Anatomy of the spine

The back of the vertebrae is formed by bony structures that extend from the vertebral body in the form of legs and expand backward to form the vertebral arch. Together with the posterior longitudinal and yellow ligaments, the arch of the vertebra forms the vertebral canal, in which the spinal cord and its roots are located. The posterior parts of the vertebra are articulated with the adjacent vertebrae by two small intervertebral (facet) joints. The intervertebral (facet) joints have a small articular surface, most pronounced in the lumbar spine. These articular areas provide certain mobility of the spine.

The vertebrae posteriorly have strong transverse and spinous bony processes. The transverse processes extend laterally from the vertebral pedicles. The spinous processes run in the posterior direction. Attached to these processes are ligaments and tendons of the back muscles, which set in motion, support, and protect the spinal column.

The center of the intervertebral disc is occupied by the gelatinous nucleus pulposus, which is considered the remnant of embryonic tissue (chord). It is surrounded and supported by a fibrous ring, consisting of fibrous-cartilaginous and connective tissue.

After the completion of the development of the spine (at the age of 24–26 years), the intervertebral discs lose their blood supply vessels. In the future, the intervertebral discs become less elastic and less efficiently cope with the role of shock absorbers when walking. These changes can lead to disorders in the most mobile parts of the spine: in its cervical and lumbar segments.

The following structures give stability to the human spine:

• articulations of the vertebral bodies through the intervertebral discs and intervertebral joints
• ligaments and muscles of the spine

The ligamentous apparatus of the spine has sufficient strength to displacement. The vertebral bodies with the intervertebral disc do not have the same overall strength as the ligaments to withstand displacement under the loads acting on the spinal column during movements. This weakness of the spine is compensated for by the voluntary and reflex contractions of the sacro-vertebral, abdominal, gluteal, and square muscles of the lower back, as well as the hamstring, which provides such stability.

The spinal cord is located in the lumen of the spinal canal. In a child, he fills it almost completely. With the growth of a person, already in adulthood, the cone of the spinal cord reaches only the level of the 1st or 2nd lumbar vertebra, because the nervous tissue does not keep pace with the rapid growth of the bones of the skeleton.

The structures of the spine are innervated from the recurrent branches of the spinal nerves. Painful endings and fibers of this nerve were found in the ligaments, muscles, periosteum of the processes, the outer layers of the fibrous ring of the intervertebral disc, and in the synovium of the intervertebral (facet) joints. Sensory fibers from these structures of the spine and the sacroiliac and lumbosacral joints, joining, form the Luschke's synvertebral nerves, which enter the recurrent branches of the spinal nerves at the S1 and L1-L5 levels in the gray matter of the corresponding segments of the spinal cord. Motor fibers emerge from these segments and reach muscles as part of the same nerves.

The lumbar and cervical spine have the greatest freedom of movement. In comparison with them, the thoracic spine is reliably and firmly fixed by the bones of the chest. Greater mobility of the neck and lower back is the reason for his frequent damage. In addition to voluntary movements that provide flexion and twists of the trunk, many movements of the spine are reflex and ensure the maintenance of the body's position in space, as it happens when walking or running.

Epidural fatty tissue surrounds the lining of the spinal cord. Infection of the epidural tissue leads to purulent spinal epiduritis.

 

We suggest that you familiarize yourself with some useful articles and links related to the work of our clinic:

• Glossary - provides a list of the most common medical terms
• A dictionary of neurological signs - neurological signs and their meaning;
• Frequently Asked Questions - lists the most frequently asked questions by patients
• Anatomy of the spine - basic data on the structure of the spine and spinal cord are given and illustrated
• Anatomy of the nervous system - basic data on the structure of the brain and spinal cord, nerves are given and illustrated
• Rules for preparing the person under study for certain diagnostic procedures
• Nursing rules - presents ways to safely care for bedridden or debilitated patients at home or in a hospital