the pineal body.

pineal peduncle

A band from either side of the pineal gland to the anterior pillars of the fornix at the back of the roof of the third ventricle. The pineal recess is a space nestled into the peduncle. Synonym: pineal stalk
See also: peduncle

peduncle

a stemlike connecting part, especially: (1) a collection of nerve fibers coursing between different regions in the central nervous system, or (2) the stalk by which a nonsessile tumor is attached to normal tissue.

cerebellar p's
three pairs of thick, white fiber trunks that arise from the midbrain, pons and medulla and pass into the cerebellum.
cerebral peduncle
the ventral half of the midbrain, divisible into a dorsal part (tegmentum) and a ventral part (crus cerebri), which are separated by the substantia nigra.
peduncle disease
a disease of marine fish caused by the flexibacter Cytophaga psychrophila.
olfactory peduncle
caudal continuation of the olfactory bulb of the brain.
pineal peduncle
see habenula (2).