Vertebral column (spine)
Last reviewed: 19.10.2021
All iLive content is medically reviewed or fact checked to ensure as much factual accuracy as possible.
We have strict sourcing guidelines and only link to reputable media sites, academic research institutions and, whenever possible, medically peer reviewed studies. Note that the numbers in parentheses ([1], [2], etc.) are clickable links to these studies.
If you feel that any of our content is inaccurate, out-of-date, or otherwise questionable, please select it and press Ctrl + Enter.
The spine (vertebral column, columna vertebralis) is formed by 33-34 vertebrae, of which 7 cervical, 12 thoracic, 5 lumbar.
The most important support structure of the human body is the spine. Without it, an ordinary person would not have the chances of not walking and running, but even standing without help.
In addition, the spine provides a very important function, consisting in protecting the spinal cord. Most diseases of the spine in modern people occurs due to its upright, as well as a high level of injuries. To better understand all the causes and mechanisms by which this or that disease of this structure operates, and also in order to understand how best to treat a disease, it is necessary to qualitatively understand the basics of anatomy and physiology of the spine and spinal cord.
First, you need to understand what the spine consists of. It consists of 24 small bones, which everyone knows as "vertebrae." Between the two vertebrae are located intervertebral discs, which are a round thin joint liner. In such disks there is a complex morphological structure. The main function is the depreciation of all possible types of loads, in any case arising in the process of activity. Also, disks perform the function of connecting vertebrae to each other.
In addition to discs, all vertebrae are connected by means of special ligaments. Bundles are such formations, in which the main function is to connect bones to each other. For example, tendons can connect bones to muscles. Also, the spine has joints that are strikingly similar to the structure of the knee or elbow joints. Usually they are called facet joints. And it is they who are responsible for the fact that the movement between the vertebrae is possible.
In each vertebra, there are small holes approximately in the center. This is called the vertebral foramen. They are located strictly above each other and form a receptacle for the spinal cord. And why does the spine have a spinal cord? The spinal cord is the central nervous system. In this complex system, nerve pathways are passed that transmit signals to the brain. That is, this thing is very necessary.
The spine is divided into 4 main parts: cervical, thoracic, lumbar and coccygeal. In the cervical region there are 7 vertebrae, the thoracic region has 12 vertebrae, only 5 in the lumbar region. In the lowest part, the lumbar connects with the sacrum. Sacrum - this is also the spine, consisting of 5 intergrown vertebrae. Thanks to the sacrum, the spine is connected to the pelvic bones.
If we take a normal example, it turns out that the spine has a peculiar S-shape. Due to this form, the spine has an additional damping function. The cervical and lumbar regions are an arc, the convex side of which is facing the convex side forward, but the thoracic region is an arch facing backward.
Thus, the human spine is a fairly complex structure, in which one must sit and for a long time understand. However, if you understand all the principles of work that work there, you can avoid a lot of diseases that most people suffer from today. In addition, it will be possible to deal with the treatment of the spine.
Cervical vertebrae (vertebrae cervicales) experience less stress compared to the rest of the spine, so they have a small body. The transverse processes of all cervical vertebrae have an opening of the transverse process (foramen processus transversus). The process ends with tubercles - anterior and posterior. The anterior tubercle of the sixth cervical vertebra is well developed, it is called a sleep tubercle. To it, if necessary, the carotid artery, which passes anterior to this tubercle, may be pressed. The articular processes of the cervical vertebrae are rather short. The articular surfaces of the upper articular processes are turned back and forth, the lower articular processes - forward and downward. The spinous processes of the cervical vertebrae are short, bifurcated at the end. The spinous process of the VII cervical vertebra is longer and thicker than that of the adjacent vertebrae. It is easy to probe for a person, so it is called a protruding vertebra (vertebra prominens).
The thoracic vertebrae (vertebrae thoracicae) are larger than the cervical vertebrae. The height of their body grows from top to bottom. It is maximal in the XII thoracic vertebra. The spinous processes of the thoracic vertebrae are long, inclined downwards and superimposed on each other. This arrangement prevents the spine from re-bending.
The lumbar vertebrae (vertebrae lumbales) have a large bean-shaped body. The height of the body increases in the direction from I to V vertebra.
The sacrum (os sacrum) consists of five sacral vertebrae (vertebrae sacrales), which grow together into one bone in adolescence. The sacrum is triangular in shape. He is a massive bone, because he takes on the weight of almost the entire body.
The coccyx (os caccygis) is the result of the coalescence of 3-5 rudimentary coccygeal vertebrae (vertebrae coccygeae).
