Functions of the soft membrane of the spinal cord. Arachnoid. Connection between shells

The spinal cord is covered on the outside with membranes that are a continuation of the membranes of the brain. They perform the functions of protection against mechanical damage, provide nutrition to neurons, control water metabolism and metabolism of nervous tissue. Cerebrospinal fluid, which is responsible for metabolism, circulates between the membranes.

The spinal cord and brain are parts of the central nervous system, which responds to and controls all processes occurring in the body - from mental to physiological. The functions of the brain are more extensive. The spinal cord is responsible for motor activity, touch, and sensation in the arms and legs. The membranes of the spinal cord perform specific tasks and ensure coordinated work to provide nutrition and remove metabolic products from brain tissue.

The structure of the spinal cord and surrounding tissues

If you carefully study the structure of the spine, it will become clear that the gray matter is securely hidden, first behind the movable vertebrae, then behind the membranes, of which there are three, followed by the white matter of the spinal cord, which ensures the conduction of ascending and descending impulses. As you go up the spinal column, the amount of white matter increases, as more controlled areas appear - arms, neck.

White matter is axons (nerve cells) covered with a myelin sheath.

Gray matter provides communication between internal organs and the brain using white matter. Responsible for memory processes, vision, emotional status. Gray matter neurons are not protected by the myelin sheath and are very vulnerable.

To simultaneously provide nutrition to the neurons of the gray matter and protect it from damage and infection, nature has created several obstacles in the form of the spinal membranes. The brain and spinal cord have identical protection: the membranes of the spinal cord are a continuation of the membranes of the brain. To understand how the spinal canal works, it is necessary to carry out a morphofunctional characterization of each individual part of it.

Functions of the hard shell

The dura mater is located just behind the walls of the spinal canal. It is the densest and consists of connective tissue. It has a rough structure on the outside, and the smooth side faces inward. The rough layer provides a tight seal with the vertebral bones and holds soft tissue in the spinal column. The smooth endothelium layer of the spinal cord dura is the most important component. Its functions include:

production of hormones - thrombin and fibrin;
exchange of tissue and lymphatic fluid;
blood pressure control;
anti-inflammatory and immunomodulatory.

During the development of the embryo, connective tissue comes from mesenchyme - cells from which blood vessels, muscles, and skin subsequently develop.

The structure of the outer shell of the spinal cord is determined by the necessary degree of protection of the gray and white matter: the higher, the thicker and denser it is. At the top it fuses with the occipital bone, and in the area of the coccyx it thins out to several layers of cells and looks like a thread.

The same type of connective tissue forms a protection for the spinal nerves, which is attached to the bones and reliably fixes the central canal. There are several types of ligaments with which the external connective tissue is attached to the periosteum: these are lateral, anterior, and dorsal connecting elements. If it is necessary to remove the hard shell from the bones of the spine - a surgical operation - these ligaments (or cords) pose a problem for the surgeon due to their structure.

Arachnoid

The layout of the shells is described from external to internal. The arachnoid membrane of the spinal cord is located behind the dura mater. Through a small space it adjoins the endothelium from the inside and is also covered with endothelial cells. It looks translucent. The arachnoid membrane contains a huge number of glial cells that help generate nerve impulses, participate in the metabolic processes of neurons, secrete biologically active substances, and perform a support function.

The question of the innervation of the arachnoid film is controversial for physicians. It has no blood vessels. Also, some scientists consider the film as part of the soft shell, since at the level of the 11th vertebra they merge into one.

The median membrane of the spinal cord is called the arachnoid, as it has a very thin structure in the form of a web. Contains fibroblasts - cells that produce extracellular matrix. In turn, it ensures the transport of nutrients and chemicals. With the help of the arachnoid membrane, the cerebrospinal fluid moves into the venous blood.

The granulations of the medial shell of the spinal cord are villi, which penetrate the outer hard shell and exchange liquor fluid through the venous sinuses.

