decussation
Americannoun
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a process of becoming or condition of being crossed in the form of an X .
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Anatomy. a nerve or tract of nerve fibers that crosses from one side of the central nervous system to the other.
Etymology
Origin of decussation
Explanation
When two things cross and form the shape of an X, that's decussation. Nature has many examples of decussation, from patterns in leaves to nerve fibers in the human body. Decussation is a technical term for something that happens all the time in the natural world. In our brains, for example, there is a type of decussation where nerve fibers cross from one hemisphere to the other. Botanists describe the decussation of leaves on a plant when they cross each other in patterns that form right angles. The Latin source is decussis, "the figure or shape of ten," or in Roman numerals, X.
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
The defining landmark of the medullary- spinal border is the pyramidal decussation, which is where most of the fibers in the corticospinal tract cross over to the opposite side of the brain.
From Textbooks ● Jun. 19, 2013
In the dorsal column system, this decussation takes place in the brain stem; in the spinothalamic pathway, it takes place in the spinal cord at the same spinal cord level at which the information entered.
From Textbooks ● Jun. 19, 2013
The fine ribs that cross the whorls are not present on the wings, nor on the back; they are nodulated at their decussation with the raised striae.
The most anterior is the pyramid or motor tract, the decussation of which has been seen.
From Encyclopaedia Britannica, 11th Edition, Volume 4, Slice 4 "Bradford, William" to "Brequigny, Louis" by Various
Thus, Mr. Clarke's dissections, confirmed by preparations of Mr. Dean's which I have myself examined, placed the fact of the decussation of the pyramids—denied by Haller, by Morgagni, and even by Stilling—beyond doubt.
From Medical Essays, 1842-1882 by Oliver Wendell Holmes
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