The central nervous system makes up the dorsal andbrain. The substance of the brain in its composition is heterogeneous, it is formed by white and gray matter. White is composed of nerve fibers, their outgrowths having, respectively, a white color. Gray is the accumulation of nerve cells and outgrowths of these cells.
Gray matter of the spinal cord
It is formed by a very large number of neurons of threetypes, which are grouped into nuclei: radicular cells, bundle neurons, internal cells. Located inside, and surrounded by white matter. It is more developed in the cervical and lumbar parts, which is associated with an increase in motor neurons.
In the center there is a central channel, whichpasses through the entire length of the spinal cord, for that it is central. Contained in the canal of cerebrospinal fluid. It is surrounded by a gray substance, which is called an intermediate substance. Here, the gray matter can be divided into paired front, twin rear and side columns. Accordingly, on the transverse section distinguish three horns: front, side and rear.
Gray matter of the brain
The brain of the dorsal passes, without any changes,in the brain oblong. The boundary that forms between the oblong and dorsal is the place where the roots of the first pair of nerves of the spinal cord come out. The departments of the upper part are thicker than the lower ones. In the brain oblong are the nuclei responsible for the balance, coordination, metabolism, circulation and respiration. The hindbrain consists of two parts: a bridge and a cerebellum.
The bridge is a white roller located on the sidebases of the brain. In front you can see the border with the legs of the brain, and behind - with an oblong brain. The cross-section shows the substance white, and also, the core of gray. The continuation of the medulla oblongata is the dorsal part of the bridge, in which the nuclei of sensory systems and cranial nerves are located. Here the gray matter of the brain predominates. The cerebellum is located under the occipital part of the brain. It consists of the hemispheres and the middle part - the worm. The worm connects the two hemispheres. The cerebellum covers a layer of gray matter that makes up the cerebellar cortex, forming convolutions. A white substance penetrates into the gyrus. Above them covers the gray matter of the brain. The picture in the cut is very similar to a tree.
Among the nuclei of gray matter, the most important and most importantmeaningful is the red core, which serves as the focal point. The mid-brain duct is a narrow canal, the length of which is two centimeters. He connects the ventricles, the third and fourth. This channel frames the gray matter of the brain, which is central and consists of small cells. In the intermediate brain the substance consists of nuclei belonging to the centers located under the cortex and responsible for all kinds of sensitivity. The final brain, consists of two parts, two hemispheres. The cerebral cortex is the gray matter of the brain in the form of a thin plate. It is formed by nerve cells in huge numbers. These cells can be divided into layers. Each layer, in turn, has its own specific features.
So, the gray matter is a collection of neurons anddendrites. Cluster occurs in the central nervous system, which is formed by the spinal cord and the brain. This substance forms the cortex of the brain, as well as the subcortical nuclei. The substance in the spinal cord is formed by nerve cells, of which there are about thirteen million. The amount of gray matter contained in the brain is able to influence the level of development of the intellect. It is assumed that the additional volume of gray matter allows for much faster processing of information.</ p>>