chiasma
Anatomy. a crossing or decussation, as that of the optic nerves at the base of the brain.
Cell Biology. a point of overlap of paired chromatids at which fusion and exchange of genetic material take place during prophase of meiosis.
Origin of chiasma
1- Also chi·asm [kahy-az-uhm]. /ˈkaɪ æz əm/.
Other words from chiasma
- chi·as·mal, chi·as·mic, chi·as·mat·ic [kahy-az-mat-ik], /ˌkaɪ æzˈmæt ɪk/, adjective
Words Nearby chiasma
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2024
How to use chiasma in a sentence
We know that they are directly connected by fibres that arch round through the chiasma.
Medical Essays | Oliver Wendell Holmes, Sr.Pressure on the optic chiasma, for example by a tumour of the pituitary body, is associated with bilateral temporal hemianopsia.
Manual of Surgery Volume Second: Extremities--Head--Neck. Sixth Edition. | Alexander MilesAt the base of the section are seen the optic nerves and their chiasma.
The Works of Francis Maitland Balfour, Volume IV (of 4) | Francis Maitland BalfourThe optic chiasma, where present, is involved in the floor of the thalamencephalon and forms a large, upwardly-projecting ridge.
The nerves are fibrous, and a commencement of the chiasma is certainly present.
The Works of Francis Maitland Balfour, Volume 1 | Francis Maitland Balfour
British Dictionary definitions for chiasma
chiasm (ˈkaɪæzəm)
/ (kaɪˈæzmə) /
cytology the cross-shaped connection produced by the crossing over of pairing chromosomes during meiosis
anatomy the crossing over of two parts or structures, such as the fibres of the optic nerves in the brain
Origin of chiasma
1Derived forms of chiasma
- chiasmal or chiasmic, adjective
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Browse