Inner shell

The soft shell of the spinal cord is connected to the hard shell with the help of ligaments. The wider area of the ligament is adjacent to the soft shell, and the narrower area is adjacent to the outer shell. In this way, the three membranes of the spinal cord are fastened and fixed.

The anatomy of the soft layer is more complex. This is loose tissue containing blood vessels that deliver nutrition to neurons. Due to the large number of capillaries, the color of the fabric is pink. The soft membrane completely surrounds the spinal cord, its structure is denser than similar brain tissue. The membrane adheres so tightly to the white matter that with the slightest dissection it appears from the cut.

It is noteworthy that such a structure is found only in humans and other mammals.

This layer is well washed by blood and therefore performs a protective function, since the blood contains a large number of leukocytes and other cells responsible for human immunity. This is extremely important, since the entry of microbes or bacteria into the spinal cord can cause intoxication, poisoning and death of neurons. In such a situation, you can lose the sensitivity of certain areas of the body for which the dead nerve cells were responsible.

The soft shell has a two-layer structure. The inner layer is the same glial cells that are in direct contact with the spinal cord and provide its nutrition and removal of waste products, and also participate in the transmission of nerve impulses.

Spaces between the membranes of the spinal cord

The 3 shells do not touch each other tightly. Between them there are spaces that have their own functions and names.

Epidural the space is between the bones of the spine and the hard shell. Filled with adipose tissue. This is a kind of protection against lack of nutrition. In emergency situations, fat can become a source of nutrition for neurons, which will allow the nervous system to function and control processes in the body.

The looseness of adipose tissue is a shock absorber, which, under mechanical action, reduces the load on the deep layers of the spinal cord - the white and gray matter, preventing their deformation. The membranes of the spinal cord and the spaces between them represent a buffer through which the upper and deep layers of tissue communicate.

Subdural the space is between the dura mater and the arachnoid (arachnoid) membrane. It is filled with cerebrospinal fluid. This is the most frequently changing medium, the volume of which is approximately 150 - 250 ml in an adult. The fluid is produced by the body and is renewed 4 times a day. In just one day, the brain produces up to 700 ml of cerebrospinal fluid (CSF).

Liquor performs protective and trophic functions.

In case of mechanical impact - impact, fall, it maintains pressure and prevents deformation of soft tissues, even with breaks and cracks in the bones of the spine.
The liquor contains nutrients - proteins, minerals.
White blood cells and lymphocytes in the cerebrospinal fluid suppress the development of infection near the central nervous system by absorbing bacteria and microorganisms.

CSF is an important fluid that doctors use to determine if a person has had a stroke or brain injury that compromises the blood-brain barrier. In this case, red blood cells appear in the liquid, which should not normally be the case.

The composition of the cerebrospinal fluid changes depending on the work of other human organs and systems. For example, if there are disturbances in the digestive system, the liquid becomes more viscous, as a result of which the flow becomes more difficult and painful sensations appear, mainly headaches.

Decreased oxygen levels also disrupt the functioning of the nervous system. First, the composition of the blood and intercellular fluid changes, then the process is transferred to the cerebrospinal fluid.

A big problem for the body is dehydration. First of all, the central nervous system suffers, which, in difficult conditions of the internal environment, is not able to control the functioning of other organs.

The subarachnoid space of the spinal cord (in other words, subarachnoid) is located between the pia mater and the arachnoid. This is where the largest amount of liquor is located. This is due to the need to ensure the greatest safety of certain parts of the central nervous system. For example, the brainstem, cerebellum or medulla oblongata. There is especially a lot of cerebrospinal fluid in the area of the trunk, since all the vital sections that are responsible for reflexes and breathing are located there.

If there is a sufficient amount of fluid, mechanical external influences on the area of the brain or spine reach them to a much lesser extent, since the fluid compensates and reduces the impact from the outside.

In the arachnoid space, fluid circulates in various directions. The speed depends on the frequency of movements and breathing, that is, it is directly related to the work of the cardiovascular system. Therefore, it is important to maintain a regimen of physical activity, walking, proper nutrition and drinking water.

Cerebrospinal fluid exchange

Liquor enters the circulatory system through the venous sinuses and is then sent for purification. The system that produces the fluid protects it from the possible entry of toxic substances from the blood, and therefore selectively passes elements from the blood into the cerebrospinal fluid.

The membranes and intershell spaces of the spinal cord are washed by a closed system of cerebrospinal fluid, therefore, under normal conditions, they ensure stable functioning of the central nervous system.

Various pathological processes that begin in any part of the central nervous system can spread to neighboring ones. The reason for this is the continuous circulation of cerebrospinal fluid and the transfer of infection to all parts of the brain and spinal cord. Not only infectious, but also degenerative and metabolic disorders affect the entire central nervous system.

Cerebrospinal fluid analysis is key in determining the extent of tissue damage. The state of the cerebrospinal fluid allows one to predict the course of diseases and monitor the effectiveness of treatment.

Excess CO2, nitric and lactic acids are removed into the bloodstream so as not to create a toxic effect on nerve cells. We can say that the cerebrospinal fluid has a strictly constant composition and maintains this constancy with the help of the body’s reactions to the appearance of an irritant. A vicious circle occurs: the body tries to please the nervous system, maintaining balance, and the nervous system, with the help of streamlined reactions, helps the body maintain this balance. This process is called homeostasis. It is one of the conditions for human survival in the external environment.

Connection between shells

The connection between the membranes of the spinal cord can be traced from the earliest moment of formation - at the stage of embryonic development. At the age of 4 weeks, the embryo already has the rudiments of the central nervous system, in which various tissues of the body are formed from just a few types of cells. In the case of the nervous system, this is the mesenchyme, which gives rise to the connective tissue that makes up the membranes of the spinal cord.

In the formed body, some membranes penetrate one another, which ensures metabolism and the performance of general functions to protect the spinal cord from external influences.

The spinal cord (medulla spinalis) is a section of the human central nervous system located in the spinal canal. The spinal canal is formed by a collection of vertebral foramina in the vertebrae. The spinal cord has the shape of a cylindrical cord with an internal cavity (spinal canal), and is held in a constant position by ligaments. The anterior (upper) end of the spinal cord passes into the medulla oblongata, and the posterior (lower) end into the so-called filum terminale.

Spinal nerves are nerves that run from the spinal cord to almost every area of the body, from the back of the head to the lower extremities. The spinal nerves start from the junction of the anterior (motor) and posterior (sensitive) roots and represent a trunk (up to 1 cm in diameter) going to the periphery.

Thus, changes in the spine leading to pinching of the nerve spine, root, damage to blood vessels, etc., lead to a disruption in the functioning of the organ for which the damaged nerve spine is responsible.

Sheaths of the spinal cord.

There are three membranes of the spinal cord: hard, arachnoid and soft.

The hard shell is a cylindrical sac closed at the bottom, repeating the shape of the spinal canal.

This sac starts from the edge of the foramen magnum and continues to the level of the II-III sacral vertebra. It contains not only the spinal cord, but also the cauda equina. Below the II-III sacral vertebra, the hard shell continues for about 8 cm in the form of the so-called external filum terminale. It stretches to the second coccygeal vertebra, where it fuses with its periosteum. Between the periosteum of the spinal column and the hard shell is the epidural space, which is filled with a mass of loose fibrous connective tissue containing adipose tissue. The internal vertebral venous plexus is well developed in this space. The dura mater of the brain is built from dense fibrous connective tissue, is abundantly supplied with blood, and is well innervated by sensory branches from the spinal nerves.

The dura mater sac is strengthened in the spinal canal so that the dura mater extends onto the roots of the spinal nerves and the nerves themselves. The continuation of the hard shell grows to the edges of the intervertebral foramina. In addition, there are strands of connective tissue that attach the periosteum of the spinal canal and the dura mater to each other. These are the so-called anterior, dorsal and lateral ligaments of the dura mater.

