Decussation
（重定向自Decussatio）
![Section of the medulla oblongata at the level of the decussation of the pyramids.](/Images/godic/202501/08/Gray6881531.png")
![Decussate phyllotaxis of Crassula rupestris](/Images/godic/202501/08/Crassula_rupestris-PICT30871531.jpg")
Decussation is used in biological contexts to describe a crossing. (In Latin anatomical terms the form decussatio is used, e.g. decussatio pyramidum.) In anatomy the term chiasma or chiasm means nearly the same as decussation.
Examples include: