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External Granular Layer (cerebral Cortex)
The external granular layer of the cerebral cortex is commonly known as layer II. It is different from the internal granular layer of the cerebral cortex (commonly known as layer IV). Layer II is often grouped together with layer III and referred to as layer II/III. Layers I, II, and III are together referred to as the supragranular layers, because they are above layer IV. Brodmann has this to say about layer II: "The most inconstant or variable layers are Meynert's two so-called granular layers, layers II and IV of the basic pattern (the outer and inner granular layers). They alter their original cytoarchitectonic features so extensively during ontogeny that it is often only possible to correlate their mature structure with their primitive tectogenetic form by following the whole developmental sequence. Extreme variation, such as the disappearance or doubling of layers that we have already discussed, occur particularly in them, and their specific organisation also varies w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cerebral Cortex
The cerebral cortex, also known as the cerebral mantle, is the outer layer of neural tissue of the cerebrum of the brain in humans and other mammals. The cerebral cortex mostly consists of the six-layered neocortex, with just 10% consisting of allocortex. It is separated into two cortices, by the longitudinal fissure that divides the cerebrum into the left and right cerebral hemispheres. The two hemispheres are joined beneath the cortex by the corpus callosum. The cerebral cortex is the largest site of neural integration in the central nervous system. It plays a key role in attention, perception, awareness, thought, memory, language, and consciousness. The cerebral cortex is part of the brain responsible for cognition. In most mammals, apart from small mammals that have small brains, the cerebral cortex is folded, providing a greater surface area in the confined volume of the cranium. Apart from minimising brain and cranial volume, cortical folding is crucial for the brain ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Internal Granular Layer (cerebral Cortex)
The internal granular layer of the cortex, also commonly referred to as the granular layer of the cortex, is the layer IV in the subdivision of the mammalian cortex into 6 layers. The adjective internal is used in opposition to the external granular layer of the cortex, the term granular refers to the granule cells found here. This layer receives the afferent connections from the thalamus and from other cortical regions and sends connections to the other layers. The line of Gennari The line of Gennari (also called the "band" or "stria" of Gennari) is a band of myelinated axons that runs parallel to the surface of the cerebral cortex on the banks of the calcarine fissure in the occipital lobe. This formation is visible to the ... (occipital stripe) is also present in this layer. Cerebral cortex {{neuroanatomy-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
