Spinal cord: structure and function

Human spinal cord - anatomy, structure and function

The human spinal cord is the most important organ of the central nervous system, which connects all organs to the central nervous system and conducts reflexes.

It is covered from above with three shells: solid, arachnoid and soft.

Between the arachnoid and the soft (vascular) membrane and in its central canal there is a spinal fluid (cerebrospinal fluid)

In the epidural space (the space between the dura mater and the vertebral column) - the vessels and fatty tissue

Structure and function of human spinal cord

What is the spinal cord of the external structure?

It is a long cord in the vertebral canal, in the form of a cylindrical strand, about 45 mm long, about 1 cm wide, more flat at the front and behind than at the sides. It has a conditional upper and lower bound.

The upper one begins between the line of the large occipital foramen and the first cervical vertebra: at this point the spinal cord joins the head with an intermediate oblong vertebra.

Lower - at the level of 1 -2 lumbar vertebrae, after which the cord assumes a conical shape and then "degenerates" into thin spinal cord (terminal) with a diameter of about 1 mm, which extends to the second vertebra of the coccygeal department. Terminal thread consists of two parts - internal and external:

• internal - about 15 cm long, consists of nerve tissue, interlaced with lumbar and sacral nerves and is in a bag of dura mater
• external - about 8 cm, starts below the second vertebra of the sacral region and extends as a junction of hard, arachnoid and soft membranes to the second coccygeal vertebra and fuses with the periosteum

The external terminal thread, hanging down to the coccyx, with intertwining nerve fibers, resembles the pony tail in appearance. Therefore, the pains and phenomena that occur when the nerves are clamped below the second sacral vertebra are often called horse tail syndrome.

The spinal cord has thickenings in the cervical and lumbosacral divisions. This finds its explanation in the presence of a large number of outgoing nerves in these places going to the upper, as well as to the lower limbs:

1. Neck enlargement extends from the 3rd to 4th cervical vertebrae to the 2nd thoracic vertebra, reaching a maximum in the 5th to the 6th
2. Lumbosacral - from the level of the 9th - 10th thoracic vertebrae to the 1 st lumbar with a maximum in the 12th thoracic

Gray and white matter of the spinal cord

If you consider the structure of the spinal cord in a cross-section, then in the center of it you can see a gray patch in the form of a butterfly that has opened its wings.

This is the gray matter of the spinal cord. It is surrounded by a white substance outside.

The cellular structure of gray and white matter is different, as are their functions.

The gray matter of the spinal cord consists of motor and intercalary neurons:

• motor neurons transmit motor reflexes
• interlaced - provide a link between the neurons themselves

The white matter consists of the so-called axons - nerve processes, from which fibers of descending and ascending conducting paths are created.

The wings of the "butterfly" are narrower forming the front horns of gray matter, the wider ones are the rear ones. In the anterior horns there are motor neurons, in the hind ones - intercalary neurons.

Between the symmetrical lateral parts there is a transverse bridge from the brain tissue, in the center of which passes the canal, which is connected by the upper part with the ventricle of the brain and filled with cerebrospinal fluid.

In some departments or even the entire length of adults, the central canal can overgrow.

Concerning this channel, to the left and to the right of it, the gray matter of the spinal cord looks like pillars of a symmetrical shape, connected by front and rear spikes:

• Front and rear posts correspond to the front and rear horns on the cross section
• lateral ledges form a lateral column

Lateral protrusions are not on all extent, but only between the 8th cervical and the 2 nd lumbar segments. Therefore, the transverse section in segments where there are no lateral protrusions, has an oval or round shape.

The connection of symmetrical columns in the anterior and posterior parts forms two furrows on the surface of the brain: anterior, deeper, and posterior. The front slit ends with a septum adjacent to the back edge of the gray matter.

Spinal nerves and segments

Left and right of these central furrows are respectively the anterolateral and posterolateral fissures, through which the anterior and posterior strands (axons) form the nerve roots.

The anterior spine in its structure is the motor neurons of the anterior horn. Rear, responsible for sensitivity, consists of intercalary neurons of the rear horn.

Immediately at the exit from the marrow segment, both the anterior and posterior root are combined into one nerve or nerve node (ganglion).

To do this, consider its segmental structure. There are 31 segments in total:

• 8 - in the cervical section
• 12 - in the thoracic
• 5 - lumbar
• 5 - in the sacral
• 1 - in the coccygeal

So the spinal cord has only 62 nerves - 31 on each side.

The departments and segments of the spinal cord and spine are not on the same level, due to the difference in length (the spinal cord is shorter than the spine).

This should be taken into account when comparing the cerebral segment and the vertebra number when performing radiology and tomography: if at the beginning of the cervical region this level corresponds to the vertebra number, and in the lower part it lies on the vertebra above, then in the sacral and coccygeal department this difference is already several vertebrae.

Two important functions of the spinal cord

The spinal cord performs two important functions - the reflex and the conductor. Each of its segments is associated with specific bodies, ensuring their functionality. For example:

• Cervical and thoracic parts - communicates with the head, hands, chest, chest muscles
• Lumbar department - organs of the digestive tract, kidneys, muscular system of the trunk
• Sacral section - pelvic organs, legs

Reflex functions are simple, natural reflexes. For example:

• painful reaction - pull your arm away if it hurts.
• knee-jerk

This is proved by simple experiments on animals. Biologists conducted experiments with frogs, testing how they react to pain in the absence of the head: a response was observed to both weak and strong pain stimuli.

Thanks to this conductor connection, any mental action is carried out:
stand up, go, take, throw, raise, run, cut, draw - and many others that a person, without noticing, commits in his daily life in everyday life and at work.

Such a unique connection between the central brain, the dorsal, the entire CNS and all organs of the body and its limbs, as before remains the dream of robotics.

None, even the most modern robot is yet able to implement and a thousandth part of all kinds of movements and actions that are subject to the bioorganism.

As a rule, such robots are programmed for narrowly specialized activities and are mainly used in conveyor automatic production.

Functions of gray and white matter.To understand how these magnificent functions of the spinal cord are carried out, let us consider the structure of the gray and white matter of the brain at the cellular level.

The gray matter of the spinal cord in the anterior horns contains large nerve cells called efferent (motor) cells and are combined into five cores:

• central
• anterolateral
• posterolateral
• anteromedial and posteromedial

The sensory roots of the small cells of the posterior horns are specific cell processes from the sensitive nodes of the spinal cord. In the posterior horns, the structure of the gray matter is not uniform.

Most of the cells form their own nuclei (central and thoracic).

To the border zone of the white matter, located near the hindbusts, there are spongy and gelatinous areas of gray matter, the processes of the cells of which, together with the processes of small diffuse-scattered cells of hind horns, form synapses (contacts) with the neurons of the anterior horns and between adjacent segments. These neurites are called front, lateral and posterior intrinsic bundles. Their connection with the brain is carried out with the help of white matter conductors. At the edge of the horns, these bundles form a white border.

The side horns of gray matter perform the following important functions:

• In the intermediate zone of gray matter (lateral horns) there are sympathetic cells of the autonomic nervous system, it is through their communication with the internal organs. The processes of these cells are connected to the front roots
• Here the spinal cord is formed: the level of the cervical and upper thoracic segments is the reticular zone - a bundle of a large number of nerves associated with the activation zones of the cerebral cortex and the reflex activities.

Conducting functions of white matter are carried out by means of three cables - its outer areas, limited furrows:

• Anterior cord is the area between the anterior median and lateral grooves
• The back cord is between the posterior median and lateral grooves
• Lateral cord - between anterolateral and posterolateral grooves

The axons of white matter form three systems of conductivity:

• short beams, called associative fibers, that bind different segments of the spinal cord
• ascending sensitive (afferent) beams directed towards the brain regions
• descending motor (efferent) bundles directed from the brain to the neurons of the gray substance of the anterior horns

Ascending and descending conduction paths.Consider, for example, some functions of the paths of the white matter cochains:

Front cables:

• Anterior pyramidal (cortico-spinal) path- transmission of motor impulses from the cerebral cortex to the spinal cord (anterior horns)
• Spinalateral anterior path- transmission of impulses of tactile impact on the surface of the skin (tactile sensitivity)
• Spinal cord and spinal cord- By linking the visual centers under the cerebral cortex with the cores of the anterior horns, creates a protective reflex caused by sound or visual stimuli
• The bundle of Geld and Levental (the pre-spinal cord)- White matter fibers bind the vestibular nuclei of eight pairs of cranial nerves with motor neurons of the anterior horns
• Longitudinal posterior fascicle- linking the upper segments of the dorsal with the trunk of the brain, coordinates the work of the eye muscles with the cervical, etc.

The ascending paths of the lateral cordage impart a pulse of deep sensitivity (sensation of one's body) along the cortical-spinal, spinotalamic, and spinal-spinal pathways.

Descending ways of lateral cord:

• Lateral cortico-spinal (pyramidal)- transmits the impulse of movement from the cortex of the brain to the gray matter of the anterior horns
• The cerebro-spinal cord(located in front of the lateral pyramidal), from the side of it lie the spinal cord and spinalateral lateral path. The cerebro-spinal cord provides automatic control of movements and muscle tone at a subconscious level.

In different parts of the spinal cord a different ratio of gray and white medulla. This is explained by the different number of ascending and descending ways. In the lower cerebrospinal segments there is more gray matter.

As it moves upward, it becomes smaller, and the white matter is added on the contrary, since new upward pathways are added, and at the level of the upper cervical segments and the middle part of the pectoral white - most.

But in the region of both cervical and lumbar thickenings, gray matter predominates.

As you can see, the spinal cord has a very complex structure.

The connection of nerve bundles and fibers is vulnerable, and a serious injury or illness can disrupt this structure and lead to disturbance of the conductive pathways, which can lead to complete paralysis and loss below the "break" point of conductivity sensitivity. Therefore at the slightest dangerous signs the spinal cord should be examined and treated on time.

Puncture of the spinal cord

For the diagnosis of infectious diseases (encephalitis, meningitis, etc.) diseases), spinal cord puncture (lumbar puncture) is used - the needle is guided into the spinal canal.

It is conducted in this way:
In the subarachnoid space of the spinal cord at the level below the second lumbar vertebra, a needle is inserted and the spinal fluid (CSF) is taken.

This procedure is safe, because below the second vertebra in an adult human spinal cord is absent, and therefore there is no threat of damage to it.

Puncture of the spinal cord is carried out not only for diagnosis, but also for treatment, in such cases:

• the introduction of chemotherapeutic drugs or antibiotics under the shell of the brain
• for epidural anesthesia during surgery
• for treatment of hydrocephalus and reduction of intracranial pressure (removal of excess CSF)

Puncture of the spinal cord has such contraindications:

• spinal canal stenosis
• dislocation
• dehydration

Take care of this important organ, do elementary prevention:

1. Take antiviral drugs during an epidemic of viral meningitis
2. Try not to make picnics in the forest park in May-early June (the period of activity of the encephalitis tick)
3. After each trip to the forest, inspect the whole body, and at the first signs of illness go to the doctor. Symptoms are: headache, high fever, neck stiffness (difficulty of movement), nausea.

A source: https://ZaSpiny.ru/raznoye/spinnoy-mozg.html

Structure and functions of the spinal cord

The spinal cord is a complex and multifaceted organ in the nervous system.

In humans, it is controlled and controlled by the centers of the brain and has an addictive character. The human spine protects the brain substance from external influences.

The spinal cord performs two functions. Let's take a closer look at exactly what functions it performs.

Characteristics of the organ

The morphofunctional characteristic of the dorsal organ is as follows:

The spinal cord consists of two symmetrical halves, separated by a deep median slit. Behind them separates the connective tissue partition.

Inside, the organ has a dark area, which is called a gray matter. In the periphery of the spinal cord is a light white substance.

On the side of the cross section, the organ has an H-shaped gray matter. The places in which the gray substance acts are called horns. They can be anterior (ventral), posterior (dorsal) and lateral (lateral).

The gray matter includes bodies of neurons, demyelin and thin myelin fibers, as well as neuroglia. It differs from white matter in that it has multipolar neurons in its composition.

