chiasma
noun
a crossing or decussation, as that of the optic nerves at the base of the brain.
chiasm
-
a variation of
chiasma.
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.
Hazel has an optic chiasm pilocytic astrocytoma - a slow-growing tumour which presses on her optic nerve and affects her vision.
From BBC ● Jan. 19, 2026
The same axons extend from the eye to the brain through these two bundles of fibers, but the chiasm represents the border between peripheral and central.
From Textbooks ● Jun. 19, 2013
The pituitary, seated in the sella turcica of the sphenoid bone, is directly inferior to the optic chiasm.
From Textbooks ● Jun. 19, 2013
If the pituitary gland develops a tumor, it can press against the fibers crossing in the chiasm.
From Textbooks ● Jun. 19, 2013
Extending from the optic chiasm, the axons of the visual system are referred to as the optic tract instead of the optic nerve.
From Textbooks ● Jun. 19, 2013
