Vertebral column

• Cervical vertebrae ( cervical part )
• Thoracic vertebrae ( thoracic part )
• Lumbar ( lumbar part )
• Tailbone ( coccyx )

The vertebral column (Latin columna vertebral, Greek rachis ) in its entirety is the central load-bearing structural element of vertebrate animals. It provides not only the bony center of the body, it also connects all the other parts of the skeleton together. In addition, the spinal column surrounds the spinal cord lies in the vertebral canal.

In humans, the spinal column of 24 vertebrae which are movably connected by 23 intervertebral discs, and 8 to 10 vertebrae, which are fused to sacrum and coccyx. Since she has to wear almost the entire body weight and distribute them to the legs, the spine below ( caudal ) is thicker than the top ( cranial). Your multiple bending ( " double S " form ) is used to absorb shocks.

The reference to the spine is called vertebral or spinal with the adjectives.

Form

Looking at the spine of a person from the side ( sagittal plane ), it is striking that the individual sections of the spine are shaped differently. The cervical spine has a bend to the front ( ventral) to the thoracic spine arching back, the lumbar spine forward again and sacrum and coccyx as a unit in turn to the back ( dorsal). Kyphosis in the chest area ensures the lungs a good opportunity for development, the lordosis in the cervical and lumbar kyphosis of the same and counteract axial forces and an unfavorable shift in the focus. This results in the appearance of a double S-shaped curvature (lordosis, kyphosis ). This special form of human spine allows upright gait of man and dampens shocks as a spring rod. In this way also the brain from concussions that occur during walking, preserved.

From the back or front views the spine forms a nearly straight line. In a lateral curvature of scoliosis is present.

Sections

From top ( cranial ) to bottom ( caudal ), the spine is divided into five separate sections that make up each of the individual vertebrae ( Vertebrae Latin ). In humans, these are the cervical spine ( cervical part ) with seven vertebrae, the thoracic spine ( thoracic part ) with twelve vertebrae, the lumbar spine ( lumbar part ) with five vertebrae, the sacrum ( os sacrum ) with five synostosis fused vertebrae and the coccyx (os coccyx ) with four to five fused vertebrae rudiments (individually and depending on age). The human spine thus consists of a total of 33 or 34 vertebrae. Since the five vertebrae that form the sacrum, fused as well as the vertebral rudiments of the coccyx together ( fused ) are, it is often also assume that the spine from 24 free ( presacral ) vertebrae ( cervical, thoracic and lumbar ) and the sacrum and the coccyx is.

The basic structure is typical of all mammals, the number of vertebrae is, however, different for each section depending on the species. Tail -bearing vertebrates have a different number of caudal vertebrae.

Structure of the vortex

Vertebral body and spinal canal

Even if the individual vertebrae in the different spinal regions are slightly different from each other in their external form, the general structure is still the same in all sections.

Each vertebra consists of a compact vertebral body, which is followed by the bony vertebral arch. The only exception is the first cervical vertebra ( atlas), which has no compact vertebral body. The vertebral arches form a hole ( vertebral foramen ); the superposition of these holes makes stringing the spinal canal, the parts of the nervous system, especially the spinal cord and its membranes enclosing. The spinal cord extends from the outlet of the first cervical nerve to the conus medullaris, which ends in the adult at the level of the first lumbar vertebra. The vertebral arches of two adjacent vertebrae can be as clearance on each side free of the intervertebral foramen, exiting through the on each floor, a spinal cord nerve ( spinal nerve ) from the spinal canal.

Transverse process and spinous process

On each side of the vertebral arch springs from a transverse process, which has a joint surface of the chest, attach to the ribs. On the back there is the spinous process. These bony projections are ligaments and muscles as starting points. To establish a stable contact of each vertebra to its neighboring vertebrae, they are connected via the small vertebral joints. These facet joints have their origin in the vertebral arches.

The vertebral bodies take on a purely stabilizing effect addition, another important task true. Like many other larger bones form the cells of the blood in which is situated inside her bone marrow.