Longitudinal myelinated fibers are a white substance. Nerve fibers, which connect different parts of the nervous system, consist of the conductive pathways of the spinal cord.

Organ neurons are divided into neurites, radicular cells, as well as internal and fascicle neurons.

Each posterior horn includes a spongy layer, a gelatinous substance, a horn core and a thoracic nucleus.

The anterior horns are equipped with large neurons of the spinal cord, which form nuclei-somatic centers, also they have medial and lateral groups of motor cells. The medial cells are responsible for the functioning of the muscles of the trunk of the person, and the lateral muscles are the muscles of the arms and legs.

What does the organ consist of?

The spinal cord has round sections, but its structure also includes thickened areas that have a flattened shape from front to back.

Neck thickening can be seen near the third cervical and first thoracic vertebra. In the area of ​​10 - 12 thoracic vertebrae is a lumbosacral thickening.

In the field of somatic neurons, which are located in the thickening of the organ, there are many roots with a large number of nerve fibers.

The thickness of somatic neurons is greatest, since they are larger than other neurons.

The spinal cord supplies the internal organs and the human skeletal musculature with nerve fibers that bind to the central nervous system. The valuable organ of the spine consists of 31 segments, which are responsible for different organs and parts of the body:

For the head, neck, thoracic cavity, heart, lungs and arms, eight cervical segments meet.

12 thoracic and 5 vertebral segments are responsible for the abdominal cavity and muscles of the trunk.

Spinal-medullary fluid can be seen in the canal, which is located in the center of the dorsal organ.

Functions of the body

Thanks to the reflex center, the organ can perform different reflexes. Sensitive impulses through the cerebrospinal canal penetrate the brain, transmit information about the state of work of all spheres in the human body.

Consequences - with the help of descending pathways, the impulses that the brain sends are transmitted to the insensitive neurons of the spinal cord. They activate them and control the work of neurons.

Reflex function

The organ performs a reflex function: it is responsible for the motor and sensory reflexes in the human body. Thanks to the nerve channels, the spinal cord on both sides connects the peripheral organs with the brain.

The substance that is in the canal of the spine, sends the appropriate signals to the brain. They convey information about the effect on the human body of external and internal factors of the environment.

With the help of the transmission of autonomic reflexes, the CNS organ changes the functioning of internal life support systems.

The motor function of the spinal cord carries out and regulates the musculature reflexes of the system of motion. Neurons that refer to the spinal cord impart impulses to the muscles that are in the area of ​​the arms, legs, body and neck.

The central nervous system, located in the canal of the spine, takes part in the organization of all human movements.

Conductor function

The structure of the spinal cord allows for the uninterrupted transmission of impulses through parallel paths to the cerebral cortex of the brain. Some signals are carried out through a short path, and the second signals through a long one.

Through the transfer of impulses and reflexes between the organs of the entire human body, he is able to perceive information and perform the necessary actions.

Therefore, the reflex and conductor functions are closely related to each other and are very important for humans.

If the brain is squeezed or injured, a spinal shock occurs. Because of this, the excitability of the nervous reflexes in the center decreases sharply, the work of the nervous system slows down. With spinal shock, the factors that aroused reflexes become ineffective.

Consequences, if the dorsal canal of the cervical, thoracic or other department is damaged, are as follows:

1. Skeletal motor and autonomic reflexes are lost.
2. The pressure decreases.
3. There are no vascular reflexes.
4. Violated ability to go to the toilet.

Such consequences are dangerous for human life, therefore the victim should be immediately shown to the doctor for the necessary medical care.

What happens if the functions are violated?

The spinal cord can rupture or atrophy. In any situation, the patient needs to be rushed to the hospital.

Rupture of organ

When the organ is ruptured, very unpleasant, severe and unpredictable consequences can occur.

When the brain ruptures, sensitivity, activity of a person is lost, partial or complete paralysis of the body may occur.

Such a break occurs when you receive a domestic trauma, when you fall from a height or get into a car accident. If the whole body refuses to work, a spinal shock occurs, which often leads to the death of a person.

Atrophy of the organ

With the atrophy of the spinal cord, nerve fibers and cells gradually die out, which causes the breakdown of nerve connections. Any part of the spine can atrophy.

This phenomenon often occurs in women after 50 years. They become weak-minded. If the disease is diagnosed in children, it means that it was inherited.

Consequences in the form of atrophy of the dorsal organ depend on what his department suffered. At first the person becomes less active and listless.

Then the moral norms are ignored. After that, problems with memory, speech, sense organs, and motor skills begin.

The person stops analyzing and expressing his opinion.

To reduce the consequences and help a person with an atrophied brain to live on, it is recommended to treat it with vitamins and vascular preparations.

Also for the sick people, the care and love of others is important. It is necessary for a person to take an active part in his life.

It should be directed to a certain track, monitor its regime, nutrition and health.

As you can see, the spinal cord takes part in the management of the whole body, as well as in the transfer of information from external factors to the relevant bodies, so that they fulfill their functions.

It is important to protect the body, to treat diseases in a timely manner and to monitor your health carefully.

Proper nutrition, active lifestyle, observance of care measures, good mood will help the spinal cord function better.

A source: http://drpozvonkov.ru/pozvonochnik/medullae-spinalis/spinnoy-mozg-funktsii.html

Spinal cord - where located, length and segments, risk of injury and injury

The organ of the central nervous system is the spinal cord, which performs special functions and has a unique structure.

It is located in the spine, in a special canal, directly connected to the brain.

Functions of the organ - conductor and reflex activity, it ensures the work of all parts of the body at a given level, transmits impulses and reflexes.

What is the spinal cord?

The Latin name for the brain is the spinal medulla spinalis. This central organ of the nervous system is located in the vertebral canal.

The border between him and the brain passes approximately at the intersection of pyramidal fibers (at the nape of the neck), although it is conditional. Inside there is a central canal - the cavity, protected by a soft, arachnoid and dura mater.

Between them is the cerebrospinal fluid. The epidural space between the outer shell and the bone is filled with fat tissue and a vein net.

There is an organ inside the vertebral canal from the first cervical vertebra to the second lumbar, preserving the curvature.

Above it begins with an oblong section - at the occiput, and at the bottom - ends with a conical point, an end thread from the connective tissue.

The organ is characterized by longitudinal segmentation and the significance of the links: the anterolateral sulcus extends the anterior radicular filaments (axons of nerve cells), forming the anterior motor spine, serving to transmit motor impulses. Rear radicular filaments form a posterior spine, which conducts pulses from the periphery to the center. The lateral horns are provided with motor, sensitive centers. Spines create a spinal nerve.

Length

In an adult, the organ is 40-45 cm in length, 1-cm in width, 35 g in weight.

It increases in thickness from the bottom up, the largest diameter reaches the upper cervical region (up, cm) and the lower lumbosacral (up, cm).

In the chest area, the diameter is 1 cm. The organ is divided into four surfaces:

• Flattened front;
• convex posterior;
• two rounded lateral.

Appearance

On the front surface along the entire length lies the median slit, which has a fold of the medulla - an intermediate cervical septum.

Behind the middle groove, connected with a plate of glial tissue, is isolated. These cracks divide the spinal column into two halves, connected by a narrow bridge of tissue, in the center of which is the central canal.

From the sides, too, there are furrows - anterolateral and posterolateral.

Segments of the spinal cord

The departments of the spinal cord are divided into five parts, the significance of which does not depend on the location, but on the part in which the leaving nerves leave the vertebral canal. In total, a person can have 31-33 segments, five parts:

• neck segment - 8 segments, at its level greater than gray matter;
• thoracic - 12;
• lumbar - 5, the second area with a large amount of gray matter;
• sacral - 5;
• coccygeal - 1-3.

Gray and white matter

On the cut of the symmetrical halves, there is a deep median slit, a connective tissue partition. The inner part is darker - it's a gray matter, and on the periphery of the lighter - a white substance.

On the cross-section, the gray matter is represented by a pattern of "butterfly and its protrusions resemble horns (anterior ventral, posterior dorsal, lateral lateral). Most of all gray matter on the lumbar region, less - on the chest.

At the medulla cone the entire surface is gray, and on the periphery there is a narrow layer of white.

