Home / Description of the structure and functions of spine / The structure and function of segments and divisions of the spinal cord

The structure and function of segments and divisions of the spinal cord

The Segments of the spinal cord are of great importance to humans, because they give the opportunity to feel the world. The spinal cord is closed vertebral skeleton of vertebrae. Human health depends largely on proper operation of the segments of his brain. The brain allows man to control his body, to perceive the world, including through reflexes.

Wrapper spinal cord

What is a spinal cord segment?

Between the intervertebral openings facing spinal nerves formed by roots of the spinal cord. Their number is 31 a couple. The roots of the spinal cord are interconnected, in the end forms the spinal nerve. Fragments of the brain, the roots of which are connected to the nerve, form the segmental apparatus of the spinal cord. How many segments in the spinal cord, and the same pairs of spinal nerves. In rare cases, the number of segments is 32-33 and depends on how many pairs of the spinal cord. The segments are divided into the following:

  • cervical – 8 pairs;
  • thoracic – 12 pairs;
  • lumbar – 5 pairs;
  • sacral – 5 pairs;
  • oil – usually 1 to 3 pairs;
  • brain cone includes sacral and coccygeal parts.

All the elements are designated by Latin letters corresponding to the name of the division, and Roman numerals denoting ordinal segment: C(I-VIII) – cervical, Th(I-XII) thoracic, L(I-X) – lumbar, S(I-V) – sacral, Co(I-III) – coccygeal.

the Segment of the spinal cord

Each element supplies the nerves in their zone and partly zone preceding and following segment.

Reflexes will vary depending on where they occur, but they remain connected. For example, the signal in the cervical spine from the brain, then moves to the thoracic segment and then to other organs and tissues. In the cervical segmental apparatus is the center that regulates pupil dilation. The cervical segment is responsible for vision, here are the centers of distribution of the nerves in the muscles of the upper limb and diaphragmatic division.

In the thoracic region are the centers of distribution of nerves in respiratory muscles, the heart and blood vessels, as well as regulatory sweating and the gastrointestinal tract. The thoracic Department is not responsible for those sites, which are located below.

The Sacral and lumbar segments of the spinal cord are responsible for the activity of the pelvic organs.


the Structure and pathology of the spinal cord

On the structure of the spinal cord the human brain resembles the brain of a frog. The segments look the same: they consist of two roots and cut. If damaged front roots associated with motor function, hence the posterior will not be able to function normally. Similarly, in the reverse situation: when damage to the posterior roots of the work of the front is broken. With nearby elements will affect each other.

The Spinal cord is located in the channel of the spinal column. The length of spinal cord length and spinal column do not match. Men generally have a length of spinal cord is 45 cm In women, usually less than about 3 or 4 see the position of the segments and vertebrae are usually different.

The nature of spinal cord of man is divided into segments, also known as the spinal cord. Each reflex is produced by these departments, has a strict location. So, the knee-jerk reaction occurs in the lumbar and sacral segments. Sacral is responsible for the plantar reflex. The activities of the bronchi in control of the thoracic segments. Damage to these segments can be expressed as a complication of severe infectious or inflammatory diseases.

spinal cord Injury as a result of injuries

Any breach of the normal state the spinal segments can lead to serious implications and always pose a danger to health and life. When the element damage of spinal cord reflexes for which he is responsible are disabled (reflexes, adjustable intact vertebrae above the injury site continue to function).

This phenomenon is called spinal shock. It can manifest several other symptoms depending on location of damage:

  1. trauma to the lower back may deteriorate the internal organs of small pelvis and abdominal cavity. In some cases there are trophic disorders, areflexia.
  2. the Most important division of the spinal cord of vital importance is cervical segments III and IV. Their functions include the regulation of the movement of the diaphragm, its normal operation. If for any reason these segments are damaged, the functioning of the diaphragm is broken. The result is respiratory arrest, which in 75% of cases leads to death.

The spinal cord can provoke a war injury and simple household. Often the reason of damage become disabling brainis associated with spinal. Damage can occur not only at the point where the impact occurred, but in some other. There may develop myelitis, a disorder of the blood and lymph circulation.

Spinal shock will inevitably cause the breakdown of some of the reflexes: autonomic and skeletal-motor. As a result lost the reflexes of the blood vessels, urination, often reduced blood pressure. The state of spinal shock may last long enough to 6 months, after which usually, all the reflexes are restored.

All of these symptoms indicate a serious condition of the patient, but not always can lead to disability. An important factor is the timely seeking professional help. If provided with timely assistance, then after a while all the functions are completely restored, the paralysis wears off.

Injuries in the lumbar segments usually yield positive prediction of treatment, especially if not disturbed sensibility in the limbs and pelvic muscles.