Lateral ventricle: anatomy, function

The lateral ventricle, together with the remaining cavities in the brain, is part of the general system in which the cerebrospinal fluid circulates. They communicate with the subarachnoid space of the spinal cord. The inner surface of these cavities is lined with ependyma. Their function is to maintain an optimal range of pressure inside and outside the brain and spinal cord.

Types of the ventricles of the brain

The lateral ventricle (s) are small cavities in the large brain that produce a specific cerebrospinal fluid. They are considered to be the largest of the ventricular system. This is a pair formation, and for it there is a specific topography.

The left lateral ventricle, by tradition, is called the first. And the right one is second. They are symmetrical between themselves and the neighboring anatomical formations, and are located below the epiphysis on either side of the median line. In each ventricle, the body and horns are distinguished: anterior, posterior and inferior. Lateral ventricles through the holes of the Monroe are connected to the third ventricle.

The third ventricle is located between the areas responsible for vision. It has the form of a ring and in its wall there is a gray matter of the brain containing vegetative ganglia. In addition to the lateral ventricles, this cavity is connected to the water supply of the brain.

The fourth ventricle is located between the lower cerebellum. In form it resembles a pyramid and it is more correctly called a diamond-shaped fossa. In addition to cerebrospinal fluid, most of the nuclei of the spinal nerves are located at the bottom of this fossa.

Vascular plexus

The lateral ventricle (s) are only partially implicated in such a concept as the vascular plexus. The bulk of these structures is located in the roofs of the third and fourth ventricles. They are responsible for most of the production of cerebrospinal fluid. In addition to them, this function is performed directly by the nervous tissue, as well as ependyma, which covers the inside of the ventricles of the brain.

Morphologically, the vascular plexuses are the outgrowths of the pia mater, immersed in the ventricles. Outwardly these protrusions are covered with a cubic specific chrooid epithelium.

Ependymocytes

The lateral ventricles of the brain are lined from the inside with a special tissue, which can, how to produce the cerebrospinal fluid, and absorb it. This helps to maintain the optimal amount of fluid in the cavity and prevent increased intracranial pressure.

The cells of this epithelium have many organelles and a large nucleus. Their outer surface is covered with a large number of microvilli, they help advance the cerebrospinal fluid, as well as its absorption. Outside the ependyma, Colmer cells are located, which are considered to be a special kind of macrophages that can move around the body.

Through multiple small lumens in the basal membrane of epydemocytes, blood plasma swims into the cavity of the ventricles. To it proteins are added, produced directly by the cells of the inner epithelium of the brain cavities, and so the liquor is obtained.

Blood-brain barrier

The body and horns of the lateral ventricles with their internal lining form a blood-brain or hematolymph barrier. It is a collection of tissues arranged in a certain order:

- Cytoplasm of endothelium of capillaries;

- connective tissue containing macrophages;

- basal membrane of the endothelium;

Ependyma cells;

- basal membrane of ependyma.

Such a complex construction is necessary in order to prevent the ingestion of metabolic products, drugs and other toxic substances into the cerebrospinal fluid.

Cerebrospinal fluid

The norm of the lateral ventricles is the production of half a liter of liquor per day, but only one hundred and forty milliliters of this quantity is constantly circulating in the subarachnoid space. Despite the fact that the basis for cerebrospinal fluid is blood plasma, they have significant differences in the number of electrolytes and protein. The first is much higher, and the second is lower. In addition, there is a small amount of lymphocytes in the CSF. The reverse absorption of cerebrospinal fluid occurs at the sites of vascular plexus insertion.

The following liquor functions are distinguished:

- detoxification (transportation of metabolic products);

- depreciation (for walking, falling, sharp bends);

- the formation of a hydrostatic shell around the elements of the nervous system;

- maintaining the constancy of the composition of liquids in the central nervous system;

- transport (transfer of hormones and some drugs).

Diseases of the ventricles

When one lateral ventricle (or both) produces more fluid than is capable of absorbing, a pathological condition develops, such as hydrocephalus. The internal volume of the ventricles of the brain gradually increases, squeezing the brain tissue. Sometimes this leads to irreversible ischemia and necrosis.

In newborns and small children, the symptoms of this disease are the disproportionate size of the cerebral cranium as compared to the facial, the bulging of the fontanelles, the child's unreasonable anxiety, turning into apathy. In adults, there are complaints of headache, pain in the eye, nausea and vomiting.

For diagnosis, methods of neuroimaging are used: magnetic resonance therapy or computed tomography. Timely detection and treatment of this disease can avoid a significant number of complications and preserve the possibility of normal life.