What is formed by the gray matter of the spinal cord - it consists of the bodies of nerve cells with processes without myelin sheath, thin myelin fibers, neuroglia. The basis is multipolar neurons. The cells lie inside the nucleus groups:

• radicular - axons leave as part of the anterior roots;
• internal - their processes terminate in synapses;
• beam - axons pass to the white matter, carry nerve impulses, form conductive paths.

Between the hind and side horns, gray flows into the interior of the white, forming a net-like loosening - net formation.

Functions of gray matter of the central nervous system are: transmission of pain impulses, information on temperature sensitivity, closure of reflex arches, obtaining data from muscles, tendons and ligaments. Neurons of the anterior horns participate in the connection of the departments.

White matter functions

A complex system of myelin, demyelinic nerve fibers is the white matter of the spinal cord.

There is a supporting neural tissue - neuroglia, plus blood vessels, a small amount of connective tissue. Fibers are collected by bundles, which perform connections between segments.

White matter surrounds the gray, conducts nerve impulses, performs mediation.

Functions of the spinal cord

The structure and functions of the spinal cord are directly related. There are two important tasks of the organ - reflex, conductor.

The first is the fulfillment of the simplest reflexes (withdrawal of the hand during a burn, extension of the joints), and connections with skeletal muscles.

The conductor transmits impulses from the spinal cord to the brain, back along the ascending and descending paths of motion.

Reflex

In the response of the nervous system to stimulation, a reflex function consists. It includes withdrawal of the hand when pricking, coughing when foreign particles enter the throat.

Irritation from the receptors by the pulse enters the spinal canal, switches the motor neurons that are responsible for the muscles, cause their contraction.

This is a simplified scheme of the reflex ring (arc) without the involvement of the brain (a person does not think when performing an action).

Define reflexes congenital (sucking, breathing) or acquired. The first help to identify the correct operation of the elements of the arc, the segments of the organ. They are checked for neurologic examination.

The knee, abdominal, plantar reflex is mandatory for testing human health.

These are superficial species, the deep reflexes include the flexor-ulnar, knee, and Achilles.

Conductor

The second function of the spinal cord is the conductor, which transmits impulses from the skin, mucous membranes and internal organs to the brain, in the opposite direction. White matter serves as a conductor, carries information, an impulse about the impact from the outside.

Due to this, a person receives a certain feeling (soft, smooth, slippery object). With loss of sensitivity, sensations from touching anything can not be formed.

In addition to commands, pulses transmit data about the position of the body in space, pain, muscle tension.

What organs of man control the work of the spinal cord

Responsible for the spinal canal and the management of all the work of the spinal cord is the main organ of the central nervous system - the brain.

Assistants are numerous nerves and blood vessels. The brain has a great influence on the activity of the spinal cord - it controls walking, running, labor movements.

With the loss of communication between organs, a person at the end practically becomes helpless.

Danger of injury and injury

The spinal cord connects all the systems of the body. Its structure plays an important role in the proper operation of the musculoskeletal system.

If it is damaged, there will be a spinal trauma, the severity of which depends on the extent of the damage: stretching, ligament rupture, dislocations, damage to the discs, vertebrae, processes - light, medium.

To severe carry fractures with displacement and multiple damage to the canal itself. This is very dangerous, leading to a disruption in the functionality of the ropes and paralysis of the lower extremities (spinal shock).

Computer-resonance tomography can detect trauma. For the treatment of light bruises and damage to the zones can be used by medicines, medical gymnastics, massage, physiotherapy.

Heavy options need surgery, especially diagnosing compression (rupture - cells die instantly, there is a risk of disability).

The consequences of traumatizing the spinal cord are a long recovery period (1-2 years), which can be accelerated by acupuncture, ergotherapy and other interventions.

After a serious case, there is a risk of returning the motor ability not completely, and sometimes permanently stay in a wheelchair.

A source: http://sovets.net/13201-spinnoj-mozg.html

The structure of the spinal cord: the scheme, departments and functions

The spinal cord is a part of the central nervous system of man, its main components are nerve cells. They are located in the canal of the spine and perform many functions.

This body has a similarity with the cylinder, it originates near the human brain, and ends in the region of the waist. Thanks to him in the body there are such processes as palpitation, breathing, digestion and even urination.