Vertebral joints

With the exception of the first and second cervical vertebrae and the fused sacrum and coccyx vertebrae two adjacent vertebrae in mammals always by an intervertebral disc ( intervertebral disc ) are interconnected. This is in each case between the two vertebrae and is made of fiber cartilage with a relatively rigid outer ring of the connective tissue and a soft inner core. Tasks of the intervertebral discs are the muffling of bumps and bruises and the movable connection between the individual vertebrae together. The intervertebral discs make up fake joints in the form of symphysis.

In addition to the intervertebral discs, there are real joints between the individual vertebrae, the facet joints. It is flat joints or facet joints on the two lower (aft in animals ) and the two upper ( front ) articular processes adjacent vertebrae lie. The facet joints determine the direction of movement, while the intervertebral discs and spinal ligaments limit the range of motion.

The mobility of the spine in the three movable sections varies widely. In general, the mobility of the cervical spine in all directions is greatest, the thoracic spine is because of their involvement in the chest at the most inflexible. Due to the almost vertical joint surfaces of the articular processes in the lumbar region almost no rotation takes place here, instead, a strong forward flexion ( bending forward) and dorsiflexion (extension to the rear) is possible.

Motion segment

The smallest functional unit of the spine is also called Junghanns cal motion segment or Functional Spinal Unit ( FSU). It consists of two vertebral bodies, the intervertebral disc between them, the corresponding facet joints, and surrounding ligaments, muscles and nerves.

Bands

Bands extend over the entire length of the spinal column and to stabilize it:

• The anterior longitudinal ligament ( anterior longitudinal ) pulls on the front sides of the vertebral body. It represents a stabilizing boundary of the spinal column toward the neck, chest, abdomen and pelvis
• The posterior longitudinal ligament ( posterior longitudinal ) runs over all posterior surfaces of the vertebral bodies. It dresses the spinal canal from in its front area.
• The space between the vertebral arches assume the yellow bands ( ligamentum flava ).
• The intermediate transverse extension bands ( ligaments intertransversaria ) form a system of strong straps connecting the transverse processes of the vertebrae together.
• The intermediate spinous ligaments ( ligaments interspinalia ) form another band system. Pull of the spinous process to spinous process and connect the backs of the individual vertebrae together.
• An all spinous pulling tape that over spinous ligament ( supraspinal ), represents the rearmost stabilizing ligamentous spine dar.

These six bands or band systems are important for spinal stability is of great importance. They are supported by the numerous muscles of the back. Bands give the spine support and mobility. The stabilizing and elastic structures of the spine allow numerous movements.

Movements

• Bending forwards (flexion )
• Extension to the rear ( extension)
• Lateral bending ( lateral flexion )
• Rotary movements (rotation)

Diseases and Abnormalities

Fractures of the spine can lead, inter alia, to kyphosis. If the spinal cord is damaged thereby leading to paraplegia.

The most common diseases are: Degenerative changes of the functional group of the intervertebral disc (→ herniated disc ) and the two adjacent vertebrae ( osteochondritis intervertebralis ) instabilities to spondylolisthesis ( spondylolisthesis ), the rheumatic diseases associated inflammatory diseases (such as ankylosing spondylitis ) and deformations such as scoliosis. The most common growth disorder of the spine is the Scheuermann 's disease.

Chordomas are tumors of the spine. Tuberculosis and other infectious diseases can be manifested in the spine.

The Cervicobrachialsyndrom is a state of pain emanating from the cervical spine and radiates into the arm.

A common malformation that occurs in approximately 10 to 20 % of the population, the so-called spina bifida occulta, which occurs most commonly on the sacrum and the lumbar spine. Here, a vertebral arch is not quite closed, which for the person concerned, however, usually has no consequences and therefore goes unnoticed. Fatal, but also less common is spina bifida, in addition there is a malformation of the spinal cord in the. Malformations can also affect the vertebral body: block vertebrae are two coalesced vertebrae, hemivertebrae at upper and lower half of a vertebral body are not fused together. Block vertebra that restrict the mobility of the spine, while Hemivertebra lead to scoliosis.