The hard shell of the spinal cord is covered on the inside with a layer of flat connective tissue cells that resemble the mesothelium of the serous cavities, but do not correspond to it. Beneath the dura mater is the subdural space.

The arachnoid membrane is located inside the dura mater and forms a sac containing the spinal cord, the roots of the spinal nerves, including the roots of the cauda equina, and cerebrospinal fluid. The arachnoid membrane is separated from the spinal cord by the wide subarachnoid space, and from the dura mater by the subdural space. The arachnoid membrane is thin, translucent, but quite dense. It is based on reticular connective tissue with cells of various shapes. The arachnoid membrane is covered on the outer and inner sides with flat cells resembling mesothelium or endothelium. The existence of nerves in the arachnoid membrane is controversial.

Under the arachnoid membrane is the spinal cord, covered with a soft, or vascular, membrane fused to its surface. This connective tissue membrane consists of an outer longitudinal and inner circular layer of bundles of connective tissue collagen fibers; they are fused with each other and with the brain tissue. In the thickness of the soft shell there is a network of blood vessels intertwining the brain.

Their branches penetrate into the thickness of the brain, carrying with them the connective tissue of the soft shell.

Between the arachnoid and soft membranes there is a subarachnoid space. Cerebrospinal fluid fills beneath the arachnoid spaces of the spinal cord and brain, which communicate with each other through the foramen magnum.

Enters the central nervous system. In the human body, it is responsible for motor reflexes and the transmission of nerve impulses between organs and the brain. The membranes covering the spinal cord provide protection. What features and differences do they have?

Structure

The vertebral arches form a cavity called the spinal canal, in which the spinal cord is located along with blood vessels and nerve roots. Its upper part connects to the medulla oblongata (head section), and the lower part connects to the periosteum of the second coccygeal vertebra.

The spinal cord looks like a thin white cord, the length of which in humans reaches 40-45 centimeters, and the thickness increases from bottom to top. Its surface is slightly concave. It consists of thirty-one segments, from which pairs of nerve roots emerge.

The spinal cord is covered with membranes on the outside. It contains gray inside and their ratio varies in different parts. The gray matter has the shape of a butterfly, it contains the bodies of nerve cells, their processes contain white matter, which is located at the edges.

In the center of the gray matter is a canal. It is filled with cerebrospinal fluid (CSF), which constantly circulates in the brain and spinal cord. In an adult, its volume is up to 270 milliliters. Liquor is produced in the ventricles of the brain and is renewed 4 times a day.

Spinal cord membranes

Three membranes: hard, arachnoid and soft - cover both the brain and the spinal cord. They perform two main functions. Protective prevents the negative effects of mechanical impact on the brain. associated with the regulation of cerebral blood flow, due to which metabolism occurs in tissues.

The membranes of the spinal cord are made up of connective tissue cells. On the outside there is a hard shell, underneath it is arachnoid and soft. They do not fit tightly together. Between them there is a subdural and subarachnoid space. They are attached to the spine by plates and ligaments that prevent the brain from being pulled out.

The membranes are formed at the beginning of the second month of embryonic development. Connective tissue forms on the neural tube and spreads along it. Later, the tissue cells separate to form the outer and inner membranes. After some time, the inner shell is divided into soft and arachnoid.

Dura shell

The outer hard shell consists of an upper and lower layer. It has a rough surface on which many vessels are located. Unlike a similar membrane in the brain, it does not fit tightly to the walls of the spinal canal and is separated from them by the venous plexus and fatty tissue.

The dura mater of the spinal cord is a dense, shiny fibrous tissue. It envelops the brain in the form of an elongated cylindrical sac. The coverings make up the bottom layer of the shell.

It envelops the nodes and nerves, forming cavities that expand as they approach the intervertebral foramina. Near the head, the shell connects to the occipital bone. It narrows downward and is a thin thread that attaches to the coccyx.

Blood passes to the membrane through arteries connected to the abdominal and thoracic aorta. Venous blood enters the venous plexus. The membrane is fixed in the spinal canal with the help of processes and fibrous bundles.

Arachnoid

A slit-like space with a large number of connecting bundles separates the dura mater and the arachnoid membrane of the spinal cord. The latter has the appearance of a thin sheet, it is transparent and contains fibroblasts (connective tissue fibers that synthesize the extracellular matrix).

The arachnoid membrane of the spinal cord is enveloped in neuroglia - cells that ensure the transmission of nerve impulses. It does not contain blood vessels. Processes, thread-like trabeculae, extend from the arachnoid membrane, intertwining into the next soft shell.

Below the membrane is the subarachnoid space. It contains liquor inside. It is expanded in the lower part of the spinal cord, in the area of the sacrum and coccyx. In the neck area there is a partition between the soft and arachnoid membranes. The septum and dentate ligaments between the nerve roots secure the brain in one position, preventing it from moving.

Soft shell

The inner shell is soft. It envelops the spinal cord. Compared to a similar structure in the brain, it is considered stronger and thicker. The pia mater of the spinal cord consists of loose tissue covered by endothelial cells.

It has two thin layers, between which there are numerous blood vessels. On the top layer, represented by a thin plate or leaf, there are jagged ligaments that secure the shell. Adjacent to the inner part is a membrane that connects directly to the spinal cord. The membrane forms a sheath for the artery and, together with it, penetrates the brain and its gray matter.

The soft shell is present only in mammals. Other terrestrial vertebrates (tetrapods) have only two - hard and internal. During evolutionary development, the internal membrane in mammals was divided into arachnoid and soft.

Conclusion

The spinal cord belongs to the central nervous system of all vertebrates, including humans. It performs reflex and conductive functions. The first is responsible for the reflexes of the limbs - their flexion and extension, jerking, etc. The second function is the conduction of nerve impulses between the organs and the brain.

The hard, arachnoid and soft membranes envelop the spinal cord from the outside. They perform protective and trophic (nutritional) functions. The membranes are formed by connective tissue cells. They are separated from each other by spaces that are filled with cerebrospinal fluid - a fluid circulating in the spinal cord and brain. The shells are connected to each other by thin fibers and processes.

The membranes of the brain and spinal cord come in only a few types. Modern medicine distinguishes hard, arachnoid and soft structures. Their main task is to protect the brain from stress, concussions, injuries, microtraumas and other factors that can negatively affect the functioning of the nervous system, and to nourish the brain with useful elements. Without them, the cerebrospinal fluid alone would not be able to fully cope with the shock-absorbing function.

Structural features

The spinal cord and brain are a single whole, an integral part of the nervous system. All mental functions, control of vital processes (activity, touch, sensitivity of the limbs) are carried out with their help. They are covered with protective structures that work harmoniously to provide nutrition and remove metabolic products.

The membranes of the spinal cord and brain are largely similar in structure. They continue the spine and envelop the spinal cord, preventing damage to it. This is a kind of “clothing” of the most important human organ, characterized by increased sensitivity. All layers are interconnected and they function as one, although their tasks are slightly different. There are three shells in total, and each has its own characteristics.

Dura shell

It is a fibrous formation with increased density, consisting of connective tissue. In the spine, it envelops the brain along with nerves and roots, spinal ganglia, as well as other membranes and fluid. The outer part is separated from the bone tissue by the epidural space, which consists of venous bundles and a fatty layer.

The hard shell of the spinal cord is inextricably linked with the same structure of the brain. In the head, the latter is fused with the periosteum, therefore it fits tightly to the inner surface of the skull, without forming an epidural space, which is its characteristic feature. The space between the dura mater and the arachnoid membrane is called the subdural; it is very narrow and filled with fluid similar to tissue.

The main functions of the hard shell are to create natural shock absorption, which reduces pressure and eliminates mechanical impact on the brain structure during movement or injury. In addition, there are a number of other tasks:

synthesis of thrombin and fibrin - important hormones in the body;
ensuring normal metabolic processes in tissues and lymph movement;
normalization of blood pressure in the body;
suppression of inflammatory processes;
immunomodulation.

In addition, the shell has such an anatomy that it takes part in the blood supply. Tight closure with the vertebral bones allows it to reliably fix soft tissues in the ridge. This is important to ensure their safety during movement, physical exercise, falling, or injury.

Important! Connective tissue is attached to the periosteum by several types of ligaments: anterior, lateral, dorsal. If it is necessary to remove the dura mater, they present a serious obstacle for the surgeon due to the peculiarities of their structure.

Arachnoid

The arachnoid membrane of the human spinal cord is located on the outer part of the soft tissue, but deeper than the hard tissue. It covers the structure of the central nervous system and is devoid of color and blood vessels. In general, it is a connective tissue covered by endothelial cells. Connecting with the hard shell, it forms a space where the cerebrospinal fluid functions, but does not enter the grooves or depressions, passes by them, forming something like bridges. It is this cerebrospinal fluid that protects the nerve structures from various adverse effects and maintains water balance in the system.

Its main functions are:

formation of hormones in the body;
maintaining natural metabolic processes;
transportation of cerebrospinal fluid into the venous blood;
mechanical protection of the brain;
formation of nervous tissue (in particular, cerebrospinal fluid);
generation of nerve impulses;
participation in metabolic processes in neurons.

The middle shell has a complex structure and looks like a mesh fabric, with a small thickness but high strength. It was its resemblance to a spider's web that gave it its name. Some experts believe that it is devoid of nerve endings, but this is only a theory that has not been proven to date.

Visual structure and location of the spinal cord membranes

Soft shell

Closest to the brain is the soft shell, which has a loose structure and consists of connective tissue. It contains blood vessels and plexuses, nerve endings and small arteries, all of which are responsible for providing the brain with enough blood for normal functioning. Unlike the arachnoid, it goes into all the cracks and grooves.

But, despite their close location, the brain is not covered by it, since between them there is a small space called subpial. It is separated from the subarachnoid space by many blood vessels. Its main functions include supplying the brain with blood and nutrients, normalizing metabolism and metabolism, as well as maintaining the natural performance of the body.

The functioning of all membranes is interconnected and the structure of the spine as a whole. Various malfunctions, changes in the amount of cerebrospinal fluid or inflammatory processes at any level lead to serious consequences and disorders and diseases of internal organs.

Spaces between shells

All the membranes of the spinal cord and brain, although they are close to each other, do not touch tightly. Spaces are formed between them, which have their own characteristics and functions.

Epidural. It is located between the hard shell and the bone tissue of the spinal column. It is filled predominantly with fat cells to eliminate nutritional deficiencies. Cells become a strategic reserve for neurons in extreme situations, which ensures the control and functioning of processes in the body. This space reduces the load on the deep layers of the spinal cord, eliminating their deformation, due to its loose structure.
Subdural. Located between the dura mater and the arachnoid membrane. It contains liquor, the amount of which always changes. On average, an adult has 150–250 ml. Cerebrospinal fluid provides the brain with nutrients (minerals, proteins), protects it from falls or impacts, maintaining pressure. Thanks to the movement of cerebrospinal fluid and its constituent lymphocytes and leukocytes, infectious processes are suppressed in the central nervous system and bacteria and microorganisms are absorbed.
Subarachnoid. Located between the arachnoid and soft membrane. It constantly contains most of the cerebrospinal fluid. This allows you to most effectively protect the central nervous system, brainstem, cerebellum and medulla oblongata.

In case of tissue damage, the first step is to analyze the cerebrospinal fluid, as it allows you to determine the extent of the pathological process, predict the course, and choose effective control tactics. An infection or inflammation that appears in one area quickly spreads to neighboring ones. This is due to the constant movement of cerebrospinal fluid.