Consider the structure of the spinal cord.

External structure of the spinal cord

Due to its shape and appearance resembling a cylinder, this organ can be called an elongated pull. Its average length for men is approximately 45 cm, and for women about 42 cm.

This body has good protection, since it is surrounded by a solid, arachnoid and soft shells. In this case, the interval between the arachnoid and soft membranes contains spinal fluid.

The following sections of the spinal cord stand out that correspond to the human spine sections:

• cervical;
• thoracic;
• lumbar;
• sacral;
• coccygeal.

The spinal cord goes from the brain itself, where the lower edge of the occipital opening is located, and ends in the lumbar spine. Its diameter is usually 1 cm.

This organ has thickenings in two places, they are located in the cervical and lumbar spinal cord, namely in these thickenings there are nerve cells, the processes of which are directed both to the upper and lower limbs.

On the front surface of this organ in the middle is the median slit, and on its rear surface in the center is located the posterior median furrow.

From her and up to the grayest substance along all its length the back median septum flows. On the surface of its lateral part one can see the anterolateral and posterolateral fissures, they go from top to bottom along the entire length of this organ.

Thus, the anterior and posterior furrows divide this organ into 2 symmetrical parts.

This body is divided into 31 parts, which are called segments. Each of them consists of the front and back roots. It is the posterior roots of this CNS organ that contain sensory nerve cells located in the spinal nodes.

The front roots are formed when the neuron exits the brain. The posterior roots arise from the nerve fibers of the afferent neurons.

They are sent to the so-called rear horns of this gray substance, and there, with the help of efferent neurons, the front roots appear, which, merging, form a spinal nerve.

The structure of the spinal cord is quite complex, but it provides the preservation of nerve cells. In addition to external components, this CNS organ also has an internal structure.

Internal structure

Gray and white matter together form all the conductive pathways of the spinal cord. They represent its internal composition. The gray matter is located in the center, and the white matter is located along the entire periphery.

Gray matter is formed as a result of the accumulation of short processes of neural cells and consists of 3 protuberances, which form gray columns.

They are located along the entire length of this organ and in a section form:

• Front horn, which contains large motor neurons;
• The horn produced by small neurons that promote the appearance of sensitive posts;
• side horn.

The gray matter of this organ of the nervous system presupposes the presence of the kidney cells. They, located along the entire length of the gray matter, form beam cells, which conduct connections between all segments of the dorsal bridge.

The main part of the white matter is formed by long processes of neurons having a myelin sheath, which gives a white shade to the neurons.

White matter on both sides of the spinal cord is associated with a white solder.

The neurons of the white matter of the spinal cord are collected in special bundles, they are delimited with 3 grooves into 3 cord of the spinal cord.

Of course, white and gray substances together do not have a homogeneous structure, but they form a relationship among themselves, through which nerve impulses from the central nervous system to all peripheral nerves are transmitted.

Because of this close connection with the brain, many doctors do not share these two components of the human nervous system, since they consider them to be one.

Therefore, it is very important to take care of preserving their functions, which are vital for every person.

What functions does the body perform?

Despite the complexity of the structure of this organ, only 2 functions of the spinal cord are distinguished:

• reflex;
• conductor.

The reflex function is that, in response to environmental irritations, the body reacts depending on the situation.

For example, if you unintentionally touch a hot iron, then the reflex of the body will immediately pull back the hand, or when a person chokes with something, a cough arises immediately.

Thus, the usual actions that are of great benefit to the body are due to the operation of the spinal cord. How do reflexes of the spinal cord arise? This process takes place in several stages.

It can be considered with the example of a hot iron:

1. Due to skin receptors that have the properties of perceiving hot and cold objects, impulses move along the peripheral fibers to the spinal cord itself.
2. Then this impulse penetrates into the horns and switches one neuron to another.
3. After this, a small process of the neuron passes into the anterior horns, where it becomes a motor neuron and is responsible for the movement of the muscles.
4. The motor neurons come out of the spinal cord together with the nerve that goes to the arm.
5. The impulse that this object is hot, with the help of a contraction of the muscles of the hand helps to pull away from the hot object.

