Corpus callosum

The corpus callosum is a large C-shaped bundle of nerve fibers that connects the two cerebral hemispheres and carries information between them. (Neuroscience Online, Overview of the Nervous System)

Latin corpus callosum (Wikipedia, Corpus callosum, CC BY-SA 4.0) · FMA86464 · Nervous system

The brain model seen from the right with the cortex faded, showing the corpus callosum highlighted as an arch of white matter between the hemispheres. — The corpus callosum highlighted in the brain model, seen from the right through the faded cortex. Render: ScienceQuest, CC BY 4.0. Meshes: BodyParts3D, © The Database Center for Life Science, CC BY 4.0

The corpus callosum shown alone and seen from the right, a C-shaped band. — The corpus callosum on its own, seen from the right. Render: ScienceQuest, CC BY 4.0. Meshes: BodyParts3D, © The Database Center for Life Science, CC BY 4.0

Open it in the Brain Explorer See it alone in 3D

Where is the corpus callosum?

It is a band of white matter fibers that connects the left and right cerebral hemispheres. (OpenStax A&P 2e, 13.2; StatPearls, Corpus Callosum; Neuroscience Online, Overview of the Nervous System)

In a coronal section it forms a thick band of crossing fibers above the lateral ventricles. (Neuroscience Online, Overview of the Nervous System)

What are the parts of the corpus callosum?

It has a rostrum, a body and, at the back end, the splenium. The genu, or knee, joins the rostrum to the body. (Neuroscience Online, Overview of the Nervous System)

It holds about 200 million heavily myelinated fibers and is the brain’s main commissure, a tract that crosses the midline. (OpenStax Psychology 2e, 3.4; OpenStax Behavioral Neuroscience, 1.4; StatPearls, Corpus Callosum)

What does the corpus callosum do?

It carries information from one hemisphere to the other, so each side can use what the other has processed. (OpenStax Psychology 2e, 3.4; Neuroscience Online, Overview of the Nervous System)

Surgeons cut it in some people whose epilepsy drugs cannot control. Afterwards a patient may say they saw nothing when a picture flashes in the left visual field, which reaches only the right hemisphere, yet pick it out or draw it with the left hand. (OpenStax Psychology 2e, 3.4; de Haan et al. 2020, Neuropsychol Rev)

Even right-handed split-brain patients draw better with the left hand than the right, because the right hemisphere controls the left hand. (Neuroscience Online, Higher Cortical Functions: Association and Executive Processing)

What lies next to the corpus callosum?

The cingulate gyrus sits right above it. (OpenStax Behavioral Neuroscience, 1.4; Powell et al. 2018, Pract Neurol)

In a coronal section at the junction of the midbrain and diencephalon, it overlies the lateral ventricles, dorsomedial to the putamen and the insula. (Neuroscience Online, Overview of the Nervous System)

Touches in this model

Measured on the BodyParts3D meshes: surfaces within 2 mm of the corpus callosum, nearest first, 12 of 22.

Anterior commissure in contact
Hypothalamus in contact
Left caudate nucleus in contact
Left cingulate gyrus in contact
Left lateral ventricle in contact
Orbital gyri and straight gyri, both sides in contact
Right caudate nucleus in contact
Right cingulate gyrus in contact
Right lateral ventricle in contact
Septum pellucidum in contact
Third ventricle in contact
White matter structure of cerebral hemisphere in contact

Sources

Neuroscience Online, McGovern Medical School, Section 2, Chapter 1, Overview of the Nervous System. Nachum Dafny, Ph.D.. Last update Reviewed and revised 07 Oct 2020. Open access; no reuse licence stated. Read 2026-10-25.
OpenStax Anatomy and Physiology 2e, section 13.2, The Central Nervous System. CC BY-NC-SA 4.0. Read 2026-10-25.
StatPearls, Neuroanatomy, Corpus Callosum (introduction, read as the abstract on Europe PMC, PMID 28846239). Goldstein A, Covington BP, Mahabadi N, Mesfin FB. Abstract read on Europe PMC; no reuse licence stated. Read 2026-10-25.
OpenStax Psychology 2e, section 3.4, The Brain and Spinal Cord. CC BY-NC-SA 4.0. Read 2026-10-25.
OpenStax Introduction to Behavioral Neuroscience, section 1.4, The Brain: Structure and Function. CC BY-NC-SA 4.0. Read 2026-10-25.
Neuropsychology Review, Split-Brain: What We Know Now and Why This is Important for Understanding Consciousness, Neuropsychol Rev 30, pages 224 to 233 (full text, PMC7305066). de Haan EHF, Corballis PM, Hillyard SA, Marzi CA, Seth A, Lamme VAF, Volz L, Fabri M, Schechter E, Bayne T, Corballis M, Pinto Y. CC BY. Read 2026-10-25.
Neuroscience Online, McGovern Medical School, Section 4, Chapter 9, Higher Cortical Functions: Association and Executive Processing. Anthony Wright, Ph.D.. Last update Last Review 07 July 2026. Open access; no reuse licence stated. Read 2026-10-25.
Practical Neurology, Cingulate gyrus epilepsy, Pract Neurol 18, pages 447 to 454 (abstract, PMID 30100562). Powell R, Elwes R, Hamandi K, Mullatti N. Abstract read on Europe PMC; no reuse licence stated. Read 2026-10-25.