layers of cerebral cortex
six anatomical divisions of the cerebral cortex (specifically, the isocortex), distinguished according to the types of cells and fibers they contain. Numbered from the surface inward, they are: I, molecular layer (lamina molecularis); II, external granular layer (lamina granularis externa); III, external pyramidal layer (lamina pyramidalis externa); IV, internal granular layer (lamina granularis interna); V, internal pyramidal layer (lamina pyramidalis interna); and VI, multiform layer (lamina multiformis). In official terminology, called strata isocorticis. See illustration.
Coronal section through the isocortex, showing the six layers.
Medical dictionary.
2011.