Such actions are called a reflex ring, it is thanks to him that there is a response to an unexpectedly appeared stimulus. Thus such reflexes of a spinal cord can be both congenital, and got.

They can be purchased throughout life.

The spinal cord, whose structure and functions are very complex, has a huge number of neurons that help coordinate the activity of all available structures of the spinal cord, thereby forming sensations and inducing movement.

As for the conductor function, it transmits impulses to the brain and back to the spinal cord.

Thus, the brain receives information about various environmental influences, while the person has pleasant or, conversely, unpleasant sensations.

Therefore, the functions of the spinal cord perform one of the main roles in human life, since they are responsible for sensitivity and sense of smell.

What are the possible diseases?

Since this body regulates the transfer of impulses to all systems and organs, the main sign of a violation of its activities is a loss of sensitivity.

Due to the fact that this body is part of the CNS, the diseases are associated with neurological features.

Usually, various lesions of the spinal cord cause such symptoms:

• disorders in limb movement;
• pain syndrome of cervical and lumbar spine;
• impaired sensitivity of the skin;
• paralysis;
• urinary incontinence;
• loss of muscle sensitivity;
• increase in temperature in affected areas;
• pain in the muscles.

These symptoms can develop in different sequences, based on the area in which this lesion is located. Depending on the causes of the disease, there are 3 groups:

1. All kinds of malformations, including postpartum. The most common congenital anomalies.
2. Diseases that involve circulatory disorders or various tumors. It happens that such pathological processes cause and hereditary diseases.
3. All kinds of injuries (bruises, fractures) that disrupt the operation of the spinal cord. These can be injuries as a result of car accidents, falls from height, household or as a result of bullet or stab wounds.

Any spinal cord injury or diseases that cause such consequences are very dangerous, because they often deprive many people of the opportunity to walk and live fully. You should contact your doctor as soon as possible to start treatment on time, if after the injury or illness the above symptoms or such violations are observed:

• loss of consciousness;
• deterioration of vision;
• frequent seizures;
• difficulty breathing.

Otherwise, the disease can progress and cause such complications:

• chronic inflammatory processes;
• disruption of the gastrointestinal tract;
• a violation in the work of the heart;
• circulatory disturbance.

Therefore, you should seek help from a doctor in time to get the right treatment. Because of this, you can save your sensitivity and protect yourself from pathological processes in the body that can lead to a wheelchair.

Diagnosis and treatment

Any injury to the spinal cord can have a terrible impact on human life. Therefore, it is so important to know about the proper treatment.

First of all, all people who seek help with such symptoms should undergo diagnostic tests that will determine the extent of the lesion.

Among the most common and accurate methods of research are the following:

1. Magnetic resonance imaging, which is the most informative procedure. It can diagnose the level of complexity of injuries, arthrosis, hernias, tumors and bruises.
2. Radiography. It is a diagnostic method that helps to identify only such damages as fractures, dislocations and displacement of the spine.
3. CT scan. It also shows the nature of the damage, but does not have a general visualization of this organ.
4. Myelography. This method is mainly intended for those who can not for any reason make an MRI. This study is the introduction of a special substance, through which you can find the causes of the disease.

After the study, the most suitable treatment for each individual patient is prescribed. However, there are situations when the pathology occurred as a result of a fracture. Such treatment must begin with the provision of first aid.

It consists in the release of clothing or objects on the affected area of ​​the body. It is very important that in this case the patient fully receives air and there are no obstacles to breathing. After this, you should expect the arrival of an ambulance.

Depending on the nature of the lesion, this disease can be treated both medically and surgically. Medicamentous treatment is based on the intake of hormonal drugs, often with the addition of diuretics.

Another more serious method of treatment is surgical intervention. It is used when medication treatment does not bring the desired result.

Very often, the operation is performed with malignant tumors of the spine, including the spinal cord. More rarely this method is used in benign tumors, when they cause painful sensations or their treatment with drugs is impossible.

Therapy is prescribed exclusively by a specialist, self-medication in this case is dangerous.

A source: https://SoSpiny.ru/spinnoj-mozg/stroenie-i-funktsii-spinnogo-mozga.html