Unit page, primary language: LA, subsidiary: EN, interface: EN, work in progress

decussatio pyramidum (par)

Official Latin term decussatio pyramidum (par)
Official subsidiary term decussation of pyramids (pair)
Unit identifier TAH:U5293
Unit type pair
Materiality material
Link to the unit decussatio pyramidum (par)
Links of entity generic: decussatio pyramidum
External links TA98
Partonomic links Level 2: tractus systematis nervosi centralis (par) Short Extended
Level 3: tractus originis telencephali (par) Short Extended
Level 4: tractus descendentes originis cerebri (par)
Taxonomic links Level 2: substantia alba systematis nervosi centralis Short Extended
Level 3: segmentum systematis nervosi centralis
Subsidiary language with Latin English French Spanish Russian
Non Latin primary language English French Spanish Russian
Taxonomic definition
Taxonomic definition A decussation of pyramids is a decussation of neuraxis [decussatio neuraxis ] which is found in the caudal rhombencephalon [rhombencephalon caudale ] where the fibers of the lateral corticospinal tract [tractus corticospinalis lateralis ] cross from the ipsilateral to the contralateral side of their origin.

About the term decussation.

The word decussation means crossing when speaking of fibrae or neural pathways of the neuraxis. A decussation occurs when the fibrae running on one side of the neuraxis move to the other side.

The side is determined relative to the origin of the fibrae. When speaking of the side of origin, the adjective ipsilateral is used. When speaking of the opposite side, the adjective contralateral is used.

A decussation is indeed a paired entity. It is made of a paired set of fibrae running on each side, which, at the point of decussation, cross the midline in a symmetric way, and then continue on the contralateral side. Consequently, there is a left and a right decussation representing each set of crossing fibers.

Date: 08.05.2022