What are the shells of the brain

The human brain is the organ of the central nervous system, which consists of a huge number of related processes of nerve cells and is responsible for all the functions of the body. The cavity of the cranial region, in which the brain substance is contained, protects bones from external mechanical influences. The brain, as well as the dorsal one, is covered with three shells: hard, soft and spiny, each of which performs its functions.

The structure of the solid membrane of the brain

A solid hard shell of the brain is a dense periosteum of the skull, with which it has a strong connection. The inner surface of the shell has several processes that penetrate into deep cerebral fissures in order to separate the divisions. The largest such process is located between the two hemispheres, being a kind of sickle, the posterior part of which fuses with the hint of the cerebellum and limits it from the occipital lobes. On the surface of the dense shell of the brain there is another process that is located around the Turkish saddle, forming a kind of diaphragm and providing protection of the pituitary gland from excessive pressure of the brain mass. In the corresponding areas there are special sinuses, called sinuses, through which the venous blood flows.

The structure of the spider web of the brain of the head

The spiderweb of the brain is located on the inside of the hard shell. Although it is very thin and transparent, it does not penetrate the cracks and furrows of the hemispheres, covering the entire surface of the brain substance and passing from one part to another. From the cerebral vasculature of the brain spider web separates the subarachnoid space, which is filled with cerebrospinal fluid. Where the shell is located above the deep and wide furrows, the subarachnoid space becomes wider, forming various sizes of the cistern. Above the convex parts, especially above the convolutions, the soft and arachnoid shells of the brain are closely pressed against each other, therefore the subarachnoid space in these regions substantially narrows and represents a capillary gap.

The names of large sub-paternal tanks :

• The cerebellum-medulla is located in a depression between the cerebellum and the place where the medulla oblongata is located;
• The sinus of the lateral fossa is located on the lower lateral side of the cerebral hemisphere;
• The cross-over tank functions at the base of the brain of the head, from the front part of the visual crossover;
• Localization mezhozhkovoy cistern - between the legs of the brain in the intercostal fossa.

The shells of the brain are connective tissue structures that also cover the spinal cord. They perform the function of protection, creating a histohematological, liquor-tissue and liquor-hematopic barriers, which are related to metabolic processes and the outflow of cerebrospinal matter. Without these structures, normal functioning of the brain and sufficient supply of all vital substances to it are impossible.