The vertebral column is formed by vertebrae, interconnected by intervertebral disks (symphysis), ligaments and membranes. The spine performs a supporting function, is a flexible trunk axis. The spine is involved in the formation of the posterior wall of the thoracic and abdominal cavities, the pelvis, serves as a receptacle for the spinal cord, as well as the place where the muscles of the trunk and limbs begin and attach.
The length of the spine in an adult woman is 60-65 cm, for a man it ranges from 60 to 75 cm. In old age, the spine decreases in size by about 5 cm, which is associated with an increase in the spinal bends and a decrease in the thickness of the intervertebral discs. The width of the vertebrae decreases from the bottom to the top. At the level of XII of the thoracic vertebra, it is 5 cm. The largest diameter (11-12 cm) of the spine is at the level of the base of the sacrum.
The spine forms bends in the sagittal and frontal planes. Bends of the spine bulge back called kyphosis, convex forward - lordosis, in the side - scoliosis. Distinguish the following physiological curves of the spine: cervical and lumbar lordosis, thoracic and sacral kyphosis, thoracic (aortic) physiological scoliosis. Aortic scoliosis is present in about 1/2 cases, it is located at the level of III-V thoracic vertebrae in the form of a small bulge of the vertebral column to the right.
Formation of the bends of the spine occurs only after birth. In the newborn, the spine has the appearance of an arch facing backward. When the baby starts to hold his head, cervical lordosis is formed. Its formation is associated with an increase in the tone of the occipital muscles that hold the head. When standing, walking forms a lumbar lordosis.
The bends that the spine has in the horizontal position of the body are somewhat straightened, with a vertical position expressed more sharply. With loads (wearing weights, etc.), the severity of the bends increases. As a result of painful processes or prolonged incorrect landing of the child in the school, nonphysiological curves of the spine can develop.
Roentgenatomy of vertebrae and their joints
On X-ray images of the spine, the vertebral bodies show two upper and two lower corners with rounded apices. The bodies of the lumbar vertebrae are large, the middle of their narrowed ("waist"). On the background of the sacrum, which has the form of a triangle, its intervertebral openings are projected. Between the bodies of the vertebrae, the spaces occupied by the intervertebral discs are clearly visible. The arch of the vertebra is layered on the image of the body of the corresponding vertebra. The legs of the arches have oval or rounded outlines. Determine the transverse processes located in the frontal plane. The spinous processes are distinguished in the form of a falling drop on the background of the vertebral body. The tips of the spinous processes at the level of the underlying intervertebral space are more clearly visible. The lower articular processes of the vertebra are superimposed on the contours of the upper articular processes of the underlying vertebra and on its body. The spine in the thoracic region of the contour of the head and neck of the rib layer on the transverse process of the thoracic vertebra.
On the radiographs made in lateral projections, the front and back arcs of the atlant, the contours of the atlanto-occluding joint, the axial vertebra tooth and the lateral atlanto-axial joint are clearly visible. The arcs of the vertebrae with articular and articular processes are clearly defined. Intervertebral openings, x-ray articular fissures of arched joints, spinal bends.
What kind of movement does the spine have?
Despite the insignificant mobility of adjacent vertebrae in relation to each other, the spine as a whole has great mobility. The following types of movements of the spine are possible: flexion and extension, retraction and reduction (lateral inclinations), twisting (rotation) and circular motions.
Flexion and extension are performed with respect to the frontal axis. Their total amplitude is 170-245 °. When flexing the body, the vertebrae lean forward, the spinous processes branch away from each other. The anterior longitudinal ligament relaxes. Tension of the posterior longitudinal ligament, yellow ligaments, interstitial and neoplastic ligaments retards this movement.
If the spine unbends relaxes all its ligaments, except the anterior longitudinal. Its tension limits the extension of the spine. Intervertebral discs change their configuration when flexing and expanding. Their thickness decreases on the side of the inclination of the spinal column and increases on the opposite side.
The removal and reduction of the spine are carried out with respect to the sagittal axis. The total swing of these movements is approximately 165 °. If the spine is performing an abduction from the median plane, yellow and interdigitic ligaments are stretched to the side, capsules of arcuate joints on the opposite side. This limits the movement that is being performed.
Rotation of the spine (turning left and right) occurs around the vertical axis. The total swing speed is 120 °. If the spine rotates, the jelly core of the intervertebral disc plays the role of an articular head, and the tension of fibrous bundles of intervertebral discs and yellow ligaments slows down this movement.
Circular movements of the spine also occur around the vertical (longitudinal) axis. In this case, the support point is at the level of the sacrum, and the upper end of the spine (together with the head) freely moves in space, describing the circumference.
If you completely understand this topic, you need to re-read a lot of not very exciting literature, telling about what the spine is, what are its problems and the treatment of its diseases. But in principle, so much time is worth it. Even if only because you will be sick in times less. And also you can prevent the appearance of malignant diseases in close people.