Corpus callosum

Most prominent and largest of the commissural fibres

Reciprocally interconnects broad regions of the opposite hemisphere

Forms the roof of the lateral ventricles

Lies below cingulate gyrus

Connected to fornix by septum pellucidum

Has the following parts:

a) Rostrum (1)
b) Genu (2)
c) Body (3)
d) Splenium (4)

Receives blood supply from pericallosal branches of anterior cerebral artery and the posterior cerebral artery.


It plays an important role in inter-hemispheric transfer of learned discriminations, sensory experience and memory.

Functional Localization in  the Corpus Callosum

  1. Anterior midbody transfers motor information

  2. Posterior midbody transfers somatosensory information
  3. Isthmus transfers auditory information and the splenium transfers visual information

 


Other Commissures

Anterior Commissure

Fornical commissure Habenular commissure Commissure of the colliculi Posterior commissure

Crosses the midline rostral to the columns of the fornix
It splits into:

  1. A  small anterior/ olfactory portion: Connect the olfactory bulbs

  2. A larger anterior portions: Connect the medial temporal gyri.

 

 

Connects the two crura of the fornix. Connects the habenular nuclei Connect the corresponding colliculi

Transition between brainstem and diencephalon

Has fibres from

a) Pretectal nuclei

b) Nuclei of posterior commissure

c) Interstitial nucleus

d) Nucleus of darkschwitch


Applied Anatomy

Split Brain Syndrome


Definition:

collection of signs and symptoms seen/observed in patients with partial or complete absence of corpus callosum. 

Causes:
1) Underdevelopment or agenesis in the corpus callosum
2) Surgical severance of corpus callosum
3) Callosal injuries

Affected Functions

  • Memory and cognition
  • Motor Control: