VAN 121: Veterinary Gross Anatomy-II (2+2)

CEREBRAL CORTEX

• The cerebral cortex is made up of numerous convolutions or gyri and is separated by the sulci.
•  The great longitudinal fissure, which lodges the falx cerebri, divides the cerebrum into two equal halves completely.
• Centrally the fissure extends up to the corpus callosum. The corpus callosum is the connection between the two hemispheres at the median line. Beside the sulci, there are some longer depressions on the hemispheres. They are known as fissures. The fissures are as follows,
  • The coronal fissure is deep and is directed upward and medially over the frontal pole. It continues backward towards the medial border of the hemisphere where it ends.
  • The crucial fissure begins a little behind the middle of the great longitudinal fissure and passes across.
  • The rhinal fissure is a distinct furrow on the lower part of the lateral face of the hemisphere and it extends antero-posteriorly. This fissure separates the rhinencephalon below from the cerebral cortex or neopallium above.
  • The Sylvius fissure is on the lateral aspect, at the level of the fossa lateralis and lodges the middle cerebral artery. It passes vertically upwards for a short distance.
  • The callossal fissure is on the medial face and separates the corpus callosum from the gyrus fornicatus.
  • The calloso - marginal fissure is extensive and well defined and is on the medial face of the hemisphere. It lies parallel to the dorso-medial borders of the corpus callosum and curves like a “C” to the posterior part of the hemisphere. The posterior part of this fissure is the anterior calcarine fissure that shows a sulcus going upward and backward into the tentorial surface of the hemisphere and corresponds to the posterior calcarine fissure of man. (Click here to recollect the different Fissures in Dorsal view of brain)