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Grey matter in the spinal cord is known as the grey column which travels down the spinal cord distributed in three grey columns that are presented in an "H" shape. The forward-facing column is the anterior grey column , the rear-facing one is the posterior grey column and the interlinking one is the lateral grey column .
There are many small variations in the secondary and tertiary folds. [20] The outer part of the cerebrum is the cerebral cortex, made up of grey matter arranged in layers. It is 2 to 4 millimetres (0.079 to 0.157 in) thick, and deeply folded to give a convoluted appearance. [21] Beneath the cortex is the cerebral white matter.
The neocortex is the most developed in its organisation and number of layers, of the cerebral tissues. [5] The neocortex consists of the grey matter, or neuronal cell bodies and unmyelinated fibers, surrounding the deeper white matter (myelinated axons) in the cerebrum. This is a very thin layer though, about 2–4 mm thick. [6]
Visually, the interior of the brain consists of areas of so-called grey matter, with a dark color, separated by areas of white matter, with a lighter color. Further information can be gained by staining slices of brain tissue with a variety of chemicals that bring out areas where specific types of molecules are present in high concentrations.
The grey columns, (three regions of grey matter) in the center of the cord, is shaped like a butterfly and consists of cell bodies of interneurons, motor neurons, neuroglia cells and unmyelinated axons. The anterior and posterior grey columns present as projections of grey matter and are also known as the horns of the spinal cord.
White matter is composed of bundles, which connect various grey matter areas (the locations of nerve cell bodies) of the brain to each other, and carry nerve impulses between neurons. Myelin acts as an insulator, which allows electrical signals to jump , rather than coursing through the axon, increasing the speed of transmission of all nerve ...
Because of its large number of tiny granule cells, the cerebellum contains more neurons than the total from the rest of the brain, but takes up only 10% of the total brain volume. [11] The number of neurons in the cerebellum is related to the number of neurons in the neocortex. There are about 3.6 times as many neurons in the cerebellum as in ...
Tangential growth suggests that the grey matter grows at a faster rate than the inner white matter and that the growth rate of the grey matter determines the growth rate of the white matter. Though both methods are differential, with the cortex growing more rapidly than the subcortex, tangential growth has been suggested as a more plausible model.