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.
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 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
The pons possesses a median raphe continuous with that of the medulla oblongata, and formed like it by a decussation of fibres in the mesial plane.
From Encyclopaedia Britannica, 11th Edition, Volume 4, Slice 4 "Bradford, William" to "Brequigny, Louis" by Various
An important vaso-motor centre for the brain vessels exists, possibly diffused through an area somewhere between the thalamus and subthalamic region above the pyramidal decussation below.
From Degeneracy Its Causes, Signs and Results by Talbot, Eugene S.
Summing up this description of the hereditary qualities of our twisted teasels and of their mechanical consequences, we may say that the loss of the normal decussation is the cause of all the observed changes.
From Species and Varieties, Their Origin by Mutation by Vries, Hugo de
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
