Spinal cord, its structure, functions, pathology in trauma, puncture

The spinal cord is an inseparable part, the whole department belonging to the central nervous system, originating in the brain. It is a white cord with a length of 45 cm and a diameter of about 1 cm. It is an extension of the medulla oblongata, the oldest structure.

Structure

The spinal cord is located in the vertebral canal. Behind and in front are two furrows, thanks to which the brain divides into the right and left half. It is covered with three shells: vascular, arachnid and solid. The space between the vascular and spider veins is filled with cerebrospinal fluid.

In the center of the spinal cord, you can see the gray matter, on the cut in shape resembling a butterfly. The gray matter consists of motor and intercalary neurons. The outer layer of the brain is a white substance of axons collected in descending and ascending conduits.

In gray matter, there are two types of horns: the front ones, in which the motor neurons are located, and the rear, the location of intercalary neurons.

The structure of the spinal cord has 31 segments. From each stretch the front and back roots, which, merging, form a spinal nerve. When you leave the brain, the nerves immediately fall into the roots - the back and the front. The posterior roots are formed by axons of afferent neurons and are directed into the posterior horns of gray matter. In this place they form synapses with efferent neurons, whose axons form the front roots of the spinal nerves.

In the posterior roots there are spinal nodes in which the sensory nerve cells are located.

The spinal cord passes through the spinal cord. To the muscles of the head, to the lungs, to the heart, to the organs of the thoracic cavity and the upper limbs, the nerves move away from the segments of the upper thoracic and cervical parts of the brain. The organs of the abdominal cavity and the muscles of the trunk are controlled by segments of the lumbar and thoracic parts. The muscles of the lower abdominal cavity and the muscles of the lower extremities are controlled by the sacral and lower lumbar segments of the brain.

Functions

There are two main functions of the spinal cord:

1. Conductor;
2. Reflective.

The conductor function is that the nerve impulses on the ascending brain paths move to the brain, and the descending paths from the brain to the working organs receive commands.

Reflex function of the spinal cord is that it allows you to perform simple reflexes( knee reflex, pulling the arm, flexing and unbending the upper and lower extremities, etc.).

Only simple motor reflexes are performed under the control of the spinal cord. All other movements, such as walking, running, etc., require compulsory involvement of the brain.

Pathologies, trauma, consequences

Based on the causes of spinal cord pathology, three groups of its diseases can be distinguished:

1. Developmental defects - postpartum or congenital abnormalities in the structure of the brain;
2. Diseases caused by tumors, neuroinfections, spinal cord injury, hereditary diseases of the nervous system ;
3. Spinal cord injuries , which include bruises and fractures, squeezing, tremors, dislocations and hemorrhages. They can appear both autonomously and in combination with other factors.

Any spinal cord disease has very serious consequences. To a special type of diseases can be attributed trauma to the spinal cord, which according to statistics can be divided into three groups:

1. Car accidents - are the most common cause of damage to the spinal cord. Especially traumatic is the driving of motorcycles, since there is no rear seat back, protecting the spine.
2. The fall from the height of - can be either accidental or willful. In any case, the risk of damage to the spinal cord is large enough. Often sportsmen, fans of extreme and jumping from the top get injured in this way.
3. Household and extraordinary injuries .Often they arise as a result of descent and fall in an unfortunate place, a fall from a ladder or ice. Also to this group include knife and bullet wounds and many other cases.

In spinal cord injuries, the conductor function is primarily disturbed, which leads to very disastrous consequences. For example, brain damage in the cervical region leads to the fact that the brain functions remain, but lose contact with most organs and muscles of the body, which leads to paralysis of the body. Similar disorders occur when peripheral nerves are damaged. If sensitive nerves are damaged, then sensitivity is disturbed in certain areas of the body, and damage to the motor nerves disrupts the movement of certain muscles.

Most nerves are of a mixed nature, and their damage causes both inability to move and loss of sensitivity at the same time.

Puncture, indications

Spinal puncture is to insert a special needle into the subarachnoid space. Spinal cord puncture is performed in special laboratories where the permeability of this organ is determined and the pressure of the CSF is measured.

Puncture is performed for both medical and diagnostic purposes. It allows to timely diagnose the presence of hemorrhage and its intensity, to find inflammatory processes in the meninges, to determine the nature of the stroke, to determine the changes in the character of the cerebrospinal fluid, signaling the diseases of the central nervous system.

Often puncture is done for the introduction of radiocontrast and medicinal fluids.

For therapeutic purposes, puncture is performed in order to extract blood or purulent fluid, as well as for administration of antibiotics and antiseptics. Indications for spinal cord puncture:

1. Meningoencephalitis;
2. Unexpected hemorrhages in the subarachnoid space due to aneurysm rupture;
3. Cysticercosis;
4. Myelitis;
5. Meningitis;
6. Neurosyphilis;
7. Craniocerebral injury;
8. Liquorrhea;
9. Echinococcosis.

Sometimes when performing operations on the brain, spinal cord puncture is used to reduce the parameters of intracranial pressure, as well as to facilitate access to malignant neoplasms.

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