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Citation, DOI & article dataCitation: Gaillard F, Hacking C, Gajera J, et al. Corpus callosum. Reference article, Radiopaedia.org (Accessed on 11 Dec 2022) https://doi.org/10.53347/rID-4672 The corpus callosum (plural: corpora callosa) is the largest of the commissural fibers, linking the cerebral cortex of the left and right cerebral hemispheres. It is the largest white matter tract in the brain. On this page:
The corpus callosum is approximately 10 cm in length and is C-shaped (like most supratentorial structures) in a gentle upwardly convex arch. It is thicker posteriorly. It is divided into four parts (from anterior to posterior):
RelationsImmediately above the body of the corpus callosum, lies the interhemispheric fissure in which runs the falx cerebri and branches of the anterior cerebral vessels. The superior surface of the corpus callosum is covered by a thin layer of grey matter known as the indusium griseum. On either side, the body is separated from the cingulate gyrus by the callosal sulcus. Attached to the concave undersurface of the corpus callosum is the thin vertical septum pellucidum anteriorly, and the fornix and its commissure posteriorly. Fiber tractsAlthough the corpus callosum can be seen as a single large fiber bundle connecting the two hemispheres, a number of individual fiber tracts can be identified. These include:
These connections can also be divided into:
The corpus callosum (CC) has a rich blood supply, relatively constant and is uncommonly involved by infarcts. The majority of the CC is supplied by the pericallosal arteries (the small branches and accompanying veins forming the pericallosal moustache) and the posterior pericallosal arteries, branches from the anterior and posterior cerebral respectively. In 80% of patients, additional supply comes from the anterior communicating artery, via either the subcallosal artery or median callosal artery.
Various small veins draining the central parts of the corpus callosum drain into the internal cerebral veins, in turn draining into the straight sinus. Tributaries of the internal cerebral veins draining the corpus callosum include 10:
In addition, pericallosal veins follow their arterial counterpart over the superficial surface of the corpus callosum:
The development of the corpus callosum occurs between the 12th and 16-20th weeks of gestation 6. Traditionally, it was believed that development begins in the genu and progresses posteriorly with the rostrum appearing last. More recent studies, including using MR tractography, cast some doubt on this assertion, instead suggesting that the anterior body develops first and then continues bidirectionally, with the anterior portions (genu) developing earlier/more prominently than the posterior portions (splenium) 7,8. This is not, however, universally accepted 11. Myelination of the corpus callosum occurs in the opposite direction, from the splenium forwards.
History and etymologyFrom the Latin, corpus meaning "body" and callosum, "hard" or "tough".
Related articles: Anatomy: BrainPromoted articles (advertising)Is the corpus callosum a commissure?The corpus callosum (Latin for "tough body"), also callosal commissure, is a wide, thick nerve tract, consisting of a flat bundle of commissural fibers, beneath the cerebral cortex in the brain. The corpus callosum is only found in placental mammals.
What is a commissure in the brain?Commissures are fiber tracts that are defined to connect corresponding cortical areas of both telencephalic hemispheres with each other. They comprise the anterior commissure, the hippocampal commissure, and the corpus callosum.
What is the large commissure that connects the right and left sides of the brain?The corpus callosum is the largest set of commissural fibers in the brain and is a pathway of crucial importance to speech-language functions (Fig. 2-10, B). The corpus callosum serves as the major connection between the hemispheres and conveys neural information from one hemisphere to the other.
What is the anterior and posterior commissure?The anterior commissure works with the posterior commissure to link the two cerebral hemispheres of the brain and also interconnects the amygdalae and temporal lobes, contributing to the role of memory, emotion, speech and hearing. It also is involved in olfaction, instinct, and sexual behavior.
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