pyramidal decussation

decussation /de·cus·sa·tion/ (-sa´shun) a crossing over; the intercrossing of fellow parts or structures in the form of an X.

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Forel's decussation  the ventral tegmental decussation of the rubrospinal and rubroreticular tracts in the mesencephalon.

fountain decussation of Meynert  the dorsal tegmental decussation of the tectospinal tract in the mesencephalon.

pyramidal decussation  the anterior part of the lower medulla oblongata in which most of the fibers of the pyramids intersect.

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pyramidal decussation

n.

Crossing of the bundles of the pyramidal tracts at the lower border of the medulla oblongata. Also called motor decussation.