pyramidal decussation

(redirected from decussatio pyramidum)

py·ram·i·dal de·cus·sa·tion

(pir-am'i-dăl dē'kŭs-ā'shŭn)
The intercrossing of the bundles of the pyramidal tracts at the lower border region of the medulla oblongata.
Synonym(s): decussatio pyramidum [TA] , motor decussation.

pyramidal decussation

The crossing of 90% of the axons of the corticospinal tracts (the pyramidal tracts) in the ventral region of the caudal hindbrain. On the contralateral side, the crossed axons interdigitate with 10% of the corticospinal axons that have not crossed, and the full complement of axons continues into the spinal cord in the lateral funiculus.
Synonym: decussation of the pyramids
See also: decussation