Diseases

The meninges can be injured or suffer from damage of an infectious nature. Increasingly, problems are associated with the development of oncology. They are recorded in patients of different ages and health conditions. In addition to infectious processes, there are other malfunctions:

Fibrosis. It represents a negative consequence of the surgical intervention. It leads to an increase in the volume of the membrane, characteristic tissue scarring, and an inflammatory process that occurs immediately in all intershell spaces. The disease is also often provoked by cancer or spinal injuries.
Meningitis. Severe pathology of the spinal cord, which occurs as a result of the penetration of a viral infection into the body (pneumococcus, meningococcus). It is accompanied by a number of characteristic symptoms and, if left untreated, can lead to serious complications and even death of the patient.
Arachnoiditis. An inflammatory process develops in the lumbar region of the spinal cord, which also affects the membranes. All three levels suffer. Clinically, the disease manifests itself with focal symptoms and neurasthenic disorders.

The shells or the space between them can also be damaged as a result of injury. Usually these are bruises or fractures that cause compression of the spinal cord. Acute disruption of cerebrospinal fluid circulation causes paralysis or hydrocephalus. Many malfunctions of the membranes in the clinical picture can be confused with other infectious diseases, therefore an MRI is always prescribed to clarify the diagnosis.

Features of treatment

Inflammatory processes in the membranes of the spinal cord or brain require immediate treatment in a hospital setting. Self-medication of any disease at home often leads to death or serious complications. Therefore, when the first signs of illness appear, you should consult a doctor and follow all recommendations.

Features of treatment of possible pathologies:

Viral infection. Monitor body temperature and take enough fluids. If a person cannot drink a lot of water, droppers with saline solution are prescribed. If cysts form or the volume of cerebrospinal fluid increases, then medication is required to normalize the pressure. The chosen tactics to combat inflammation are adjusted as the patient’s condition improves.
Injury. The membranes of the spinal cord provide its normal nutrition and blood circulation, therefore, when scars, adhesions and other damage form, this function is disrupted, the movement of cerebrospinal fluid is hampered, which leads to the appearance of cysts and intervertebral hernia. Treatment in this case includes taking a set of medications to improve metabolic processes. If traditional therapy is ineffective, surgical intervention is prescribed.
Infectious processes. The entry of pathogenic bacteria into the organ requires the prescription of antibiotics. In most cases, this is a broad-spectrum drug. An important point is also monitoring water balance and body temperature.

The consequences of diseases of the membranes can be unpredictable. Inflammatory processes cause disturbances in the functioning of the body, fever, vomiting, seizures, and convulsions. Often hemorrhages lead to paralysis, which makes a person disabled for life.

The spinal membranes form a single system and are directly connected to the hypothalamus and cerebellum. Violation of their integrity or inflammatory processes lead to a deterioration in the general condition. Usually accompanied by seizures, vomiting, and fever. Modern medicine has reduced the mortality rate due to such diseases to 10–15%. But the risk still exists. Therefore, when you notice the first signs, you should immediately consult a doctor.

The spinal cord is covered with three connective tissue membranes, meninges. These shells are as follows, if you go from the surface inwards: hard shell, dura mater; arachnoid membrane, arachnoidea, and soft membrane, pia mater. Cranially, all 3 membranes continue into the same membranes of the brain.

The hard shell of the spinal cord, dura mater spinalis, covers the outside of the spinal cord in the form of a sac. It does not adhere closely to the walls of the spinal canal, which are covered with periosteum. The latter is also called the outer layer of the dura mater. Between the periosteum and the dura mater there is the epidural space, cavitas epiduralis. It contains fatty tissue and venous plexuses, plexus vendsi vertebrales interni, into which venous blood flows from the spinal cord and vertebrae.

Cranially, the hard shell fuses with the edges of the large foramen of the occipital bone, and caudally ends at the level of the II-III sacral vertebrae, tapering in the form of a thread, filum diirae matris spinalis, which is attached to the coccyx.

