Where Does Decussation Occur

The sensory decussation or decussation of the lemnisci is a decussation or crossover of axons from the gracile nucleus and cuneate nucleus which are responsible for fine touch proprioception and two point discrimination of the body. Similarly the anatomical term chiasma is named after the greek uppercase χ chi.

Decussation An Overview Sciencedirect Topics

Decussation crossing of nerve fibres passing through the mid sagittal plane of the central nervous system and connecting with structures on the opposite side.

Where does decussation occur. In latin anatomical terms the form decussatio is used e g. Where does decussation occur in the trigeminothalamic pathway. Called also decussation of the pyramids.

Medical definition of pyramidal decussation. Decussation occur when fibers cross from one side of a structure to the other. The fibres of this decussation are called the internal arcuate fibres and are found at the superior aspect of the closed medulla superior to the motor decussation.

Partial decussation occurs at the optic chiasma. A brain decussation is a phenomenon in which the nerve fibers found in one lateral portion of the organ cross another. This decussation of the pyramidal tract is the reason that brain injuries and strokes on one side of the head typically cause paralysis on the other side of the body.

It is called the somatic twist hypothesis i and it asserts that neural crossings technically called decussations are the byproduct of a much larger evolutionary change the switch from having a ventral belly side nerve cord to dorsal back side nerve cord. The status known as pyramidal decussation has to do with the passage of motor fibers from the brain to medulla spinalis and medulla oblongata. For instant motor fibers that travel in the corticospinal tract originate in the cerebral cortex and move down to the body.

The crossing of the fibers of the corticospinal tracts from one side of the central nervous system to the other near the junction of the medulla and the spinal cord. Pons or medulla 2 possible pathways where does decussation occur in the lateral corticospinal pathway. It is part of the second neuron in the posterior column medial lemniscus pathway.

Dictionary of optometry and visual science 7th edition. My favorite theory though has to do with the evolution of the entire vertebrate lineage. This crossover or decussation occurs just before the junction between the medulla oblongata and the spinal cord.

Decussation is used in biological contexts to describe a crossing in latin the roman numeral for ten deca is an uppercase x. Decussation definition is the action of crossing as of nerve fibers especially in the form of an x. Whereas a decussation refers to a crossing within the central nervous system various kinds of crossings in the peripheral nervous system are called chiasma.

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