The arachnoid membrane of the spinal cord, arachnoidea spinalis, is represented by thin crossbars in the subdural space, spatium subdurale. Between the arachnoid membrane and the soft membrane directly covering the spinal cord there is a subarachnoid space, cavitas subarachnoidalis, in which the brain and nerve roots lie freely, surrounded by a large amount of cerebrospinal fluid, liquor cerebrospinalis. Cerebrospinal fluid is collected from this space for analysis. This space is especially wide in the lower part of the arachnoid sac, where it surrounds the cauda equina of the spinal cord (cisterna terminalis). The fluid filling the subarachnoid space is in continuous communication with the fluid of the subarachnoid spaces and ventricles of the brain.

Between the arachnoid membrane and the pia mater covering the spinal cord in the posterior cervical region, along the midline, a septum, septum cervie ale intermedium, is formed. In addition, on the sides of the spinal cord in the frontal plane there is a dentate ligament, ligamentum denticulatum, consisting of 19-23 teeth passing in the spaces between the anterior and posterior roots. The dentate ligaments serve to hold the brain in place, preventing it from stretching out in length. Through both ligg. denticulatae, the subarachnoid space is divided into anterior and posterior sections.

The soft shell of the spinal cord, pia mater spinalis, covered on the surface with endothelium, directly envelops the spinal cord and contains vessels between its two layers, together with which it enters its grooves and the medulla, forming perivascular spaces around the vessels.

Conclusion

The spinal cord is a section of the central nervous system of vertebrates and humans, located in the spinal canal; More than other parts of the central nervous system, it retained the features of the primitive brain tube of chordates. The spinal cord has the shape of a cylindrical cord with an internal cavity (spinal canal); it is covered with three meninges: soft or vascular (internal), arachnoid (middle) and dura (external), and is held in a constant position by ligaments running from the membranes to the inner wall of the bone canal. The space between the pia mater and arachnoid membrane (subarachnoid) and the brain itself, like the spinal canal, is filled with cerebrospinal fluid. The anterior (upper) end of the spinal cord passes into the medulla oblongata, the posterior (lower) into the filum terminale.

The spinal cord is conventionally divided into segments based on the number of vertebrae. A person has 31 segments: 8 cervical, 12 thoracic, 5 lumbar, 5 sacral and 1 coccygeal. From each segment a group of nerve fibers departs - radicular filaments, which, when connected, form the spinal roots. Each pair of roots corresponds to one of the vertebrae and exits the spinal canal through the opening between them. The dorsal spinal roots carry sensitive (afferent) nerve fibers through which impulses from receptors in the skin, muscles, tendons, joints, and internal organs are transmitted to the spinal cord. The anterior roots contain motor (efferent) nerve fibers, through which impulses from motor or sympathetic cells of the spinal cord are transmitted to the periphery (to skeletal muscles, vascular smooth muscles and internal organs). The posterior and anterior roots unite before entering the intervertebral foramen, forming mixed nerve trunks as they exit the spine.

The spinal cord consists of two symmetrical halves connected by a narrow bridge; Nerve cells and their short processes form the gray matter around the spinal canal. The nerve fibers that make up the ascending and descending tracts form white matter at the edges of the gray matter. The outgrowths of the gray matter (anterior, posterior and lateral horns) divide the white matter into three parts - the anterior, posterior and lateral cords, the boundaries between which are the exit points of the anterior and posterior spinal roots.

The activity of the spinal cord is reflexive in nature. Reflexes arise under the influence of afferent signals entering the spinal cord from receptors that are the beginning of the reflex arc, as well as under the influence of signals going first to the brain and then descending to the spinal cord along the descending pathways. The most complex reflex reactions of the spinal cord are controlled by various centers of the brain. In this case, the spinal cord serves not only as a link in the transmission of signals coming from the brain to the executive organs: these signals are processed by interneurons and combined with signals arriving at the same time from peripheral receptors.